Tag: Breast Cancer

Less Frequent Mammography after Curative Treatment in Older Women with Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S.

Currently, the major national health care organizations in the US have different recommendations for screening mammography which has led to some confusion and emotional counterarguments. These several different recommendations include 1) Annual screening at ages 40 to 84 years 2) Annual screening at ages 45 to 54 years and then biennially at ages 55 to 79 years 3) Biennial screening at ages 50 to 74 years.
Elderly women with a history of breast cancer have a higher risk for a second breast cancer diagnosis. However, appropriate mammographic surveillance methods for this patient group, remains unclear. The widespread practice of annual surveillance mammograms for an unspecified period of time after treatment for early breast cancer can be a significant burden of health care costs in the US.

Mammo-50 trial is a multicenter, randomized Phase III study conducted to assess annual mammography versus less frequent mammography for up to 9 years, in women 50 years or older at the time of their diagnosis with breast cancer. The goal of this study was to determine the optimum frequency and duration of mammographic surveillance. In this study 5,235 women were randomly assigned 1:1 to undergo annual mammograms (N=2618) or less frequent mammograms (N=2617). Less frequent mammography was defined as every 2 years in patients who underwent breast-conservation surgery (N=2099) and every 3 years in patients who had a mastectomy (N=518). Eligible enrolled patients were 50 years of age or older, had undergone curative-intent treatment for invasive or non-invasive breast cancer, and were 3 years post-surgery. Approximately 83% of women were aged 55-75 years, and 87% had invasive disease between the two cohorts. The compliance rates were 83% for the annual mammogram group and 69% for the less frequent mammography group. Approximately 35% of patients missed mammograms due to the COVID-19 pandemic. The Primary study outcomes were Breast Cancer-specific survival and cost effectiveness, whereas Secondary outcomes included Recurrence Free Interval and Overall Survival.

The researchers noted that the efficacy outcomes with regards to breast cancer-specific survival, 5-year recurrence-free interval and OS were similar between the two cohorts of patients. The breast cancer-specific survival at 5 years was 98.1% among patients in the annual mammography cohort and 98.3% among patients in the less frequent mammography cohort. The 5-year Recurrence Free interval rates were 94.1% for the annual mammography group and 94.5% among patients in the less frequent mammography cohort. The 5-year Overall Survival was 94.7% in the annual mammography cohort and 94.5% in the less frequent mammography cohort. Even though compliance in the less frequent mammography group was lower, a sensitivity analysis confirmed this had no effect on the outcomes.

It was concluded from this trial that less frequent mammograms were no worse than undergoing annual mammograms for this group of women,

Mammographic surveillance in early breast cancer patients aged 50 years or over: Results from the Mammo-50 non-inferiority trial of annual versus less frequent mammography. Dunn JA, Donnelly P, Elbeltagi N, et al. Presented at SABCS 2023. December 5-9, 2023. San Antonio, TX. Abstract GS03-02.

Omitting Adjuvant Radiation Therapy in Younger Low Risk Postmenopausal Patients

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S. About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor-positive (HR-positive), HER2-negative breast cancer is the most frequently diagnosed molecular subtype.

Patient undergoing breast conserving surgery, often receive adjuvant breast radiation therapy to reduce the risk of local recurrence. Radiation therapy however is inconvenient, expensive and can be associated with acute and late toxicities. Several previously published trials explored the omission of radiotherapy in low risk patients, following Breast Conservative Surgery. In the CALGB 9343 trial involving women 70 years or older with Stage I, ER-positive breast cancer, treated with Breast Conservative Surgery, locoregional recurrence at 10 years was 10% among those randomly assigned to omission of radiotherapy group and 2% among those assigned to radiotherapy. Similarly, in the PRIME II trial, women 65 years and older with node-negative tumors 3 cm or smaller in size, treated with Breast Conservative Surgery and Endocrine Therapy, had a local recurrence rate of 10% at 10 years when radiation was omitted versus 1% among those assigned to radiotherapy. In the LUMINA trial, women 55 years of age and over with low grade Luminal A breast cancer following Breast Conserving Surgery, Endocrine Therapy and without radiotherapy, had a local recurrence rate of 2.3% at 5 years. These trials provided a new option to elderly patients who wished to avoid radiotherapy

