Response to Neoadjuvant Systemic Therapy for Breast Cancer in BRCA Mutation Carriers and Noncarriers: A Single-Institution Experience

Abstract

Purpose To compare the pathologic complete response (pCR) rate and relapse-free survival (RFS) and overall survival (OS) after neoadjuvant systemic chemotherapy (NST) in patients with breast cancer with and without deleterious BRCA1 and BRCA2 mutations. Patients and Methods A total of 317 women who underwent BRCA genetic testing and were treated with NST for breast cancer between 1997 and 2009 were included in the study. The Kaplan-Meier product-limit method was used to estimate RFS and OS rates. Logistic regression models were fit to determine the associations between BRCA status, pCR, and survival. Results Fifty-seven (18%) and 23 (7%) patients had BRCA1 and BRCA2 mutations, respectively. Twenty-six (46%) of 57 BRCA1 carriers achieved a pCR, compared with three (13%) of 23 BRCA2 carriers and 53 (22%) of 237 BRCA noncarriers (P < .001). In the multivariate logistic model, BRCA1 status (odds ratio [OR] = 3.16; 95% CI, 1.55 to 6.42; P = .002), estrogen receptor (ER) negativity (OR = 1.96; 95% CI:1.05 to 3.65; P = .03) and concurrent trastuzumab use (OR = 4.18; 95% CI, 2.04 to 8.57; P < .001) remained as independent significant predictors for a pCR. At a median follow-up of 3.2 years, 69 patients (22%) experienced a disease recurrence or death. No significant differences were noted in survival outcomes with respect to BRCA status and type of NST received. However, among BRCA1 carriers, patients who achieved a pCR had better 5-year RFS (P = .001) and OS (P = .01) rates than patients who did not. Conclusion BRCA1 status and ER negativity are independently associated with higher pCR rates in patients with breast cancer. Overall prognosis of breast cancer in BRCA carriers is similar to sporadic breast cancers.