Despite Equivalent Outcomes, Men Receive Neoadjuvant Chemotherapy Less Often Than Women for Lymph Node-Positive Breast Cancer

Background Neoadjuvant chemotherapy (NAC) downstages breast cancer and provides prognostic information. Males with breast cancer are known to receive less treatment overall and have poorer outcomes relative to females. We hypothesized that males would be less likely to receive NAC. Patients and methods Patients with a primary diagnosis of cN1–3 breast cancer were identified in the National Cancer Database (2004–2016). Multivariable logistic regression determined the association between NAC utilization and sex, and the relationship between sex and NAC response, controlling for demographic and tumor factors. Overall survival was analyzed using a multivariable Cox model. Results In total, 196,027 patients (194,010 females, 2017 males) met inclusion criteria. A significantly greater proportion of males underwent mastectomy (80% vs. 60%, P < 0.001), and axillary lymph node dissection (76% vs. 74%, P = 0.022). Overall fewer men received chemotherapy than women (73% vs. 84%, P < 0.001); men also received NAC at a significantly lower rate (26% men vs. 45% women, P < 0.001). After accounting for demographic and oncologic factors including hormone receptor (HR) subtype, females remained more likely to undergo NAC (OR 1.84, P < 0.001). On multivariable analysis, sex was not associated with pathologic response or overall survival after NAC. Conclusions Although oncologic outcomes after NAC were similar, males with node-positive breast cancer received less NAC and more aggressive surgery than females. These data suggest men achieve outcomes comparable to women with cN1–3 disease, and NAC should be used in appropriate male patients to downstage the breast and axilla.