The IDEA (Individualized Decisions for Endocrine therapy Alone) study is a prospective, multicenter cohort trial, initiated at 13 US institutions in 2015. This single-arm study was designed to explore the feasibility of omitting radiotherapy in younger postmenopausal patients with early-stage breast cancer, based on genomic assay, in addition to clinicopathologic risk factors. The IDEA study was inspired by the desire to expand treatment options for de-escalation of therapy for patients with low molecular risk early stage breast cancer, based on prospective clinical data. In this study 200 eligible patients (N=200) were enrolled. This trial included postmenopausal patients 50-69 years of age, with pT1N0 unifocal invasive breast cancer, with margins 2 mm or more after lumpectomy, whose tumors were ER-positive, PR-positive and HER2-negative, with Oncotype DX 21-gene recurrence score of 18 or less. Patients consented to at least 5 years of Endocrine Therapy after lumpectomy and omitting radiotherapy. The mean age was 62 years, mean tumor size was 10 mm and mean 21-gene recurrence score was 11. Histology was ductal in 85% and lobular in 10%, 42.5% had Grade I, 54.5% had Grade II, and 3% had Grade III tumors, respectively, and lymphovascular invasion was present in 14% of tumors. Patients with bilateral disease, a previous personal history of breast cancer, previous radiotherapy to the breast region, or a known carrier of a mutation that predisposes toward breast cancer development (including BRCA-1 and BRCA-2), were excluded. The Primary end point was the rate of locoregional recurrence, 5 years after Breast Conserving Surgery.

With a clinical follow up of at least 56 months among 186 patients, the Overall Survival (OS) and Breast Cancer-Specific Survival rates at 5 years were both 100%. The 5-year freedom from any recurrence was 99%. Crude rates of Ipsilateral Breast Events for the entire follow up period for patients age 50-59 years and age 60-69 years were 3.3% and 3.6%, respectively, and crude rates of overall recurrence were 5.0% and 3.6%, respectively. No distant recurrences were observed.

It was concluded from this study that high disease control can be accomplished at 5 years after omission of radiotherapy, in postmenopausal patients with pT1N0 unifocal invasive breast cancer with favorable biologic features. The authors added that the IDEA study is the first prospective trial to incorporate a genomic assay of low molecular risk, to identify appropriate candidates for omission of breast radiotherapy.

Omission of Radiotherapy After Breast-Conserving Surgery for Women With Breast Cancer With Low Clinical and Genomic Risk: 5-Year Outcomes of IDEA. Jagsi R, Griffith KA, Harris EE, et al. Published online December 07, 2023. DOI: 10.1200/JCO.23.02270 Journal of Clinical Oncology.

FDA Approves TRUQAP® with Fulvestrant for Advanced Breast Cancer

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SUMMARY: The FDA on November 16, 2023, approved Capivasertib (TRUQAP®) with Fulvestrant for adult patients with Hormone Receptor-positive (HR-positive), Human Epidermal growth factor Receptor 2-negative (HER2-negative) locally advanced or metastatic breast cancer with one or more PIK3CA/AKT1/PTEN-alterations, as detected by an FDA-approved test, following progression on at least one endocrine-based regimen in the metastatic setting or recurrence on or within 12 months of completing adjuvant therapy. FDA also approved the FoundationOne® CDx assay as a companion diagnostic device to identify patients with breast cancer for treatment with Capivasertib with Fulvestrant.

Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S. About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and Hormone Receptor-positive (HR-positive), HER2-negative breast cancer is the most frequently diagnosed molecular subtype. The most common subtype of metastatic breast cancer is HR-positive, HER2-negative breast cancer (65% of all metastatic breast tumors), and these patients are often treated with anti-estrogen therapy as first line treatment. However, resistance to hormonal therapy occurs in a majority of the patients, with a median Overall Survival (OS) of 36 months. With the development of Cyclin Dependent Kinases (CDK) 4/6 inhibitors, endocrine therapy plus a CDK4/6 inhibitor is the mainstay, for the management of HR-positive, HER2-negative metastatic breast cancer, as first line therapy. Even with this therapeutic combination, most patients will eventually experience disease progression due to resistance to endocrine therapy. A therapy overcoming endocrine resistance is an area of active research in the breast cancer space.

The P13K/Akt pathway is a growth-regulating cellular signaling pathway, which in many human cancers is overactivated. Inhibition of the PI3K/Akt signaling pathway leads to inhibition of cell proliferation and induction of apoptosis in tumor cells. A wide range of solid and hematological malignancies show dysregulated PI3K/AKT/mTOR/PTEN signaling due to mutations in the genes involved. Overactivation of the PI3K-AKT-PTEN signaling pathway occurs in approximately 50% of HR-positive, HER2-negative breast cancers by means of activating mutations in PIK3CA and AKT1 and inactivating alterations in PTEN. These alterations may be present at the time of cancer recurrence, and can also be acquired following previous treatment including with CDK4/6 inhibitors. Further, AKT signaling may also be activated in the absence of genetic alterations in patients with endocrine resistance.

Capivasertib is a novel, first-in-class, orally bioavailable small molecule inhibitor of the serine/threonine protein kinase AKT (protein kinase B), with potential antineoplastic activity. It is a potent, selective ATP-competitive inhibitor of all three AKT isoforms (AKT1/2/3). By targeting AKT, the key node in the PIK3/AKT signaling network, Capivasertib potentially may be used as monotherapy or combination therapy, for a variety of human cancers. In the Phase II FAKTION trial, Capivasertib in combination with Fulvestrant significantly improved Progression Free and Overall Survival as compared with Fulvestrant alone, among postmenopausal women with HR-positive advanced breast cancer, who had previously received endocrine therapy. The researchers conducted the CAPItello-291 trial to determine whether the addition of Capivasertib to Fulvestrant would improve outcomes in patients with HR-positive breast cancer whose tumors had developed resistance to an Aromatase Inhibitor and CDK4/6 inhibitor.

