Tag: Colon Cancer

Neoadjuvant PD-1 Blockade Promotes Organ Preservation in Early Stage Mismatch Repair–Deficient Solid Tumors

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SUMMARY: Colorectal cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23. The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. Defective MMR can be a sporadic or heritable event. Approximately 65% of the MSI high colon tumors are sporadic and when sporadic, the DNA MMR gene is MLH1. Defective MMR can manifest as a germline mutation occurring in MMR genes including MLH1, MSH2, MSH6 and PMS2. This produces Lynch Syndrome often called Hereditary Nonpolyposis Colorectal Carcinoma–HNPCC, an Autosomal Dominant disorder that is often associated with a high risk for Colorectal and Endometrial carcinoma, as well as several other malignancies including Ovary, Stomach, Small bowel, Hepatobiliary tract, Brain and Skin. MSI is a hallmark of Lynch Syndrome-associated cancers. MSI high tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increase immunogenicity. These tumors therefore are susceptible to blockade with immune checkpoint inhibitors.

MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MMR genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). NCCN Guidelines recommend MMR or MSI testing for all patients with a history of Colon or Rectal cancer. Unlike Colorectal and Endometrial cancer, where MSI-H/dMMR testing is routinely undertaken, the characterization of Lynch Syndrome across heterogeneous MSI-H/dMMR tumors is unknown.

Background
Checkpoint inhibitors have revolutionized the treatment landscape for MisMatch Repair–deficient (dMMR) metastatic solid tumors, offering durable responses across tumor types. This paradigm is now being explored in early-stage settings. Dostarlimab (JEMPERLI®) is a monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2. Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response. Building on prior success in dMMR rectal cancer, this Phase 2, multicenter study investigated the feasibility of using neoadjuvant PD-1 blockade with Dostarlimab to achieve organ preservation in early-stage, surgically resectable dMMR solid tumors, potentially shifting the standard of care away from surgery and cytotoxic therapies.

Study Design and Patient Population
Conducted at Memorial Sloan Kettering Cancer Center, Hartford HealthCare, and Baptist Health Miami Cancer Institute, the study enrolled patients with newly diagnosed Stage I–III dMMR solid tumors, defined by loss of MLH1, PMS2, MSH2, or MSH6 expression on immunohistochemistry, that were amenable to curative-intent surgery. Two cohorts were formed:

  • Cohort 1: Patients with locally advanced rectal cancer.
  • Cohort 2: Patients with nonrectal dMMR solid tumors (including esophagogastric, colon, hepatobiliary, genitourinary, and gynecologic cancers).

All patients received Dostarlimab 500 mg IV every 3 weeks for 6 months (nine cycles). Clinical response was assessed within 8 weeks of completing therapy via tumor-specific imaging, endoscopy, and biopsy where applicable. Patients with residual disease were offered standard neoadjuvant therapy and surgery, while those achieving a clinical Complete Response (cCR) could opt for nonoperative management.

Primary and Exploratory Endpoints

  • Cohort 1: Co-primary endpoints were Overall Response Rate and sustained cCR at 12 months post-treatment.
  • Cohort 2: Exploratory analyses evaluated cCR rates, Recurrence-Free Survival (RFS), safety, and molecular correlates of response, including circulating tumor DNA (ctDNA).

Results
A total of 117 patients were analyzed:

  • Cohort 1 (Rectal Cancer): All 49 patients who completed therapy achieved a cCR and declined surgery. At 12 months, 37 maintained a sustained cCR, meeting the efficacy threshold.
  • Cohort 2 (Nonrectal Tumors): Of 54 patients, 35 achieved a cCR, with 33 choosing nonoperative management.

Across both cohorts:

  • 103 patients completed Dostarlimab therapy.
  • 84 (82%) achieved cCR.
  • 82 patients (80%) avoided surgery.
  • Two-year RFS: 92% (95% CI, 86–99).
  • Median follow-up for recurrence: 20 months (range, 0–60.8).
  • Safety: Most adverse events were grade 1–2 (60%), with 35% reporting no treatment-related events. No patient lost the opportunity for curative surgery due to disease progression.

Genomic and ctDNA Findings

  • Germline dMMR variants were present in 44% of patients.
  • Tumor-informed ctDNA testing tracked up to 50 tumor-specific mutations using a highly sensitive and specific assay.
  • ctDNA clearance correlated strongly with cCR: all patients with a cCR showed complete ctDNA clearance by end of treatment.
  • Persistently detectable ctDNA was associated with residual disease or eventual recurrence, reinforcing its value as a real-time, noninvasive biomarker for treatment response and residual disease monitoring.

Discussion
The findings underscore the transformative potential of neoadjuvant PD-1 blockade for early-stage dMMR cancers. Key takeaways include:

  • Tumor-Agnostic Efficacy: Dostarlimab elicited robust responses across a variety of histologies, suggesting that dMMR status, rather than tumor origin, may drive sensitivity to immunotherapy.
  • Organ Preservation: Surgery, and its associated morbidities, was avoided in the majority of patients, including those with rectal cancers where standard treatment often compromises fertility, continence, or other organ functions. Three women with rectal cancer treated in this trial successfully conceived and delivered children.
  • Variable Responses by Histology: While responses were highest in rectal, colon, hepatobiliary, and urothelial cancers, lower cCR rates were observed in prostate and upper gastrointestinal tumors. This suggests underlying biological variability despite shared dMMR status.
  • Monitoring Strategy: Integration of imaging, endoscopy, and ctDNA is critical. Liquid biopsy offered a reliable surrogate for tumor biopsy, particularly in inaccessible tumors, but caution is warranted as ctDNA alone may miss certain cases.
  • Safety and Feasibility: The 6-month regimen was generally well tolerated, and no patient lost surgical eligibility due to disease progression. This supports the feasibility of prolonged neoadjuvant immunotherapy in appropriately selected patients.

