Breast-conserving therapy is safe both within BRCA1/2 mutation carriers and noncarriers with breast cancer in the Chinese population

Abstract

Background: BRCA1/2 mutation is associated with a high risk of breast cancer, which may preclude breast cancer patients with BRCA1/2 mutation from breast-conserving therapy (BCT) [breast-conserving surgery (BCS), followed by radiotherapy, BCT]. It is debatable whether BCT could be a rational choice for Chinese breast cancer patients with a BRCA1/2 mutation. Methods: The study comprised a cohort of women with invasive breast cancer either receiving BCT or mastectomy following the criteria for the germline BRCA1/2 mutation test. Germline DNA for BRCA1/2 testing was derived from blood samples. Survival analyses were performed. The correlations were analyzed between survival and distinct types of surgery. To compare the survival between different surgical management, Kaplan-Meier univariate analysis and multivariate Cox regression was used. Results: In BRCA1/2 mutation carriers (N=176) and noncarriers (N=293), 25% and 27.3% of the patients received BCT, respectively (P=0.675). Patients receiving mastectomy (without radiotherapy or followed by radiotherapy) have larger tumor size (P<0.05 both in BRCA1/2 mutation carriers and noncarriers), prognostically worse tumor characteristics including significantly more advanced TNM stage (P=0.017 and P<0.0001 respectively) and more positive lymph nodes (P=0.008 and P<0.0001, respectively) both in BRCA1/2 mutation carriers and noncarriers. Still, more often received systemic therapy has also been observed. After adjustment for clinical-pathological characteristics and systemic treatment, patients who received BCT had a similar breast cancer disease-free survival compared with patients who received mastectomy, both in BRCA1/2 mutation carriers and noncarriers [HRBRCA1/2 =1.17, confidence interval (CI): 0.57-2.39, P=0.68; HRnoncarriers =0.91, CI: 0.47-1.77, P=0.79, respectively). The recurrence free survival after BCT did not differ from mastectomy in BRCA1/2 mutation carriers [BCT, 5-year cumulative recurrence-free survival (RFS) =0.95, CI: 0.89-1.00; mastectomy, 5-year cumulative RFS =0.93, CI: 0.85-1.00], even better for BCT in noncarriers (BCT, 5-year cumulative RFS =0.67, CI: 0.42-0.89; mastectomy, 5-year cumulative RFS =0.83, CI: 0.71-0.95). Conclusions: Thus, BCT may be a safe and rational choice for Chinese female breast cancer patients with a BRCA1/2 mutation. However, tumor size, the TNM stage, the number of positive lymph nodes, might be taken into consideration when choosing surgical management.