CAPItello-291 is a randomized, double-blind Phase III trial in which 708 adult patients with histologically confirmed HR-positive, HER2-low or negative breast cancer, whose disease has recurred or progressed during or after Aromatase Inhibitor therapy, with or without a CDK4/6 inhibitor, were enrolled. Patients were randomly assigned 1:1 to receive either the Capivasertib plus Fulvestrant (N=355) arm or the placebo plus Fulvestrant arm (N=353). Patients in the study group received Capivasertib 400 mg orally twice daily for 4 days on and 3 days off along with Fulvestrant 500 mg IM on days 1 and 15 during cycle 1, then every 4 weeks thereafter. The present dosing of Capivasertib was chosen based on tolerability and the degree of target inhibition in early phase trials. The control group received matched placebo along with Fulvestrant. Patients received therapy until disease progression or unacceptable toxicity. In this trial, patients could have received up to two prior lines of endocrine therapy and up to 1 line of chemotherapy for locally advanced or metastatic disease. Approximately 40% of tumors (N=289) had PI3K/AKT/PTEN alterations. Both treatment groups were well balanced. Stratification factors included liver metastases and prior CDK 4/6 inhibitor. The dual Primary endpoints were Progression Free Survival (PFS) in the overall patient population and in a subgroup of patients whose tumors have qualifying alterations in the PIK3CA, AKT1 or PTEN genes. Secondary endpoints included Overall Survival (OS) and Objective Response Rate (ORR).

The trial met both Primary endpoints, improving PFS in the overall patient population and in a prespecified biomarker subgroup of patients whose tumors had qualifying alterations in the AKT pathway genes. In the overall trial population, patients treated with Capivasertib plus Fulvestrant had a median PFS of 7.2 months, compared to 3.6 months in patients treated with placebo plus Fulvestrant (HR=0.60; P<0.001). This amounted to a 40% lower risk of disease progression among patients who received Capivasertib plus Fulvestrant. Among patients with AKT pathway mutations treated with Capivasertib plus Fulvestrant, the median PFS was 7.3 months versus 3.1 months in the placebo group (HR=0.50; P<0.001), reducing the risk of disease progression or death by 50%, versus placebo plus Fulvestrant. An exploratory analysis of PFS in the 313 patients whose tumors did not have a PIK3CA, AKT1 or PTEN-alteration showed a HR of 0.79, suggesting that the difference in the overall population was primarily attributed to the results seen in the population of patients whose tumors have PIK3CA, AKT1 or PTEN-alteration. The benefit from Capivasertib was consistent across key clinically relevant subgroups, including patients previously treated with CDK4/6 inhibitor and patients with liver metastases.
The Objective Response Rate in the overall trial population was 22.9% among patients treated with Capivasertib plus Fulvestrant compared with 12.2% for patients treated with placebo plus Fulvestrant, and was 28.8% and 9.7% respectively in the biomarker altered population. Although the Overall Survival data were immature at the time of the analysis, early data are encouraging and follow up is ongoing. The most frequent Grade 3 or higher toxicities occurring in 5% or more of patients were diarrhea (9.3%) and rash (12.1%). Treatment discontinuation due to adverse events was 13% among patients who received Capivasertib plus Fulvestrant versus 2.3% among patients who received placebo plus Fulvestrant.

It was concluded that a combination of Capivasertib plus Fulvestrant is a new treatment option with significantly improved Progression Free Survival, in patients who have Hormone Receptor–positive/HER2-negative advanced breast cancer, who had progressed on, or have become resistant to endocrine therapies and CDK4/6 inhibitors.

Capivasertib in Hormone Receptor–Positive Advanced Breast Cancer. Turner N, Oliveria M, Howell SJ, et al., for the CAPItello-291 Study Group. N Engl J Med 2023; 388:2058-2070.

Non-Hormonal Treatments for Menopausal Symptoms – NA Menopause Society 2023 Position Statement

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SUMMARY: It is estimated that the 50 million women will attain menopause annually. Natural menopause occurs in women between age 49-52 years. Vasomotor symptoms (VMS) manifesting as hot flashes and night sweats are the most common symptoms of menopause. These symptoms occur in up to 80% of menopausal women lasting from 7-10 years and sometimes even longer, significantly impacting their quality of life. Compared to other ethnic groups, menopausal symptoms tend to be less severe in Asian women and more severe in African American women.

