Breast-conserving surgery in BRCA1/2 mutation carriers: are we approaching an answer?

Area of Science:

• Oncology
• Genetics
• Surgical Oncology

Background:

• Breast-conserving surgery (BCS) is a common treatment for breast cancer, but ipsilateral-breast tumor recurrence (IBTR) affects about 10% of patients.
• The optimal local therapy for BRCA-associated breast cancer remains unclear.
• This study investigates the outcomes of BCS in BRCA mutation carriers.

Purpose of the Study:

• To compare the risk of ipsilateral-breast tumor recurrence (IBTR) and contralateral breast cancer (CBC) in BRCA mutation carriers versus patients with sporadic breast cancer after BCS.
• To inform clinical decision-making regarding breast conservation in BRCA mutation carriers.

Main Methods:

• A retrospective cohort study matching 54 BRCA1/2 mutation carriers with 162 patients with sporadic breast cancer.
• All patients underwent BCS and whole breast radiotherapy.
• Follow-up was conducted for a median of 4 years, assessing cumulative incidence of IBTR and CBC.

Main Results:

• The 10-year cumulative incidence of IBTR was significantly higher in BRCA mutation carriers (27%) compared to sporadic controls (4%).
• BRCA mutation carriers also showed a higher 10-year cumulative incidence of contralateral breast cancer (CBC) (25%) versus sporadic controls (1%).
• The hazard ratio for IBTR was 3.9 (95% CI 1.1-13.8, P = 0.03).

Conclusions:

• BRCA1/2 mutation carriers have an increased risk of IBTR after BCS compared to patients with sporadic breast cancer.
• The risk of developing new primary breast cancers (CBC) also appears elevated in this group.
• These findings highlight the importance of discussing recurrence risks and risk-reducing strategies with BRCA carriers considering breast conservation.