Status of Bcl-2 expression and Its Relationship to the Other Prognostic Factors in Breast Cancer

Roh, Gun Young; Shin, Dong Ha; Park, Yong Lae; Shin, Jun Ho; Kim, Heung Dae; Kim, Yong Sin; Han, Won Kon; Keum, Joo Seob; Kim, Myung Sook; Kong, Gu; Kim, Myung Suk

Abstract

PURPOSE
There are several well-established prognostic factors to predict the course of breast cancer. Recently, a new category of genes that control the process of programmed cell death, also called apoptosis, has been identified. It includes the bcl-2 proto-oncogene which actively blocks apoptosis. The purpose of this retrospective study is to investigate the relationship between Bcl-2 protein expression in primary breast cancers and other markers of prognostic value.
MATERIALS AND METHODS
We analyzed 43 cases of invasive ductal carcinoma of breast cancer, which were consecutively operated in the period from January 1990 to December 1994. Analysis of Bcl-2 protein, ER and PgR expression was carried out using immunohistochemistry on the paraffin-embedded tissue section. The following indices were measured.; size of the tumor, number of axillary metastasis, histological grade, menopausal status, ER, PgR, and Bcl-2 status.
RESULTS
Expression of the bcl-2 proto-oncogene was found in 28 cases of 43 patients (65.1%). No relationship could be observed between Bcl-2 status and tumor grade, TNM staging and menopausal status. A strong positive relationship was demonstrated between Bcl-2 immunoreactivity and ER status (P 0.001) and PgR status (P=0.014). A favorable prognostic value was demonstrated for Bcl-2 expression on overall survival (P=0.0427), but no prognostic value was demonstrated on disease-free survival (P=0.1587).
CONCLUSION
Our results suggest that the Bcl-2 expression may be a favorable prognostic marker and its important role may be a modulator of response to adjuvant therapy in breast cancer.