Hormone Replacement Therapy remains the most effective treatment and should be considered in menopausal women younger than 60 years, within 10 years of their final menstrual periods, with no contraindications. However, the use of Hormone Replacement Therapy has declined substantially, following the Women’s Health Initiative (WHI) hormone therapy trials recommendation, not to prescribe menopausal hormone therapy for chronic disease prevention due to the complex pattern of risks and benefits, including increases in invasive breast cancer, stroke and pulmonary embolism.

Nonhormonal interventions have therefore been important considerations for symptomatic menopausal women. The North American Menopause Society convened an advisory panel of clinicians and research experts in the field of women’s health, to review and evaluate the literature published after the Position Statement of The North American Menopause Society in 2015.

This advisory panel assessed the most current and available literature to recommend or not recommend use, with the level of evidence assigned, on the basis of these categories:

• Level I: Good and consistent scientific evidence.
• Level II: Limited or inconsistent scientific evidence.
• Level III: Consensus and expert opinion

The following are the evidence-based updated guidelines:

Level I
Cognitive-Behavioral Therapy: CBT has been shown to reduce the bother and interference associated with VMS.
Clinical hypnosis: Clinical hypnosis has been shown to reduce VMS frequency and severity.
Selective Serotonin Reuptake Inhibitors (SSRIs)/ Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): SSRIs and SNRIs are associated with mild to moderate improvements in vasomotor symptoms.
SSRIs: Paroxetine 7.5 mg daily is approved by the FDA for the treatment of moderate to severe vasomotor symptoms. Paroxetine however should be avoided in women taking Tamoxifen to treat or prevent breast cancer. Other SSRIs include Citalopram and Escitalopram which have less of an effect on the CYP2D6 enzyme.
SNRIs: Venlafaxine may be a safer choice in women using Tamoxifen as coadministration of SSRIs such as Paroxetine or Fluoxetine with Tamoxifen may lead to inhibition of CYP2D6 (the enzyme that converts Tamoxifen to its most active metabolite, endoxifen).
Gabapentin: Gabapentin is approved by the FDA as an antiepileptic drug, and is often used to treat diabetic neuropathy and postherpetic neuralgia. However, several trials studying the dose of 900 mg (300 mg three times/day) show that this has improved the frequency and severity of vasomotor symptoms.
Fezolinetant (VEOZAH®): Fezolinetant is a first-in-class neurokinin B antagonist that is FDA approved for management of vasomotor symptoms. It modulates the neuronal activity in the thermoregulatory center of the brain.
Oxybutynin: Oxybutynin is an antimuscarinic, anticholinergic therapy that is used for the treatment of overactive bladder and urinary urge incontinence. Oxybutynin has been shown to reduce moderate to severe vasomotor symptoms, although in older adults, long-term use may be associated with cognitive decline
Pregabalin and Clonidine are not recommended for vasomotor symptoms

Level II-III
Weight Loss: The limited available evidence suggests that weight loss may be used to improve vasomotor symptoms for some women.
Stellate ganglion blockade: This procedure is a widely used to treat migraine and complex regional pain syndrome by injecting an anesthetic agent at the lower cervical or upper thoracic region. This blockade might help alleviate moderate to very severe vasomotor symptoms in select women. Because of the potential risks and adverse events, its potential use for vasomotor symptoms should be carefully evaluated.

The following interventions have NOT BEEN PROVEN beneficial and NOT RECOMMENDED interventions:
Paced respiration, Supplements/Herbal remedies, avoiding triggers such as alcohol, caffeine, spicy foods or hot foods, Cooling techniques, Exercise, Yoga, Mindfulness-based intervention such as meditation, Relaxation, Suvorexant, Soy foods and Soy extracts, Soy metabolite equol, Cannabinoids, Acupuncture, Calibration of neural oscillations, Chiropractic interventions, and Dietary modification.

The panel concluded that the most effective treatment for vasomotor symptoms is hormonal therapy and should be considered in menopausal women within 10 years of their final menstrual periods. For women who are not candidates for hormone therapy because of contraindications (estrogen-dependent cancers or cardiovascular disease) or personal preference, it is important for healthcare professionals to be well informed about the evidence-based nonhormone treatment options, for reducing vasomotor symptoms.

NAMS POSITION STATEMENT: The 2023 nonhormone therapy position statement of The North American Menopause Society. Menopause: The Journal of The North American Menopause Society 2023;30:573-590. DOI: 10.1097/GME.0000000000002200

Targeting ESR1 Mutations in Estrogen-Positive Advanced Breast Cancer

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Written By: Debra Patt, MD, PhD, MBA

In the golden age of oncology, many patients can now live with cancer as a chronic disease. Understanding how to optimally block cancer growth and how cancers develop mechanisms of resistance is critical to improving therapy.

