Relevance of the expression of bcl-2 in combination with p53 as a prognostic factor in breast cancer.

Background: Both the proto-oncogene bcl-2 and the tumour suppressor gene p53 are involved in the regulation of apoptosis.
Patients and Methods: We have investigated the prognostic value of the immunohistochemical expression of p53 and bcl-2 separately and in combination in a group of 345 breast cancer patients from one hospital with a long median follow-up of more than 10 years.
Results: Bcl-2 expression was not a prognostic factor. p53 was an independent prognostic factor for overall survival (p = 0.005) and for post-relapse survival (p = 0.006). Looking at bcl-2/p53 subgroups in the bcl-2 positive subgroup there was a large difference in both disease-free and overall survival between p53 negative and p53 positive patients. In the bcl-2 negative subgroup the p53 status was not a prognostic factor at all.
Conclusions: p53 is an independent prognostic factor for overall survival and post-relapse survival. However, p53 status is only important in the bcl-2 positive subgroup.