Prognostic Factors Affecting Postmastectomy Locoregional Recurrence in Patients with Early Breast Cancer: Are Intrinsic Subtypes Effective?

Background Many studies have investigated the association between the molecular subtypes of breast cancer and survival. The aim of this study was to identify the effects of intrinsic subtypes of breast cancer and the other clinicopathological factors on postmastectomy locoregional recurrence (LRR) in patients with early breast cancer. Methods The records of 1,195 consecutive early breast cancer patients treated with modified radical mastectomy between 2004 and 2008 were retrospectively evaluated. The effects of intrinsic subtypes of the tumor (luminal A, luminal B, HER2-overexpressing, and triple-negative) and classical clinicopathological factors on LRR were identified by univariate and multivariate statistical analyses. Results The median follow-up time was 44 months, and 16 (1.3%) patients experienced a LRR during this period. In univariate analysis, the intrinsic subtypes of breast cancer had a significant effect on LRR (p = 0.002). In multivariate analysis, only extranodal invasion and estrogen receptor (ER) status were significant predictors of LRR (p = 0.003 and 0.0001, respectively), whereas intrinsic subtypes did not reveal a significant relationship with LRR (p = 0.57; hazard ratio, 2.9; 95% confidence interval, 0.2-4.7). Conclusions The results of this study suggest that the extranodal invasion and negative ER status should potentially be considered when evaluating the risk of LRR. The predictive power of intrinsic subtypes for LRR is less than that of classical pathological indicators. This information may be useful in planning management of LRR in early breast cancer patients treated with mastectomy.