For most patients with advanced breast cancer, estrogen blockade is the mainstay of early cancer treatments. Optimizing estrogen blockade in combination with other targets has dramatically improved progression-free and overall survival in patients with advanced breast cancer. Optimizing endocrine blockade in patients with ER+ advanced breast cancer is not only an effective therapy that improves outcomes, but also delays other systemic therapy, like chemotherapy, which have a toxicity profile that is typically more severe than endocrine therapy alone. By delaying chemotherapy with effective endocrine therapy, patients can enjoy longer disease-free intervals and maintain a high quality of life. While estrogen-positive breast cancer can be targeted by many estrogen-targeted therapies, resistance to aromatase inhibition through the development of ESR1 mutations is an important mechanism of resistance that contributes to cancer progression via the endocrine blockade.1

As we continue to make progress in cancer care, becoming familiar with new therapies is critical. This article will review elacestrant, approved by the Food and Drug Administration (FDA) in January 2023 for patients with estrogen receptor-positive (ER+) advanced breast cancer with ESR1 mutations after at least one line of endocrine therapy.

The superior response among patients with ESR1 mutations led to FDA approval among patients with ESR1 mutations who had received at least one line of endocrine therapy. Because ESR1 mutation status is central to FDA approval and the basis of many coverage determinations from payers, assessing ESR1 mutation status accurately is an important aspect of treatment. ESR1 mutations can develop in patients with ER+ advanced breast cancer and can change over time. In patients with treatment naïve early-stage breast cancer, de novo ESR1 mutations are relatively rare, but as patients are exposed to therapy, ESR1 mutations are acquired, making them a common mechanism of resistance in patients with metastatic disease.2 Because mutations develop over time with the evolutionary pressure of therapy, a patient’s ESR1 mutation status, when they are initially diagnosed with ER+ metastatic disease, can later change after exposure to aromatase inhibition. If analysis for ESR1 mutations is conducted early in a patient’s treatment and is found negative, resistance may emerge and only be demonstrated with subsequent molecular testing. There is evidence that blood-based serial testing may be a useful way to identify patients who are eligible for treatment.3 In January 2023, Guardant Health, through the Guardant 360 CDx, was approved by the FDA as a tool to test the blood for ESR1 mutations to assess for eligibility for elacestrant. By using sequential serologic testing, patients can have an assessment of molecular characteristics without undergoing additional biopsy. Because such a small number of patients have ESR1 mutations when they are treatment naïve, but it becomes much more likely through the course of a patient’s disease, repeat testing is the primary way to assess if ESR1 mutations have evolved over time, and can be conducted via plasma assessment.

Elacestrant works by binding estrogen receptor alpha and acting as a Selective Estrogen Receptor Down regulator (SERD), allowing degradation of the estrogen receptor. The FDA approved elacestrant in 2023 based on the reporting of the phase III EMERALD trial showing that patients with ER-positive and HER2 negative advanced breast cancer who had had one to two lines of endocrine therapy, pretreatment with a cyclin-dependent kinase 4/6 inhibitor, and not more than one line of chemotherapy, achieved a significant progression-free survival advantage when treated with elacestrant in comparison to other therapy.4 The population was further stratified as the whole population vs. just those with ESR1 mutations. In the entire population treated with elacestrant, PFS was prolonged (HR=0.70; 95% CI=0.55-0.88), and the results were more striking in those with ESR1 mutations (HR=0.55; 95% CI=0.39-0.77). In this group of pretreated patients with advanced breast cancer, ESR1 mutations were detected in 47.8% of patients. The progression-free survival of patients in the EMERALD trial was 3.8 months among patients receiving elacestrant in comparison to 1.9 months for other commonly prescribed endocrine therapies.

Elecestrant was well tolerated with treatment-related grade 3/4 adverse events in 7.2% of patients receiving elecestrant in comparison to 3.1% in patients receiving standard-of-care. Nausea was the most common side effect occurring to any extent in 35% of patients receiving elecestrant (though grade 3 was 2.5% and grade 4 was 0.9%) in comparison to 18.8% in patients who were receiving standard-of-care treatment. Other common side effects include abdominal pain, vomiting, diarrhea, constipation, elevation of liver function tests, cytopenias, hyponatremia, and fatigue. To mitigate side effects, it can help to take the medication with food, administer it at the same time each day, and use supportive anti-nausea and anti-diarrheal guidance upfront, in addition to dose reductions as appropriate.

In our modern era of cancer treatment, optimizing the use of incremental therapy can benefit patients. Making sure we consider ESR1 mutations in patients with ER+ advanced breast cancer, offer appropriate testing as patients are exposed to different treatments, and anticipate and mitigate side effects as appropriate will help us manage patients with ER+ advanced breast cancer optimally.

