Objective: To analyze whether the local-regional surgical treatments (breast-conserving therapy, mastectomy) resulted in different overall survival, distant metastasis-free survival, and locoregional recurrence-free survival rates for the various molecular breast cancer subtypes.
Summary background data: Molecular gene expression profiling has been proposed as a new classification and prognostication system for breast cancer. Current recommendation for local-regional treatment of breast cancer is based on traditional clinicopathologic variables.
Methods: Retrospective analysis of 372 breast cancer cases with assessable immunohistochemical data for ER, PR, and Her-2/neu receptor status, diagnosed from 1998 to 2005. Molecular subtypes analyzed were luminal A, luminal B, basal like, and Her-2/neu.
Results: No substantial difference was noted in overall survival, and locoregional recurrence rate between the local-regional treatment modalities as a function of the molecular breast cancer subtypes. The basal cell-like subtype was an independent predictor of a poorer overall survival (hazard ratio [HR] = 2.52, 95% confidence interval [CI] 1.28-4.97, P < 0.01) and a shorter distant metastasis-free survival time (HR = 3.61, 95% CI 1.27-10.2, P < 0.01), and showed a tendency toward statistical significance as an independent predictor of locoregional recurrence (HR = 3.57, 95% CI 0.93-13.6, P = 0.06).
Conclusions: The basal cell-like subtype is associated with a worse prognosis, a higher incidence of distant metastasis, and may be more prone to local recurrence when managed with breast-conserving therapy.