Reduced expression of p21WAF1 is an indicator of malignant behaviour in anal carcinomas

Aims: p21 and p27 protein expression were examined in a comparatively large series of patients with squamous cell carcinoma of the anal canal and compared with clinical and histopathological data (tumour stage. nodal status and differentiation). Methods and results: We analysed the expression of p21 and p27 protein in 94 anal carcinomas by immunohistochemistry. Nuclear p21 and p27 staining were detected in 71% (67/94) and 75% (71/94) of the cases, respectively. There was no significant association between p27 staining and tumour stage, nodal status or overall survival. We observed that negative p21 immunoreactivity was significantly associated with poorly differentiated anal carcinomas. Furthermore. a shorter overall survival for patients with no p21 protein expression was seen. Conclusions: Our data indicate that p21 levels, but not p27 expression, may be a useful predictor of survival in patients with anal carcinomas.