References
1) Brett, J.O., Spring, L.M., Bardia, A. et al. ESR1 mutation as an emerging clinical biomarker in metastatic hormone receptor-positive breast cancer. Breast Cancer Res 23, 85 (2021). https://doi.org/10.1186/s13058-021-01462-3.
2) Kinslow CJ, Tang A, Chaudhary KR, Cheng SK. Prevalence of Estrogen Receptor Alpha (ESR1) Somatic Mutations in Breast Cancer. JNCI Cancer Spectr. 2022 Sep 1;6(5):pkac060. doi: 10.1093/jncics/pkac060. PMID: 35959983; PMCID: PMC9438742.
3) Sundaresan TK, Dubash TD, Zheng Z, Bardia A, Wittner BS, Aceto N, Silva EJ, Fox DB, Liebers M, Kapur R, Iafrate J, Toner M, Maheswaran S, Haber DA. Evaluation of endocrine resistance using ESR1 genotyping of circulating tumor cells and plasma DNA. Breast Cancer Res Treat. 2021 Jul;188(1):43-52. doi: 10.1007/s10549-021-06270-z. Epub 2021 Jun 8. PMID: 34101078; PMCID: PMC8667563.
4) Bidard FC, Kaklamani VG, Neven P, Streich G, Montero AJ, Forget F, Mouret-Reynier MA, Sohn JH, Taylor D, Harnden KK, Khong H, Kocsis J, Dalenc F, Dillon PM, Babu S, Waters S, Deleu I, García Sáenz JA, Bria E, Cazzaniga M, Lu J, Aftimos P, Cortés J, Liu S, Tonini G, Laurent D, Habboubi N, Conlan MG, Bardia A. Elacestrant (oral selective estrogen receptor degrader) Versus Standard Endocrine Therapy for Estrogen Receptor-Positive, Human Epidermal Growth Factor Receptor 2-Negative Advanced Breast Cancer: Results From the Randomized Phase III EMERALD Trial. J Clin Oncol. 2022 Oct 1;40(28):3246-3256. doi: 10.1200/JCO.22.00338. Epub 2022 May 18. Erratum in: J Clin Oncol. 2023 Aug 10;41(23):3962. PMID: 35584336; PMCID: PMC9553388.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S.

Patient undergoing breast conserving surgery, often receive adjuvant breast radiation therapy to reduce the risk of local recurrence. Radiation therapy however is inconvenient, expensive and is associated with acute and late toxicities. Previously published study by Kunkler IH, et al. (Lancet Oncol. 2015;16:266-273) concluded that radiotherapy could be avoided in a subset of elderly patients with low risk breast cancer following breast conserving surgery. However, conventional clinical pathological factors have limited ability to identify breast cancer patients with low risk disease, who could avoid radiation therapy. Even though biomarker assays such as 21-gene recurrence score and the Prediction Analysis of Microarray [PAM] 50 assay are being evaluated for their usefulness in identifying patients in whom radiotherapy might be omitted, follow-up in these trials is short. Molecular defined intrinsic subtypes of breast cancer may be of help in providing additional prognostic information.

Breast cancer is heterogeneous malignancy and using global gene expression analyses, 5 breast cancer intrinsic subtypes have been established. They include Luminal A, Luminal B, HER2-enriched, Basal-like, and Normal breast-like group. Luminal A breast cancer overexpresses estrogen pathway genes and is the least proliferative, and patients have the lowest risk of recurrence with the best prognosis. In a retrospective analysis of women over age 60 years, with Luminal A, Grade 1-2, T1N0 breast cancer, treated with breast conserving surgery and endocrine therapy alone, the local recurrence rate was low (JCO 2015; 33:2035). However, the utility of combining molecular subtype (Luminal A subtype) with clinical pathological factors, to guide radiotherapy decision-making, has not been prospectively evaluated.Molecular-Subtypes-of-Breast-Cancer

LUMINA is a prospective multicenter single-arm, cohort study, in which 500 women, 55 years and older, who had undergone breast conserving surgery for breast cancer, were enrolled. Eligible patients had invasive ductal T1N0, Grade 1-2, Luminal A breast cancer, had undergone breast conserving surgery, with excision margins of at least 1 mm and sentinel lymph node biopsy, omitted radiotherapy, and had received adjuvant endocrine therapy for at least 5 years. Luminal A subtype was defined as ER 1% or more, PR more than 20%, HER2 negative and Ki67 13.25% or less. Ki67 immunohistochemistry was performed centrally in one of three Canadian laboratories using International Ki67 Working Group methods. The median patient age was 67 years, 66% had Grade 1 tumors, 88% of patients were less than 75 years, and the median tumor size was 1.1 cm. Patients were excluded if they had a lobular carcinoma (including mixed ductal-lobular carcinoma), clinical or pathological evidence of direct extension to the chest wall or skin, multifocal or multicentric disease, Grade 3 histologic features, extensive intraductal component, or evidence of lymphovascular invasion. Patients were followed every six months for the first two years and then yearly. The Primary outcome was local recurrence defined as time from enrollment to any invasive or non-invasive cancer in the ipsilateral breast. Secondary endpoints included contralateral breast cancer, Disease Free Survival, and Overall Survival.