Clinical Implications and Future Directions
This study lays the groundwork for a paradigm shift in the management of early-stage dMMR tumors. However, key questions remain:

  • Long-Term Durability: While initial outcomes are promising, especially in rectal cancer, longer follow-up and additional data are necessary to confirm sustained benefit across nonrectal histologies.
  • Histology-Specific Trials: Basket trials and single-arm studies may suffice for anatomically sensitive tumors (e.g., rectum, bladder), but randomized trials may still be appropriate in less morbidly resectable cancers (e.g., colon).
  • Treatment Optimization: Determining the minimal effective duration of immunotherapy could reduce adverse events and cost. Median times to biopsy negativity (1.5 months) and imaging response (6.1 months) suggest a window for shortening therapy in responders.
  • Shared Decision-Making: Given the potential for curative nonoperative management, multidisciplinary care teams must align on strategies and engage patients in informed decision-making, particularly where standard surgery entails long-term quality-of-life tradeoffs.

Conclusion
Neoadjuvant PD-1 blockade with Dostarlimab achieved clinical Complete Responses in a substantial majority of patients with early-stage dMMR tumors, offering a path to organ preservation without compromising curative potential. These results highlight the tumor-agnostic power of checkpoint inhibitors and present a compelling case for redefining the treatment of dMMR solid tumors. As follow-up data matures and histology-specific nuances are better understood, immunotherapy may become the new cornerstone of early-stage dMMR cancer management.

Nonoperative Management of Mismatch Repair–Deficient Tumors. Cercek A, Foote MB, Rousseau B, et al. N Engl J Med 2025;392:2297-2308.

BREAKWATER Trial Establishes Encorafenib Combination with Cetuximab Plus mFOLFOX6 as a First-Line Standard for BRAF V600E–Mutated mCRC

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SUMMARY: Colorectal cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

Advanced colon cancer is often incurable and standard chemotherapy when combined with anti EGFR (Epidermal Growth Factor Receptor) targeted monoclonal antibodies such as Panitumumab (VECTIBIX®) and Cetuximab (ERBITUX®), as well as anti VEGF agent Bevacizumab (AVASTIN®), have demonstrated improvement in Progression Free Survival (PFS) and Overall Survival (OS). The benefit with anti EGFR agents however is only demonstrable in patients with metastatic CRC (mCRC) whose tumors do not harbor KRAS mutations in codons 12 and 13 of exon 2 (KRAS Wild Type). It is now also clear that even among the KRAS Wild Type patient group about 15-20% have other rare mutations such as NRAS and BRAF mutations, which confer resistance to anti EGFR agents. Patients with stage IV colorectal cancer are now routinely analyzed for extended RAS and BRAF mutations. KRAS mutations are predictive of resistance to EGFR targeted therapy.

BRAF is a very important intermediary of the RAS-RAF-MEK-ERK pathway. The BRAF V600E mutations results in constitutive activation of the MAP kinase pathway. Inhibiting BRAF can transiently reduce MAP kinase signaling. However, this can result in feedback upregulation of EGFR signaling pathway, which can then reactivate the MAP kinase pathway. This aberrant signaling can be blocked by dual inhibition of both BRAF and EGFR. It should be noted that BRAF V600E-mutated CRC is inherently less sensitive to BRAF inhibition than Malignant Melanoma.

Encorafenib (BRAFTOVI®) is a BRAF inhibitor and has target binding characteristics that differ from other BRAF inhibitors such as Vemurafenib (ZELBORAF®) and Dabrafenib (TAFINLAR®), with a prolonged target dissociation half-life and higher potency. The FDA in 2020, approved Encorafenib in combination with Cetuximab for the treatment of adult patients with metastatic ColoRectal Cancer (mCRC) with a BRAF V600E mutation

Background and Unmet Need
BRAF V600E mutations are found in approximately 8-10% of metastatic CRC and are associated with aggressive tumor biology, poor prognosis, and limited response to conventional first-line therapies. These patients tend to have aggressive disease with a higher rate of peritoneal metastasis and do not respond well to standard treatment intervention. Approximately 20% of the BRAF-mutated population in the metastatic setting has MSI-High tumors, but MSI-High status does not confer protection to this patient group. Historically, patients with these mutations experienced shorter survival when treated with chemotherapy with or without biologics such as Bevacizumab, compared to their BRAF wild-type counterparts. While the BEACON CRC trial established the Encorafenib plus Cetuximab (EC) doublet as standard in the previously treated setting, the optimal first-line strategy remained undefined.

Design of the BREAKWATER Study
The Phase 3 BREAKWATER trial addressed this gap by evaluating first-line treatment with Encorafenib and Cetuximab, with or without chemotherapy, in patients with previously untreated BRAF V600E-mutated mCRC. Initially designed with three arms (1:1:1), EC: Encorafenib (300 mg PO QD) + Cetuximab (500 mg/m² IV q2w), EC + mFOLFOX6: As above + Oxaliplatin, Leucovorin, and 5-FU and Control/Standard of Care: mFOLFOX6, FOLFOXIRI, or CAPOX with or without Bevacizumab, the protocol was later amended to focus on the EC+mFOLFOX6 (N=236) versus Standard of Care comparison (N=243). The median age was 61 yrs and stratification was based on ECOG performance status and geographic region. Eligible patients had metastatic colorectal adenocarcinoma with measurable disease and a confirmed BRAF V600E mutation, but no prior systemic therapy for metastatic disease. The Primary endpoints included Progression-Free Survival (PFS) and Objective Response Rate (ORR). Secondary endpoints included Overall Survival (OS), Duration of Response (DoR) and Time to Response.

Efficacy Highlights
The results were compelling across both Primary endpoints (ORR and PFS), as well as key Secondary outcomes:

  • Objective Response Rate (ORR):
    EC+mFOLFOX6 achieved a confirmed ORR of 7%, compared with 37.4% in the Standard of Care arm (Odds Ratio, 2.44; P<0.001), with a median Time to Response of approximately 7 weeks. The median Duration of Response was 13.9 months and 10.8 months respectively
  • Progression-Free Survival (PFS):
    The median PFS was 8 months with EC+mFOLFOX6 versus 7.1 months with standard care (Hazard Ratio [HR] for progression or death, 0.53; P<0.001), representing a 47% reduction in risk.
  • Overall Survival (OS):
    Interim analysis demonstrated a median OS of 3 months with EC+mFOLFOX6, more than double the 15.1 months observed in the Standard of Care group (HR for death, 0.49; P<0.001). Twelve and 24 month survival rates favored the investigational arm (80.1% and 52.0%, respectively) over Standard of Care (66.0% and 29.0%).

