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Bcl-2 is a tumorigenic protein that is expressed in 25% to 50% of breast cancers. Although its expression has been widely accepted as a favorable prognostic marker, its protective mechanism of action remains unclear. "Triple-negative" tumors are an aggressive subgroup known to carry a poor prognosis. Studies documenting prognostic significance of Bcl-2 expression in triple-negative in comparison to non-triple-negative breast cancers are limited. Bcl-2 expression was correlated with tumor size, grade, histologic type, lymphovascular invasion, lymph node status, patients' overall survival, estrogen receptor, progesterone receptor, Her-2, p53, and epidermal growth factor receptor in 124 triple-negative and 458 non-triple-negative tumors. There were significant differences between triple-negative and non-triple-negative tumors in their relationship to Bcl-2 expression (81% versus 29%, respectively) and tumor aggression. As previously reported, in non-triple-negative tumors, Bcl-2 positivity correlated with less aggressive tumors (94% of grade I tumors were Bcl-2+ versus 62% of grade III tumors, P < .011) and overall survival (P = .008). However, the opposite was true in patients with triple-negative tumors, where Bcl-2 positivity was associated with poorer survival (P = .64). In triple-negative tumors, Bcl-2 positivity was not associated with any of the aforementioned parameters except for a lower incidence of lymph node metastasis. Moreover, by Cox regression analysis of all variables, in patients with triple-negative tumors, lymphovascular invasion (P = .009) and Bcl-2 expression (P = .028) were predictors of poor survival. In conclusion, there are major clinicopathologic differences between breast cancer phenotypes. Our results establish the value of using Bcl-2 in prognostic stratification of patients and its potential therapeutic implications in selecting patients for treatment.

Several studies have documented the prognostic significance of cell proliferation in breast cancer and its positive relationship with tumor grade, size, mitotic activity, hormonal and Her-2 status, and tumor progression. The Ki-67 antigen provides an accurate measure of the growth fraction of a tumor. Ki-67 expression in 103 primary breast carcinomas and their corresponding axillary lymph node metastases was correlated with age, tumor grade, size, estrogen receptor (ER), progesterone receptor (PgR), p53, epidermal growth factor receptor (EGFR), Bcl-2, Her-2 status, and patients' overall survival. Median Ki-67 expression in primary and metastatic tumors was 20% and 15%, respectively. Although there was no difference in overall survival (P = .65, log-rank test) between primary tumors with less than or at least 10% Ki-67 expression, there was significantly better overall survival when Ki-67 expression in lymph nodes was less than 10% (P = .040). For patients whose primary tumors exhibited Ki-67 expression less than 10%, most of their metastatic lesions had a similar low Ki-67; these patients had a favorable outcome. A small subgroup was noted to have a nodal Ki-67 of 10% or more and worse survival (P = .047). For patients whose primary tumors had a Ki-67 of 10% or more, most of their metastatic lesions had similar high Ki-67 values; however, a group of 12 patients had lymph node Ki-67 less than 10% and had a better overall survival (P = .092). Our results showed that measurement of Ki-67 in lymph node is superior to its evaluation in primary tumors. Identification of subgroups of patients in whom Ki-67 expression in lymph nodes differs from expression in primary tumor may assist in the selection of therapeutic options.