PROGNOSTIC-SIGNIFICANCE OF BCL-2 EXPRESSION AND P53 NUCLEAR ACCUMULATION IN COLORECTAL ADENOCARCINOMA

The products of bcl-2 and p53 genes are involved in the regulation of apoptosis and proliferation and have been associated with prognosis in several malignancies, including colorectal adenocarcinoma. Although 2 European studies have reported a prognostic significance of Bcl-2 exp ression in colorectal adenocarcinomas, a study from the United States did not observe such an association, Therefore, we used immunohistoche mistry to evaluate the prognostic significance of Bcl-2 expression, p5 3 nuclear accumulation and their concomitant expression in 134 US pati ents with colorectal adenocarcinoma, Antigen retrieval was required fo r adequate detection of Bcl-2 expression. Fifty percent of the colorec tal tumors were classified as expressing Bcl-2, and Bcl-2 expression w as associated with longer patient survival, Antigen retrieval was not necessary for detecting nuclear accumulation of p53 by immunohistochem istry. Nuclear accumulation of p53 was detected in 44% of colorectal a denocarcinomas and was associated with decreased patient survival, Tum ors that did not express detectable levels of Bcl-2 but exhibited nucl ear accumulation of p53 were associated with the shortest patient surv ival (log rank, p = 0.001). Multivariate Cox regression analysis demon strated that Bcl-2 expression (p = 0.018), p53 nuclear accumulation (p = 0.024) and regional lymph-node metastasis (p = 0.005) were independ ent prognostic factors, Although a trend toward an inverse correlation between Bcl-2 and p53 expression was observed, the prognostic value o f Bcl-2 expression was independent of p53 status. Thus, assessment of both Bcl-2 and p53 status may be valuable in predicting the prognosis of patients with colorectal adenocarcinomas. (C) 1997 Wiley-Liss, Inc.