Expression of bcl-2 in invasive and in situ carcinoma of the uterine cervix

Abstract

Objective: The oncoprotein bcl-2 inhibits apoptosis. The purpose of this study was to assess the expression of bcl-2 in human cervical carcinoma and to correlate this with clinicopathologic parameters.

Study design: Immunohistochemical staining for bcl-2 protein (MoAB clone 124) was performed on operative tissue specimens from 22 patients with carcinoma in situ of the cervix and from 137 patients with invasive cervical carcinoma (International Federation of Gynecology and Obstetrics stages I to IV). The immunoreactivity of bcl-2 was scored as positive (> or = 5% staining cells) or negative (< 5% staining cells).

Results: Eighty-two percent of in situ carcinomas and 61% of invasive cervical carcinomas were bcl-2 positive. Expression of bcl-2 was correlated to tumor stage (p < 0.001) and to presence of vascular (p < 0.005) or lymphatic tumor (p < 0.023) permeation. In univariate analysis there was a strong relationship between bcl-2 expression and overall survival (p < 0.001). In multivariate analysis bcl-2 expression (p < 0.001), International Federation of Gynecology and Obstetrics stage (p = 0.011), and presence of lymphatic permeation (p = 0.014) proved to be independent prognostic factors.

Conclusions: Expression of bcl-2 is lost during tumor progression and is a strong prognostic parameter, suggesting that the regulation of apoptosis plays an important role in the behavior of cervical carcinomas. Better understanding of the mechanisms involved may lead to improved medical treatment strategies.