Notably, survival outcomes with EC+mFOLFOX6 approached those historically seen in BRAF wild-type mCRC, underscoring the potential for targeted therapy to narrow the survival gap.

Subgroup and Secondary Analyses
Benefits of EC+mFOLFOX6 were consistent across prespecified subgroups, including patients with liver metastases or multi-organ involvement. Additionally, median second Progression-Free Survival was longer with EC+mFOLFOX6, reinforcing its value in delivering durable disease control.

Safety Profile
While the incidence of grade ≥3 adverse events was higher in the EC+mFOLFOX6 group (46.1%) compared to standard care (38.9%), toxicity was manageable, and treatment discontinuations remained relatively low. The safety profile was consistent with expectations for the individual agents, and chemotherapy dose reductions were not substantially increased.

Clinical Implications
These findings firmly establish EC+mFOLFOX6 as a new first-line standard for patients with BRAF V600E–mutated mCRC. The dual-targeted approach combined with chemotherapy offers significantly improved outcomes in a population long characterized by poor prognosis. The results also highlight the importance of early integration of targeted therapy, particularly encorafenib, into the treatment paradigm.

Next Steps in BRAF-Targeted Strategies
Although the EC doublet showed some activity, particularly in patients ineligible for chemotherapy, its efficacy was inferior to the triplet regimen. Enrollment into the EC-only arm was halted, and current exploration includes EC combined with FOLFIRI (ongoing in BREAKWATER cohort 3) and EC plus pembrolizumab in MSI-H/dMMR populations (SEAMARK trial).

Conclusion
The BREAKWATER trial demonstrated that first-line treatment with EC+mFOLFOX6 significantly improves Response Rates, Progression-Free Survival, and Overall Survival, compared to standard chemotherapy regimens, in BRAF V600E–mutated mCRC. This represents a transformative advance, closing the gap in outcomes between BRAF-mutated and wild-type mCRC, and setting a new benchmark in precision oncology.

Encorafenib, Cetuximab, and mFOLFOX6 in BRAF-Mutated Colorectal Cancer. Elez E,  Yoshino T,  Shen L, et al., for the BREAKWATER Trial Investigators. N Engl J Med 2025;392:2425-2437

Late Breaking Abstract – ASCO 2025: Adjuvant Immunotherapy Improves Outcomes in Stage III dMMR Colon Cancer: Results from the ATOMIC Trial

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SUMMARY: Colorectal cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23. The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of CRC in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of CRC cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Approximately 10% to 15% of nonmetastatic CRCs exhibit deficient mismatch repair (dMMR), accounting for an estimated 330,000 cases annually worldwide. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. These tumors respond poorly to Fluoropyrimidine-based chemotherapy alone, especially in the adjuvant setting. While immune checkpoint inhibitors are approved for dMMR colorectal cancer in the metastatic setting, their benefit in earlier stages, particularly post-resection, had not been previously established in a prospective trial.

Atezolizumab (TECENTRIQ&reg;) is an anti PD-L1 monoclonal antibody, designed to directly bind to PD-L1 expressed on tumor cells and tumor-infiltrating immune cells, thereby blocking its interactions with PD-1 and B7.1 receptors expressed on activated T cells. PD-L1 inhibition may prevent T-cell deactivation and further enable the activation of T cells.

The Phase 3 ATOMIC trial (NCT02912559), sponsored by the National Cancer Institute and conducted across multiple centers including NCTN sites and the German AIO group investigated whether the addition of Atezolizumab, a PD-L1 checkpoint inhibitor, to standard adjuvant chemotherapy could improve Disease-Free Survival (DFS) in patients with resected Stage III dMMR colon adenocarcinoma.

Study Design and Population
The trial enrolled 712 patients with surgically resected Stage III colon cancer confirmed to have dMMR. Eligibility included patients aged 12 years and older (one pediatric patient was enrolled). MMR status was initially determined locally by immunohistochemistry and subsequently confirmed centrally. Participants were randomized 1:1 to receive:

  • Control arm: mFOLFOX6 (5-Fluorouracil, Leucovorin, and Oxaliplatin) for 6 months (N=357)
  • Experimental arm: mFOLFOX6 plus Atezolizumab (840 mg IV every 2 weeks) for 6 months, followed by maintenance Atezolizumab monotherapy for an additional 6 months (N=355)

Median patient age was 64 yr. 55.1% were female, 84% of tumors were proximal, 46% were clinical low risk (T1-3N1) and 54% were high risk (T4 and/or N2). Stratification was based on nodal status (N1/N1c vs N2), tumor depth (T1-T3 vs T4), and tumor location (proximal vs distal colon). The Primary endpoint was Disease-Free Survival (DFS). Secondary endpoints included Overall Survival (OS) and Adverse Event (AE) profile. At the second interim analysis, median patient follow-up was 37.2 months and 124 DFS events were observed.

Results and Efficacy
After a median follow-up of 37.2 months, the Primary endpoint of DFS was significantly improved in the Atezolizumab arm. The 3-year DFS was 86.4% in the combination arm vs 76.6% in the mFOLFOX6-only arm (Hazard Ratio (HR)=0.50; P< 0.0001, crossing the prespecified efficacy boundary. This represents a 50% relative reduction in the risk of recurrence or death with the addition of Atezolizumab. Importantly, the benefit was consistent across predefined subgroups, including patients over 70 years old and those with both low and high-risk disease (based on T and N-stage). Tumor location, patient sex, and race did not impact the observed treatment benefit.

Safety and Tolerability
Grade 3 or more treatment-related adverse events occurred in 71.7% of patients receiving Atezolizumab plus chemotherapy, compared to 62.1% in those receiving chemotherapy alone. Although the addition of Atezolizumab resulted in a modest increase in toxicity, the side effect profile was consistent with prior experience with checkpoint inhibitors and considered manageable.

