Bcl-2 expression predicts local relapse for early-stage breast cancer receiving conserving surgery and radiotherapy

Background This study was undertaken to evaluate the prognostic significance of Bcl-2, a apoptosis-related protein, in patients with early stage breast cancer treated with breast conservation treatment (BCT). Methods After obtaining IRB approval, 504 patients with early stage breast cancer treated with BCT were entered in this study. The paraffin specimens were constructed into tissue micro-arrays with two-fold redundancy, processed and stained for Bcl-2 antibody. Bcl-2 expression was correlated with other clinicopathological parameters and clinical outcomes. Results Bcl-2 expression was identified in 116 cases (28%). Bcl-2 expression was positively correlated with both estrogen receptor and progesterone receptor status (P < 0.0001, respectively). Bcl-2 expression was associated with ipsilateral breast tumor recurrence (P = 0.0322, by log-rank test). Multivariate analysis using Cox proportional hazard model showed that Bcl-2 expression still retained significance as an independent prognostic factor for breast recurrence (P = 0.0348). Conclusions Bcl-2 expression is highly associated with an increased risk of local recurrence in patients with early stage breast cancer. Immunohistochemical staining of the primary tumor for Bcl-2 might be useful to select optimal treatment options for these patients.