Downregulation of p21/WAF1 is related to advanced and dedifferentiated laryngeal squamous cell carcinoma

Aim-To analyse p21/WAF1 expression and its relation to p53, apoptosis, cell proliferation, clinicopathological characteristics, and patient survival i n human laryngeal squamous cell carcinoma. Methods-Primary tumours for analyses were obtained from 172 patients with c omplete follow up data. All patients were treated between 1975 and 1995. Im munohistochemistry was used to evaluate the expression of p21/WAF1, bcl-2, and p53 proteins. The proliferative activity was determined using Ki67 and PCNA antibodies as well as volume corrected mitotic count (M/V index). Volu me corrected apoptotic count (AN index) was determined using an enzymatic i n situ cell death detection kit based on the TUNEL method. Results-High p21 expression was significantly related to high p53 and norma l bcl-2 expressions as well as low mitotic count. No association was notice d between p21 expression and apoptotic rate. A significant inverse correlat ion between p21 expression and advanced stage and poor differentiation was observed, but p21 expression showed no correlation with survival. Conclusions-The expression of p21 was associated with tumour stage, histopa thological grade, node status, and mitotic count, which may indicate a role for p21 in the progression of laryngeal squamous cell carcinoma.