ABSTRACT
PURPOSE: Neoadjuvant chemotherapy (NAC) has become the standard treatment for patients with locally advanced breast cancer. The purpose of this study was to evaluate prognosis according to molecular subtype and clinicopathologic factors in patients with locally advanced breast cancer treated by NAC. METHODS: We retrospectively analyzed the medical records of 91 patients with breast cancer who underwent NAC followed by surgery between January 2005 and January 2010. The patients were classified into four molecular subtype groups: luminal A, luminal B, HER2 enriched, and triple negative (TN). RESULTS: Thirty-five (38%) patients had luminal A, 13 (14%) patients luminal B, 22 (24%) patients HER2 enriched and 21 (21%) patients TN breast cancer. Patients with TN breast cancer tended to be more than 50 years of age and to have a higher histologic grade. There were statistically significant differences according to ypN stage (ypN0 vs. ypN1–3; p=0.019, 5-year disease-free survival [DFS]; p=0.005, 5-year overall survival [OS]) and lymphovascular invasion (LVI) (p=0.003, 5-year DFS; p=0.006, 5-year OS) in the univariate analysis. In the multivariate analysis, LVI was a significant factor in 5-year DFS (odds ratio 2.145, 95% confidence interval 1.064–4.324, p=0.033). There was no significant difference among molecular subtypes in DFS (p=0.161) or OS (p=0.084). CONCLUSION: LVI was associated with prognosis in patients with locally advanced breast cancer treated by NAC and surgery. However, molecular subtype had no effect on 5-year DFS or OS.