Clinical Implications
The ATOMIC trial is the first large, prospective, randomized Phase 3 study to demonstrate a clear benefit from adding immunotherapy to adjuvant chemotherapy in Stage III dMMR colon cancer. As highlighted by the investigators, current adjuvant treatment recommendations for dMMR tumors have historically been extrapolated from studies in mismatch repair–proficient populations or based on retrospective analyses. The robust DFS improvement observed here provides definitive evidence supporting a new treatment paradigm for this molecularly defined subgroup.

Although Overall Survival (OS) data are not yet mature with a median OS follow-up of 42.5 months, early signs are promising. However, future OS analyses may be complicated by the use of subsequent checkpoint inhibitors in patients who recur. The researchers emphasized the clinical relevance of these findings, noting their applicability to both sporadic dMMR cancers and Lynch syndrome associated tumors.

Future Directions
The ATOMIC trial sets a new benchmark for adjuvant therapy in dMMR colon cancer. However, important questions remain. Chief among them is the optimal duration of immunotherapy in this setting. Atezolizumab was administered for nearly a year, including maintenance. Ongoing research should clarify whether such prolonged treatment is necessary or if shorter regimens could maintain efficacy while reducing toxicity.

Moreover, while this study confirms benefit in the postoperative setting, parallel efforts are warranted to evaluate checkpoint inhibition in the neoadjuvant context. Encouraging responses such as those seen in small studies of neoadjuvant immunotherapy in dMMR rectal cancer highlight the need to explore earlier immunotherapeutic intervention in colon cancer as well.

Conclusion
The ATOMIC trial provides compelling evidence that incorporating Atezolizumab into adjuvant therapy improves Disease-free survival in patients with Stage III dMMR colon cancer, marking a major advancement in the management of this biologically distinct subset. Given these results, the combination of Atezolizumab and mFOLFOX6 should be considered the new standard of care in this setting. This trial also exemplifies the power of cooperative group studies in driving progress for biomarker-defined subsets within common malignancies.

Randomized trial of standard chemotherapy alone or combined with atezolizumab as adjuvant therapy for patients with stage III deficient DNA mismatch repair (dMMR) colon cancer (Alliance A021502; ATOMIC). Sinicrope F, Ou F-S, Arnold D, et al. J Clin Oncol 43, 2025 (suppl 17; abstr LBA1)

OPDIVO® (Nivolumab) with YERVOY® (Ipilimumab)

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The FDA on April 8, 2025, approved OPDIVO® with YERVOY® for adult and pediatric patients 12 years of age and older with unresectable or metastatic MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR) ColoRectal Cancer (CRC). The FDA also converted the accelerated approval to regular approval for single agent OPDIVO® for adult and pediatric patients 12 years of age and older with MSI-H or dMMR metastatic CRC, that has progressed following Fuoropyrimidine, Oxaliplatin, and Irinotecan. OPDIVO®  and YERVOY® are products of Bristol Myers Squibb Company.

Rising Incidence of Pancreatic and Colorectal Adenocarcinoma among Younger Populations

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SUMMARY: The American Cancer Society estimates that in 2025, about 67,440 people will be diagnosed with pancreatic cancer and 51,980 people will die of the disease. Detecting cancer at early stages can significantly increase survival rates and outcomes. Pancreatic Ductal AdenoCarcinoma (PDAC) is one of the most lethal malignancies, ranking among the leading causes of cancer-related mortality globally. A significant challenge in improving PDAC outcomes is its frequent diagnosis at an advanced stage, when therapeutic options are limited and prognosis is poor, with a 5-year survival rate of approximately 10%. Early detection is critical to expanding treatment possibilities and enhancing survival rates. Colorectal cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. Even though the diagnosis of colorectal cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of colorectal cancer cases diagnosed in people under age 50, leading to revisions in screening guidelines.

Study Objective
To provide an updated analysis of Annual Percentage Changes (APCs) in the incidence of pancreatic and colorectal adenocarcinoma across different age groups, focusing on younger populations, using data from the SEER database (2000–2021).

Methods
Data Source

  • SEER (Surveillance, Epidemiology, and End Results) database (22 registries, ~47.9% of US population)
  • Data updated through April 17, 2024

Study Design

  • Retrospective cohort study
  • Inclusion: Pancreatic and colorectal adenocarcinoma only
  • Exclusion: Rare pancreatic cancer subtypes (e.g., neuroendocrine tumors, mucinous cystadenocarcinoma)
  • The Rutgers University IRB exempted the study, and informed consent was not needed owing to the deidentified nature of the data.

Analysis

  • Yearly incidence rates per 100,000 population
  • Annual Percentage Changes (APCs) and 95% confidence intervals calculated for three age groups:
    • 15–34 years
    • 35–54 years
    • 55+ years

Results
Pancreatic Adenocarcinoma

  • Total cases (2000–2021): 275,273
    • 51.8% male, 87.1% aged ≥55 years
  • APC in 15–34 years: 4.35% (95% CI, 2.03–6.73)
  • APC in 35–54 years: 1.54% (95% CI, 1.18–1.90)
  • APC in 55+ years: 1.74% (95% CI, 1.59–1.89)

The APC for pancreatic adenocarcinoma in the group aged 15 to 34 year was statistically significantly higher than the APCs of 1.74 (P =0.007) for the group aged 55 years and older and 1.54 (P =0.004) for the group aged 35 to 54 years. The authors commented that the dramatic increase in the APC in the younger population suggests that close attention should be paid to this trend.

Colorectal Adenocarcinoma

  • Total cases: 1,215,200
    • 52.8% male, 80.4% aged ≥55 years
  • APC in 15–34 years: 1.75% (95% CI, 1.08–2.42)
  • APC in 35–54 years: 0.78% (95% CI, 0.51–1.06)
  • APC in 55+ years: -3.31% (95% CI, -3.54 to -3.08)

The APC for colorectal adenocarcinoma for the group aged 55 years and older was statistically significantly lower than the APCs for the group aged 15 to 34 years (P =0.001) and for the group aged 35 to 54 years (P =0.002). Most declines in colorectal cancer incidence was attributed to increased screening in older adults. Screening age was lowered from 50 to 45 years and may likely reduce future incidence in those aged 35–54.

