Clinical Outcomes for BRCA Pathogenic Variant Carriers With Breast Cancer Undergoing Breast Conservation.

Area of Science:

• Oncology
• Genetics
• Surgical Oncology

Background:

• Current guidelines support breast-conserving therapy (BCT) for BRCA-associated breast cancer, yet most patients opt for mastectomy.
• Understanding BCT outcomes is crucial with expanding genetic testing and targeted therapies.

Purpose of the Study:

• To evaluate clinical outcomes in women with BRCA-associated breast cancer treated with BCT.
• To assess risks of ipsilateral and contralateral breast cancer events and bilateral mastectomy-free survival.

Main Methods:

• A single-institution cohort study of 172 women with pathogenic BRCA1/2 variants treated with BCT from 1977-2021.
• Analysis included comparison of BRCA1/2 carriers and computation of survival and cancer event risks.

Main Results:

• At median 11.8 years follow-up, 10-year overall survival was 88.5%.
• 10-year bilateral mastectomy-free survival was 70.7%, ipsilateral breast cancer risk was 12.2%, and contralateral cancer risk was 21.3%.
• Risks for BRCA1 carriers included younger diagnosis age, more advanced, hormone receptor-negative, higher-grade tumors compared to BRCA2 carriers.

Conclusions:

• Women with BRCA variants undergoing BCT face higher risks of ipsilateral and contralateral breast cancer.
• However, the majority remain free from additional cancer events and bilateral mastectomy.
• Findings aid informed decision-making for BRCA carriers considering breast conservation.