Nuclear p53 protein expression in resected hepatic metastases from colorectal cancer: an independent prognostic factor of survival.

Abstract

An association has been reported between nuclear p53 protein expression in tumour cells and a poor outcome in patients with colorectal cancer (CRC). In this study we investigated the prognostic significance of nuclear p53 protein expression in CRC liver metastases after curative hepatic resection. The study population consisted of 69 consecutive patients who underwent curative hepatic resection for metastases from CRC at our Institution between February 1987 and October 1993. Immunohistochemical expression of p53 protein was evaluated in formalin-fixed paraffin-embedded sections of CRC liver metastases using the monoclonal antibodies (MAbs) D01 and Pab 1801. The Cox proportional hazards model was used in forward stepwise regression to assess the relative influence of different prognostic factors. Forty-four (63.8%) CRC liver metastases were p53-positive. Kaplan-Meier survival curves demonstrated that patients with p53-positive metastases had a median survival of 27 months versus 93 months for patients with p53-negative metastases (P < 0.01). The 3 and 5 years survival rates were 31.5 and 21.0% in patients with p53-positive metastases and 71.8 and 53.1% in patients with p53-negative metastases. At multivariate analysis p53 protein status was the single best predictor of survival (P = 0.0079); the odds ratio of death among patients with p53-positive tumours was 2.53. Nuclear p53 protein expression in hepatic metastases from CRC is an independent prognostic factor of survival following liver resection. These findings may be of clinical importance in the selection of patients more likely to benefit from liver resection and could be used as criteria for stratification in trials on adjuvant therapy.