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. The American Cancer Society estimates that in the US, approximately 310,720 new cases of female breast cancer will be diagnosed in 2024, and about 42,250 individuals will die of the disease, largely due to metastatic recurrence.
The availability of multigene panel testing and next-generation sequencing is changing the landscape of cancer prevention and treatment. The necessity for genetic testing in breast cancer has gained support due to its critical role in treatment management and family risk assessment. Clinical guidelines have evolved to expand eligibility for genetic testing, yet many patients who could benefit from these tests either do not receive them or face delays in testing. This is concerning, as genetic testing informs treatment decisions, surveillance for second cancers, and risk management for relatives. This present study aimed to explore the receipt of genetic testing and communication with relatives about results in women diagnosed with early-stage breast cancer, examining patterns from initial diagnosis through survivorship, a time that is often overlooked for its importance in continued care. Specifically, it aimed to assess how these factors influence survivorship and familial risk communication over time.
The study utilized a cohort of women aged 20-79 years diagnosed with early-stage breast cancer in 2014-2015, sourced from the Georgia and Los Angeles County SEER registries. A total of 1,412 women were surveyed approximately 7 months after diagnosis and again 6 years later. The surveys collected data on genetic counseling, testing, and communication about test results. Participants were categorized based on clinical guidelines into three groups:
• Indications at Baseline: Women who had indications for genetic testing at the time of initial diagnosis.
• Indications at Follow-up Only (FUPs): Women who had indications for testing only during follow-up.
• No Indications: Women who did not have indications for genetic testing at any point.
The findings revealed that nearly half (47.4%) of the women had indications for genetic testing at some point- 28.0% at baseline and an additional 19.4% during follow-up. Among those who had an indication at baseline, 71.9% reported having undergone genetic testing. This rate was significantly higher compared to those with an indication only at follow-up (53.3%) and those with no indication (35.0%). Statistical analysis showed significant differences in testing rates between these groups (P<0.001). Importantly, racial and ethnic differences did not significantly affect the receipt of testing when controlling for age and clinical indications (P=0.239). The results for genetic counseling were similar.
Only a small fraction (3.4%) of the women pursued Direct-to-Consumer genetic testing (DTCt) for cancer.
Women who tested positive for a Pathogenic Variant (N = 62) were significantly more likely to discuss their results with most or all of their first-degree relatives compared to those with a Variant of Unknown Significance (N = 49) or a negative result (N = 419). Specifically, 62.7% of women with Pathogenic Variants communicated results to their relatives, compared to those with a Variant of Unknown Significance (38.8%) or a negative result (38.0%), (P<0.001).
In conclusion, this study underscores a significant gap in the uptake of genetic counseling and testing among women who are eligible for it based on clinical guidelines. While the proportion of women with indications for genetic testing increased over time, many women did not receive it. This gap was consistent across racial and ethnic groups, suggesting that the issue is widespread rather than confined to specific subpopulations. The study emphasizes that positive genetic results lead to increased family communication about cancer risk, whereas the uptake of DTCt remains low, reaffirming its limited role in replacing clinical-grade genetic testing in this population.
Genetic Counseling, Testing, and Family Communication Into Survivorship After Diagnosis of Breast Cancer. Katz SJ, Abrahamse P, Furgal A, et al. J Clin Oncol. 2024;doi:10.1200/JCO.24.00122.