Interpretation & Implications

Pancreatic Cancer

  • Though rare, pancreatic adenocarcinoma in young adults (15–34 years) is rising at an alarming rate.
  • Potential contributors: Smoking, alcohol, environmental exposures, though definitive causes remain unclear.
  • Clinician awareness is critical when evaluating younger patients with:
    • Abdominal pain
    • Weight loss
    • Anemia
    • Family history of pancreatic cancer

Clinical Insight: Historically, the above findings are not investigated in a young individual. It is therefore important to make sure a serious condition is not missed.

Colorectal Cancer

  • Increasing in younger groups, despite an overall declining trend.
  • This supports recent screening age revisions and highlights the need for vigilance in symptomatic young patients.

Limitations

  • SEER data covers ~47.9% of the U.S. population.
  • However, SEER is designed for accurate trend analysis and has reliable coding for common cancers like pancreatic and colorectal adenocarcinoma.
  • Restricting to adenocarcinoma improves the homogeneity and accuracy of the study.

Conclusions

  • Pancreatic adenocarcinoma incidence is rising in all age groups, especially in the youngest cohort (15–34 years).
  • Colorectal adenocarcinoma is increasing among younger individuals, while declining among those 55 and older.
  • Clinicians must heighten awareness of these trends and consider appropriate workups in symptomatic younger patients.

Key Takeaways

  • Pancreatic adenocarcinoma incidence rose >4% annually in individuals aged 15–34 years.
  • Colorectal adenocarcinoma also increased among patients aged 15–34 years.
  • Consider early imaging and endoscopic evaluations in symptomatic young adults.
  • Continue to support early screening efforts, especially for high-risk individuals.

Incidence of Pancreas and Colorectal Adenocarcinoma in the US. Bussetty A, Shen J, Benias PC, et al. JAMA Netw Open. 2025;8(4):e254682. doi:10.1001/jamanetworkopen.2025.4682

 

 

 

 

 

FDA Approves OPDIVO® Plus YERVOY® for Unresectable or Metastatic MSI-H/MMR Deficient Colorectal Cancer

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SUMMARY: The FDA on April 8, 2025, approved Nivolumab (OPDIVO®) with Ipilimumab (YERVOY®) for adult and pediatric patients 12 years of age and older with unresectable or metastatic MicroSatellite Instability-High (MSI-H) or MisMatch Repair deficient (dMMR) colorectal cancer (CRC). The FDA also converted the accelerated approval to regular approval for single agent Nivolumab for adult and pediatric patients 12 years of age and older with MSI-H or dMMR metastatic CRC, that has progressed following Fluoropyrimidine, Oxaliplatin, and Irinotecan.

Colorectal cancer is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23. The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. Defective MMR can be a sporadic or heritable event. Approximately 65% of the MSI high colon tumors are sporadic and when sporadic, the DNA MMR gene is MLH1. Defective MMR can manifest as a germline mutation occurring in MMR genes including MLH1, MSH2, MSH6 and PMS2. This produces Lynch Syndrome often called Hereditary Nonpolyposis Colorectal Carcinoma – HNPCC, an Autosomal Dominant disorder that is often associated with a high risk for Colorectal and Endometrial carcinoma, as well as several other malignancies including Ovary, Stomach, Small bowel, Hepatobiliary tract, Brain and Skin. MSI is a hallmark of Lynch Syndrome-associated cancers. MSI high tumors tend to have better outcomes and this has been attributed to the abundance of tumor infiltrating lymphocytes in these tumors from increase immunogenicity. These tumors therefore are susceptible to blockade with immune checkpoint inhibitors.

MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors. Tumors considered MSI-H have deficiency of one or more of the DNA MMR genes. MMR gene deficiency can be detected by ImmunoHistoChemistry (IHC). NCCN Guidelines recommend MMR or MSI testing for all patients with a history of Colon or Rectal cancer. Unlike Colorectal and Endometrial cancer, where MSI-H/dMMR testing is routinely undertaken, the characterization of Lynch Syndrome across heterogeneous MSI-H/dMMR tumors is unknown.

Nivolumab is a fully human, immunoglobulin G4 monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with PD-L1 and PD-L2, whereas Ipilimumab is a fully human immunoglobulin G1 monoclonal antibody that blocks Immune checkpoint protein/receptor CTLA-4 (Cytotoxic T-Lymphocyte Antigen 4, also known as CD152). Blocking the Immune checkpoint proteins unleashes the T cells, resulting in T cell proliferation, activation and a therapeutic response.

The present FDA approval is based on CheckMate 8HW, which is an ongoing Phase III, multinational, open-label, randomized trial evaluating Nivolumab plus Ipilimumab as compared with Nivolumab alone or chemotherapy, in patients with MSI-H or dMMR metastatic CRC. In this study, patients with unresectable or mCRC and MSI-H/dMMR status by local testing who had received 0-1 prior line of therapy were randomly assigned in a 2:2:1 ratio to receive either Nivolumab monotherapy (N=353), Nivolumab plus Ipilimumab combination therapy (N=354), or the investigator’s choice of chemotherapy (mFOLFOX6 or FOLFIRI with or without Bevacizumab or Cetuximab (N=132). Patients who had previously received two or more prior lines of therapy for unresectable or metastatic disease were randomly assigned, in a 1:1 ratio, to receive Nivolumab plus Ipilimumab or Nivolumab alone. In the Nivolumab monotherapy arm, patients received Nivolumab 240 mg IV once every two weeks for six doses, followed by 480 mg IV every four weeks. In the Nivolumab plus Ipilimumab arm, patients were given Nivolumab 240 mg IV plus Ipilimumab 1mg/kg IV every three weeks for four doses, followed by Nivolumab 480 mg IV every four weeks. The median patient age was 64 years and tumor location was in the right colon in two thirds of the patients. Treatments continued until disease progression or unacceptable toxicity in all treatment groups or a maximum of 2 years. The dual Primary end points were Progression-Free Survival (PFS) as determined by Blinded Independent Central Review (BICR) comparing Nivolumab plus Ipilimumab to chemotherapy in the first-line therapy setting, and PFS comparing Nivolumab monotherapy to Nivolumab plus Ipilimumab across all lines of therapy, in patients with centrally confirmed MSI-H/dMMR metastatic CRC. At a median follow-up of 31.5 months the results from the prespecified interim analysis (the primary analysis) showed that the PFS outcomes were significantly better with Nivolumab plus Ipilimumab than with chemotherapy (HR=0.21; P<0.001).