At a median follow up of 5 years, the local recurrence rate was 2.3% and the rate of contralateral breast cancer was 1.9%. The 5-year Disease Free Survival was 89.9% and 5-year Overall Survival rate was 97.2%.

The authors concluded that among women 55 years of age and over, with low grade Luminal A breast cancer, omission of radiation therapy following breast conserving surgery and treatment with endocrine therapy alone for 5 years or more, resulted in very low rates of local recurrence at 5 years. The researchers added that approximately 30,000-40,000 women per year in North America, predominantly in the US, could avoid the morbidity, expense, and inconvenience of radiotherapy.

Omitting Radiotherapy after Breast-Conserving Surgery in Luminal A Breast Cancer. Whelan TJ, Smith S, parpia S, et al. for the LUMINA Study Investigators. N Engl J Med 2023; 389:612-619.

Late Breaking Abstract – ASCO 2023: Toripalimab Plus Chemotherapy Improves Progression Free Survival in Metastatic Triple Negative Breast Cancer

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SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S.

Triple Negative Breast Cancer (TNBC) is a heterogeneous, molecularly diverse group of breast cancers and are ER (Estrogen Receptor), PR (Progesterone Receptor) and HER2 (Human Epidermal Growth Factor Receptor-2) negative. TNBC accounts for 15-20% of invasive breast cancers, with a higher incidence noted in young patients. It is usually aggressive, and tumors tend to be high grade and patients with TNBC are at a higher risk of both local and distant recurrence. Those with metastatic disease have one of the worst prognoses of all cancers with a median Overall Survival of 13 months. The majority of patients with TNBC who develop metastatic disease do so within the first 3 years after diagnosis, whereas those without recurrence during this period of time have survival rates similar to those with ER-positive breast cancers.

Previously published studies have shown that presence of tumor-infiltrating lymphocytes was associated with clinical benefit, when treated with chemotherapy and immunotherapy, in patients with TNBC, and improved clinical benefit was observed in patients with immune-enriched molecular subtypes of metastatic TNBC. Toripalimab, a checkpoint inhibitor, is a humanized IgG4K monoclonal antibody that binds to the PD-1 receptor and blocks its interaction with ligands PD-L1 and PD-L2. It thereby reverses the PD-1 pathway-mediated inhibition of the immune response, and unleashes the tumor-specific effector T cells. Toripalimab provided significant clinical activity with a favorable safety profile in several solid tumors.

The purpose of this study is to compare the efficacy and safety of Toripalimab versus placebo, in combination with nab-Paclitaxel for metastatic or recurrent TNBC. The rationale for combining chemotherapy with immunotherapy is that cytotoxic chemotherapy releases tumor-specific antigens, and immune checkpoint inhibitors such as Toripalimab when given along with chemotherapy can enhance endogenous anticancer immunity.

TORCHLIGHT is a randomized, double-blind, placebo-controlled, multi-center, Phase III trial, in which the safety and efficacy of Toripalimab plus nab-Paclitaxel was compared with placebo plus nab-Paclitaxel in patients with Stage IV or recurrent/metastatic TNBC. In this study, 531 (N=531) eligible patients were randomly assigned 2:1 to receive Toripalimab 240mg IV on Day 1 every 3 weeks (N=353) or placebo (N=178), along with nab-Paclitaxel given at 125 mg/m2 on days 1 and 8 of each cycle. Treatment was continued until disease progression or intolerable toxicity. Patients could not have received more than one line of chemotherapy in the metastatic setting and had to be eligible for taxane monotherapy. Baseline characteristics were well balanced between the treatment groups and patients were stratified based on PD-L1 expression, Paclitaxel therapy history and line of prior therapy at enrollment. In the Toripalimab group, 200 patients had PD-L1 positive disease, whereas 100 patients in the placebo group had PD-L1-positive disease. The Primary endpoint was Progression Free Survival (PFS) assessed by a Blinded Independent Central Review (BICR), first in the PD-L1-positive population and then in the Intent-To-Treat (ITT) population. Secondary endpoints included Overall Survival (OS), Objective Response Rate (ORR), Duration of Response (DoR), Disease Control Rate and Safety.

At interim analysis, with the median follow up of 14 months, a statistically significant improvement in PFS was demonstrated with Toripalimab in the PD-L1 positive subgroup. The median PFS was 8.4 months versus 5.6 months respectively (HR=0.65; P=0.01). The PFS in the overall population showed a similar trend and was 8.4 months in the Toripalimab group and 6.9 months in the placebo group (HR=0.77; P=0.04). A descriptive Overall Survival analysis showed a trend towards improved OS with Toripalimab in the PD-L1 positive group (median OS 32.8 versus 19.5 months; HR=0.61; P=0.01). In the overall population, the median OS was 33.1 versus 23.5 months (HR=0.69, P=0.01). No new safety signals were identified.

