Researchers from 13 institutions in South Korea investigated the long-term oncologic outcomes of breast-conserving treatment (BCT) compared with mastectomy in patients with breast cancer carrying BRCA1 or BRCA2 pathogenic variants. The study included 575 South Korean female patients treated between January 2008 and December 2015, with a median follow-up of 8.3 years. Among the 575 patients, 43.7% had triple-negative breast cancer and 58.8% carried BRCA1 pathogenic variants.
To reduce potential selection bias, the researchers used 1:1 propensity score–matching based on factors such as age, tumor size, lymph node metastasis, histologic grade, tumor subtype, and chemotherapy status. After matching, 159 patients were included in each group. Janghee Lee, MD, PhD, of the Department of Surgery, Ewha Womans University Mokdong Hospital, Ewha Womans University College of Medicine, Seoul, Republic of Korea, and colleagues evaluated oncologic outcomes, including locoregional recurrence–free survival, distant recurrence–free survival, recurrence-free survival (RFS), and overall survival (OS). Results of the analysis were published in JAMA Network Open.
There were no significant differences between the BCT and mastectomy groups for any oncologic outcome. Fve-year RFS and OS across the entire cohort were 91.1% and 96.6%, respectively. Eight patients experienced locoregional recurrence in each group. Distant recurrence occurred in 10 patients (6.4%) in the BCT group and in 16 patients (10.3%) in the mastectomy group. Overall survival events were also comparable between the two surgical approaches.
Contralateral breast cancer developed in 14.2% of patients who did not undergo prophylactic contralateral mastectomy, with similar incidence in both the BCT and mastectomy groups.
These findings suggest that BCT is a safe and effective surgical option for patients with breast cancer and BRCA1 or BRCA2 pathogenic variants. The researchers concluded that BCT offers comparable long-term oncologic outcomes to mastectomy and can be considered a viable treatment option with appropriate surveillance. They recommend further prospective studies to confirm these findings in broader and more diverse patient populations.
The researchers reported no conflicts of interest.
Source: JAMA Network Open