The researchers herein reported the first results from the other dual Primary endpoint of PFS for Nivolumab plus Ipilimumab versus Nivolumab monotherapy across all lines of therapy in patients with centrally confirmed MSI-H/dMMR metastatic CRC. Of all the randomized patients 296 in the Nivolumab plus Ipilimumab group and 286 in the Nivolumab monotherapy group had centrally confirmed MSI-H/dMMR status. With a median follow-up of 47.0 months, Nivolumab plus Ipilimumab demonstrated clinically meaningful and statistically significant improvement in PFS by BICR versus Nivolumab monotherapy, with a median PFS Not Reached (NR) in the Nivolumab plus Ipilimumab group, compared to 39.3 months for those on Nivolumab monotherapy (HR=0.62; P= 0.0003). The PFS rates at 12, 24, and 36 months were higher in the Nivolumab plus Ipilimumab group at 76%, 71%, 68% versus 63%, 56%, 51% for Nivolumab monotherapy. The Objective Response Rate (ORR) was significantly higher with Nivolumab plus Ipilimumab at 71%, compared to 58% with Nivolumab alone (P=0.0011). No new safety concerns were identified.

It was concluded that the CheckMate 8HW study met its dual Primary endpoints, with Nivolumab plus Ipilimumab demonstrating a statistically significant and clinically meaningful improvement in PFS compared to Nivolumab monotherapy across all lines of therapy in MSI-H/dMMR metastatic CRC. Moreover, Nivolumab plus Ipilimumab was associated with higher ORR, confirming its potential as a new standard of care for patients with MSI-H/dMMR metastatic CRC. The CheckMate 8HW study is a pivotal contribution to the treatment landscape of MSI-H/dMMR metastatic Colorectal cancer, providing compelling evidence for the use of Nivolumab plus Ipilimumab in the first-line and beyond.

Nivolumab plus ipilimumab versus nivolumab in microsatellite instability-high metastatic colorectal cancer (CheckMate 8HW): a randomised, open-label, phase 3 trial. Andre T, Elez E, Lenz H-J, et al. The Lancet. 2025; 405:383-395

Late Breaking Abstract – 2025 ASCO GI Symposium: Circulating Tumor DNA (ctDNA) as a Predictive Biomarker for Celecoxib Benefit in Stage III Colon Cancer: Insights from CALGB/SWOG 80702

RR

SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

It is estimated that approximately 30% of patients with Stage II or III CRC and 60-70% of patients after oligometastatic resection experience recurrence. Adjuvant chemotherapy for patients with resected, locally advanced, node-positive (Stage III) colon cancer has been the standard of care since the 1990s. However, not all patients with Stage III disease benefit from adjuvant chemotherapy. In the IDEA trial, the absolute Disease Free Survival benefit of adjuvant chemotherapy for the lowest-risk Stage III group and the highest-risk group was 8% and 20%, respectively, suggesting that a substantial number of patients with low-risk Stage III cancer can safely forgo adjuvant chemotherapy or be considered for treatment de-escalation.

More recent data suggests that platelets may play a role in tumorigenesis as well, through the release of angiogenic and growth factors due to overexpression of Cyclooxygenase 2 (COX-2). Aspirin and COX-2 inhibitors such as Celecoxib have been associated with a reduced risk of colorectal polyps and cancer in observational and randomized studies.

The CALGB/SWOG 80702 is a randomized Phase III trial conducted to determine if the addition of Celecoxib to adjuvant chemotherapy with Fluorouracil, Leucovorin, and Oxaliplatin (FOLFOX) improves Disease-Free Survival (DFS) in patients with Stage III colon cancer. Patients were randomized to receive adjuvant FOLFOX (every 2 weeks) for 3 versus 6 months with or without 3 years of Celecoxib (400 mg orally daily; N=1263) versus placebo; N=1261). In this study, the addition of Celecoxib for 3 years to standard adjuvant chemotherapy did not significantly improve Disease-Free Survival (DFS).

The present analysis evaluated the prognostic and predictive value of circulating tumor DNA (ctDNA) in identifying a subpopulation of patients in the above study, who may potentially benefit from Celecoxib therapy. A subset of 1,011 patients from the CALGB/SWOG 80702 trial with adequate biospecimen availability was included in this analysis. ctDNA status was assessed using a tumor-informed, clinically validated 16-plex multiplex Polymerase Chain Reaction Next-Generation Sequencing (mPCR-NGS) assay (Signatera(TM), Natera, Inc.). Plasma samples were collected post-surgery and before the initiation of adjuvant chemotherapy. Survival outcomes, including DFS and Overall Survival (OS), were analyzed using Kaplan-Meier estimates and Cox proportional hazards models.

Results:

  • Of the 1,011 patients with ctDNA data, 189 (18.7%) tested ctDNA-positive.
  • ctDNA positivity correlated with male sex, advanced T stage, and N2 nodal disease.
  • Patients with detectable ctDNA had significantly worse outcomes:
    • DFS: Hazard Ratio (HR)=6.52; P<0.0001
    • OS: HR=6.28; P<0.0001
  • Three-year DFS rates were:
    • 6% in ctDNA-negative patients
    • 8% in ctDNA-positive patients
  • Celecoxib did not significantly impact DFS in ctDNA-negative patients (HR=0.75; P=0.095, 3-year DFS: 87.7% vs. 85.5%).
  • However, in ctDNA-positive patients, Celecoxib was associated with a notable improvement in DFS (HR=0.59; P=0.004, 3-year DFS: 44.1% vs. 26.6%).
  • OS trends mirrored those observed for DFS:
    • ctDNA-negative group: HR=0.86 (P=0.49) with Celecoxib versus placebo.
    • ctDNA-positive group: HR=0.63 (P=0.028) with Celecoxib versus placebo.
  • Multivariate analysis confirmed a statistically significant benefit of Celecoxib in ctDNA-positive patients.

