BCL-2 PROTEIN EXPRESSION IN BREAST-CANCER AND ITS RELATIONSHIP TO PROGNOSIS

The expression of bcl-2 protein was studied in invasive breast cancer by immunohistochemistry. Fourty-six (56.8%) bcl-2 protein-positive tum ors were found in 81 breast cancers. There was no significant correlat ion between the bcl-2 protein immunoreactivity and histologic type, pr imary tumor status, or lymph node metastasis. However, a strong positi ve relationship was demonstrated between bcl-2 immunoreactivity and es trogen receptor status. The 5-year survival rate and disease-free surv ival rates were 73.7% and 71.1% of patients with bcl-2-positive tumors , and 62.5% and 58.0% of those with bcl-2-negative tumors; these diffe rences between the two groups of patients wete significant (p<0.05). I n multivariate analysis using Cox regression model, bcl-2 immunoreacti vity emerged as an independent prognostic indicator in breast cancer p atients.