The authors concluded that, for PD-L1 positive metastatic or recurrent Triple Negative Breast Cancer patients receiving first-line treatment, the addition of Toripalimab to nab-Paclitaxel resulted in a significant improvement in Progression Free Survival with an acceptable safety profile. Patients are being followed for the final PFS and OS analysis.

TORCHLIGHT: A randomized, double-blind, phase III trial of toripalimab versus placebo, in combination with nab-paclitaxel(nab-P) for patients with metastatic or recurrent triple-negative breast cancer (TNBC). Jiang Z, Ouyang Q, Sun T, et al. J Clin Oncol 41, 2023 (suppl 17; abstr LBA1013)

Ovarian Ablation or Suppression May Lower the Risk of Breast Cancer Recurrence

RR

SUMMARY: Breast cancer is the most common cancer among women in the US and about 1 in 8 women (12%) will develop invasive breast cancer during their lifetime. It is estimated that approximately 300,590 new cases of breast cancer will be diagnosed in 2023 and about 43,700 individuals will die of the disease, largely due to metastatic recurrence. Breast cancer is the second leading cause of cancer death in women, in the U.S. About 70% of breast tumors express Estrogen Receptors and/or Progesterone Receptors, and HR-positive/HER2-negative breast cancer is the most frequently diagnosed molecular subtype. About 90% of all breast cancers are detected at an early stage, and these patients are often cured with a combination of surgery, radiotherapy, chemotherapy, and hormone therapy.

It has been hypothesized that estrogen in breast cancer acts as a catalyst/promoter for cancer growth, by stimulating the division and proliferation of breast tissue and increasing the risk for cancer causing mutations. A recently published study (Nature 2023;618:1024–1032) suggests that estrogen might be involved in the genomic reshuffling that gave rise to cancer-gene activation in breast cancer, acting as an initiator as well.

The researchers in this study postulated that suppressing ovarian function of women with breast cancer may improve outcome by preventing estrogenic stimulation of any residual/microscopic cancer, particularly among pre-menopausal women with Estrogen Receptor (ER)-positive tumors. To further clarify this benefit, the researchers from the Early Breast Cancer Trialists’ Collaborative Group (EBCTCG) conducted a patient-level meta-analysis of 14,993 pre-menopausal women in 25 randomized trials, that compared ovarian ablation or suppression with no ovarian ablation or suppression. Primary analyses included only premenopausal women age less than 55 years, with ER-positive or unknown tumors, stratified into those who received no chemotherapy, or remained premenopausal following chemotherapy, and those whose menopausal status following chemotherapy was not ascertained.

The following observations were noted from this meta-analysis:

–Fewer breast cancer recurrences were seen overall with ovarian ablation/suppression than control (RR=0.82, P< 0.0001).

• Among women receiving no chemotherapy or remaining premenopausal after chemotherapy (N=7,213), similar benefits were seen and the reduction in recurrent breast cancer was significant with ovarian ablation/suppression than control. The breast cancer recurrence rate at 15 years was 39.3% in the control group versus 29.5% in the ovarian ablation or suppression group, with an absolute benefit of 9.8% and a Rate Ratio (RR) of 0.71 (P<0.0001).

• Breast cancer mortality and all-cause mortality in the ovarian ablation or suppression group at 15 years, were improved by 8.0% (20.9% versus 28.9%; RR 0.69, P<0.0001) and 7.2% (26.0% versus 33.1%; RR = 0.73, P< 0.0001), respectively, with no increase in deaths without recurrence (RR = 0•88, P=0.33).

• Among those women who were premenopausal before chemotherapy and whose menopausal status was uncertain after chemotherapy (N=7,786), the rate of recurrence at 15 years was 43.1% in those who received ovarian ablation/suppression and 44.4% in the control group (RR=0.91; P =0.03).

• Recurrence reductions were significantly larger among premenopausal women under 45 years, than among those 45-54 years, and did not differ significantly by tumor characteristics. Among premenopausal women under 45 years (N=4,437), the recurrence rate was 41.3% in the control group and 30.4% with ovarian ablation or suppression, representing a 15-year benefit of 10.9% and a Rate Ratio of 0.66 (P<0.00001). Among those women 45-54 years (N=2,776), the recurrence rate was 36.1% in the control group and 28.6% with ovarian ablation or suppression, suggesting a 15-year benefit of 7.5% and Rate Ratio of 0.82 (P=0.02).

• Among those taking Tamoxifen, the benefit with ovarian ablation or suppression was less, and was only 4.5% (RR = 0.80; P =0.002).

The authors concluded that ovarian ablation or suppression in pre-menopausal women less than 45 years with ER-positive breast cancer, substantially reduces the 15-year risk of recurrence and death from breast cancer, without increasing mortality from other causes.

Effects of ovarian ablation or suppression on breast cancer recurrence and survival: Patient-level meta-analysis of 14,993 pre-menopausal women in 25 randomized trials. Gray RG, Bradley R, Braybrooke J, et al. J Clin Oncol 41, 2023 (suppl 16; abstr 503)