Conclusion: ctDNA serves as a strong prognostic biomarker for both DFS and OS in Stage III colon cancer. Furthermore, ctDNA positivity appears to predict a significant therapeutic benefit from adjuvant Celecoxib, suggesting its potential role in stratifying patients for COX-2 inhibitor therapy. These findings highlight the utility of ctDNA assessment in guiding adjuvant treatment decisions and optimizing personalized therapeutic strategies in colon cancer.

Clinical Implications:

  • Post-surgical ctDNA testing can help identify patients at elevated risk of recurrence.
  • Celecoxib may offer a survival advantage for ctDNA-positive patients when used alongside standard FOLFOX chemotherapy.
  • Further research is warranted to elucidate the role of ctDNA-guided treatment in personalizing colon cancer therapy.

Prognostic and predictive role of circulating tumor DNA (ctDNA) in stage III colon cancer treated with celecoxib: Findings from CALGB (Alliance)/SWOG 80702. Nowak JA, Shi Q, Twombly T, et al. J Clin Oncol. 2025;43(4):LBA14.

Late Breaking Abstract – 2025 ASCO GI Symposium: Personalized Neoantigen Vaccine in Metastatic Colorectal Cancer

RR

SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23.

The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

The DNA MisMatchRepair (MMR) system is responsible for molecular surveillance and works as an editing tool that identifies errors within the microsatellite regions of DNA and removes them. Defective MMR system leads to MSI (Micro Satellite Instability) and hypermutation, with the expression of tumor-specific neoantigens at the surface of cancer cells, triggering an enhanced antitumor immune response. MSI is therefore a hallmark of defective/deficient DNA MisMatchRepair (dMMR) system and occurs in 15% of all colorectal cancers. MSI testing is performed using a PCR or NGS based assay and MSI-High refers to instability at 2 or more of the 5 mononucleotide repeat markers and MSI-Low refers to instability at 1 of the 5 markers. Patients are considered Micro Satellite Stable (MSS) if no instability occurs. MSI-L and MSS are grouped together because MSI-L tumors are uncommon and behave similar to MSS tumors.

Checkpoint inhibitors have revolutionized cancer treatment. They are however not as effective in patients with “cold tumors” (MSS), as these tumors effectively hide themselves from the immune system and do not trigger an immune response following treatment with checkpoint inhibitors.

GRANITE is a personalized neoantigen immunotherapy designed to trigger a strong T-cell immune response against a patient’s tumor. A biopsy of the tumor is performed to identify unique mutations (neoantigens) present in the tumor of patients. An AI platform, EDGE, developed and designed by Gritstone Bio is able to identify critical T-cell vaccine targets, and predict which neoantigens are most likely to be recognized by the immune system of patients. The system has an 80% accuracy rate in selecting the top 20 most immunogenic neoantigens, most likely to generate an immune response in a given patient. The selected neoantigens are incorporated into a chimpanzee adenovirus-based primer vaccine and a Self-Amplifying mRNA (SAM) booster vaccine to train the immune system that leads to an induction of both cytotoxic T-lymphocyte and memory T-cell dependent immune responses, that specifically target and destroy the patients cancer cells that express these neoantigens. This vaccine (GRANITE) is administered via intramuscular injection alongside immune checkpoint inhibitors. Thus GRANITE primes the immune system to recognize and attack these tumors. This vaccine is customized for each patient based on the unique mutations of their tumor. In essence, GRANITE helps make the “cold tumors” visible to the immune system, potentially improving patient outcomes.

GRANITE immunotherapy regimen was evaluated in combination with Nivolumab and Ipilimumab, and compared to the combination of Nivolumab and Ipilimumab alone in a Phase1/2 involving patients with advanced metastatic solid tumors. This study demonstrated robust T-cell activation against targeted neoantigens with no dose-limiting toxicities, and over 50% of patients had a reduction in their circulating tumor DNA (ctDNA) and improved Overall Survival (Palmer CD, et al. Nature 2022).

GRANITE immunotherapy regimen is now being studied as first line metastatic treatment in a randomized Phase 2 trial, among patients with Microsatellite-Stable (MSS) Colorectal cancer patients. GO-010 is an ongoing Phase 2/3, randomized, open-label, multi-center study evaluating the efficacy and safety of GRANITE immunotherapy regimen in combination with Checkpoint Inhibitors (CPIs) as an add-on to Fluoropyrimidine/Bevacizumab as maintenance treatment, following first line therapy with FOLFOX/Bevacizumab, in patients with mCRC. In this study, 104 patients were randomized in a 1:1 ratio, and 67 patients were included in this treated analysis with 39 patients assigned to the GRANITE arm and 28 patients to the control arm. (36 patients withdrew from the study primarily due to early progressive disease or withdrawal of consent, and one patient has yet to begin study treatment). The vaccine manufacturing success rate was 100%. Both treatment groups were well balanced with regards to demographics, clinical characteristics stage, sidedness and presence of liver metastases. Approximately 75% of patients had liver metastases. For the Phase 2 portion of this study, the Primary end point being assessed is molecular response defined as 30% or more decrease from baseline in ctDNA. For the Phase 3 portion of this trial, the Primary end point is Progression Free Survival (PFS). Secondary end points for both Phase 2 and 3 include Adverse Events, Overall Survival (OS), Overall Response Rate (ORR), Duration of Response (DoR) and Clinical Benefit Rate.

Preliminary data from the Phase 2 portion of a Phase 2/3 study showed a positive early trend in PFS for GRANITE immunotherapy patients with a Hazard Ratio (HR) of 0.82 in all patients, HR of 0.52 in high-risk patients1 (more than 90% with liver metastases). The median PFS was 12 months with GRANITE immunotherapy versus 7 months for the control group. Long-term ctDNA responses aligned with positive PFS trend favoring GRANITE immunotherapy patients versus control patients.

