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.