In the high-risk group, between first blood draw (time of randomization) and last blood draw (most recent study visit), the ctDNA shifted from high (more than 2% VAF-Variant Allele Frequency) to low (2% or less VAF) in 56% of patients treated with GRANITE immunotherapy versus 22% of control patients. Progressive disease was observed in 44% versus 78% respectively, within this group.

In the low-risk group of patients whose ctDNA was negative after induction chemotherapy, sustained ctDNA negativity was observed in 67% of GRANITE immunotherapy recipients versus 38% in the control patients. Progressive disease was observed in 11% and 38% of these patients, respectively. GRANITE immunotherapy was well tolerated and vast majority of adverse events were Grade1/2 and no patients discontinued study treatment due to an adverse event.

In conclusion, this preliminary Phase 2 results are highly encouraging and suggested that GRANITE immunotherapy demonstrated positive early PFS and long-term ctDNA responses, compared with Fluoropyrimidine/Bevacizumab alone, in front-line metastatic MSS-Colorectal cancer, providing the rationale for a confirmatory Phase 3 trial.

A randomized phase 2 study of an individualized neoantigen-targeting immunotherapy in patients with newly diagnosed metastatic microsatellite stable colorectal cancer (MSS-CRC). Hecht JR, Spira AI, Nguyen AV, et al. J Clin Oncol 43, 2025 (suppl 4; abstr LBA13). DOI 10.1200/JCO.2025.43.4_suppl.LBA13

Late Breaking Abstract – 2025 ASCO GI Symposium: Aspirin Reduces Recurrence in Colorectal Cancer Patients with PI3K Pathway Alterations

RR

SUMMARY: ColoRectal Cancer (CRC) is the third most common cancer diagnosed in both men and women in the United States. The American Cancer Society estimates that approximately 154,270 new cases of CRC will be diagnosed in the United States in 2025 and about 52,900 patients will die of the disease. The lifetime risk of developing CRC is about 1 in 23. Among patients with Stage II-III CRC, 20-40% will develop metastatic disease.

The majority of CRC cases (about 75 %) are sporadic whereas the remaining 25 % of the patients have a family history of the disease. Only 5-6 % of patients with CRC with a family history background are due to inherited mutations in major CRC genes, while the rest are the result of accumulation of both genetic mutations and epigenetic modifications of several genes. Colorectal Cancer is a heterogeneous disease classified by its genetics, and even though the diagnosis of Colorectal Cancer in the US is dropping among people 65 years and older, the incidence has been rising in the younger age groups, with 12% of Colorectal Cancer cases diagnosed in people under age 50.

Aspirin (AcetylSalicylic Acid) has been studied as a chemopreventive agent for several decades and the temporal relationship between systemic inflammation and cancer has been a topic of ongoing investigation. The US Preventive Services Task Force (USPSTF) found adequate evidence that Aspirin use reduces the incidence of CRC in adults after 5-10 years of use, and recommends initiating low-dose Aspirin use for the primary prevention of CardioVascular Disease (CVD) and CRC, in adults aged 50-69 years, who have a 10% or greater 10-year CVD risk, are not at increased risk for bleeding, have a life expectancy of at least 10 years, and are willing to take low-dose Aspirin daily for at least 10 years.

Aspirin has been shown to lower the incidence of adenomas and CRC in high-risk patients. Additionally, observational studies suggest that treatment with Aspirin following diagnosis improves Disease-Free Survival (DFS) in unselected populations. Furthermore, retrospective findings indicate that somatic PIK3CA mutations predict treatment response to Aspirin. However this has not been validated in randomized trials.

The ALASCCA trial was designed to find the impact of Aspirin, on the recurrence of CRC with PI3K pathway mutations. The ALASCCA trial is a randomized, double-blind, multicenter, placebo-controlled trial conducted across 33 hospitals in Sweden, Denmark, Finland, and Norway. Researchers screened 3,508 patients diagnosed with Stage II or III colon cancer or Stage I, II, or III rectal cancer and identified 1,103 individuals with PI3K pathway mutations. Participants were categorized into two groups:

• Group A (N=515): Patients with a PIK3CA mutation in exon 9 and/or 20.
• Group B (N=588): Patients with other PI3K mutations, including PIK3CA mutations outside exon 9/20 or mutations in PIK3R1 or PTEN genes.

Of the 626 patients (419 with colon cancer and 207 with rectal cancer) who continued participation in this trial, 157 and 156 patients in Groups A and B respectively, received Aspirin 160 mg daily for 3 years, whereas 157 and 156 patients in each respective group received placebo. The median age was 66 years, 52% of patients were female, and majority of patients were white. Fifty percent of patients with both rectal and colon cancer had received neoadjuvant therapy. The Primary end point was Time to CRC recurrence (TTR). Secondary end points included Disease Free Survival (DFS) in Group A, TTR in Group B, DFS in Group B, and Safety.

The study met its Primary end point and demonstrated that Aspirin use significantly reduced the risk of CRC recurrence. After 3 years of follow up in Group A, patients taking Aspirin had a 51% lower recurrence risk compared to the placebo group (HR=0.49; P=0.044). In Group B, patients taking Aspirin experienced a 58% reduction in recurrence risk versus the placebo group (HR=0.42; P=0.013). Overall, across all groups, Aspirin was associated with a 55% reduced risk of recurrence compared to placebo. There was no statistically significant difference in 3-year DFS rates among those who received Aspirin versus placebo in Group A (88.5% versus 81.4%, respectively; HR=0.61; P =0.091). There was however significantly improved DFS rates in Group B with Aspirin use (89.1% versus 78.7%, respectively; HR=0.51; P=0.17). Severe side effects of daily Aspirin use were rare.

The researchers concluded that this landmark study provides compelling evidence for the role of low-dose Aspirin in reducing colorectal cancer recurrence in patients with PI3K pathway mutations. By integrating precision medicine with a widely available drug, the ALASCCA trial sets the stage for a new standard in colorectal cancer management.

Low-dose aspirin to reduce recurrence rate in colorectal cancer patients with PI3K pathway alterations: 3-year results from a randomized placebo-controlled trial. Martling A, Lindberg J, Myrberg IH, et al. J Clin Oncol. 2025;43(4):LBA125.