P53 OVEREXPRESSION CORRELATES WITH PROLIFERATIVE ACTIVITY AND PROGNOSIS IN CARCINOMAS OF THE PYRIFORM SINUS

p53 overexpression and proliferative activity were investigated in 28 squamous cell carcinomas of the pyriform sinus of the hypopharynx prior to therapy, using DO1 and MIB-1 monoclonal antibodies in routinely processed biopsies. MIB-1 scores were associated with tumour histological grade (35.4% for grade 3 versus 23.8% for grade 2 cases; p=0.008) and survival (the median of survival was 23 months for cases with MIB-1 scores less than or equal to 33.8% but 11 months only for cases with MIB-1 scores >33.8%; p<0.001). p53 scores were associated with tumour histological grade (56.5% for grade 3 versus 37.1% for grade 2 cases; p=0.02) and survival (median of survival 20 months for cases with p53 scores less than or equal to 56.2% versus 11 months for cases with p53 scores >56.2%; p=0.002). Tumour histological grade was also correlated with prognosis (median of survival 50 months for grade 2 versus 14 months for grade 3 cases; p=0.03). In the multivariate analysis, only MIB-1 (p=0.001) and p53 scores (p=0.003) had an independent prognostic significance. A linear relationship between p53 and MIB-1 scores was observed (r=0.54; p=0.012). With the limitation due to the small number of cases, our findings indicate that p53 overexpression correlates with proliferative activity and survival in squamous cell carcinomas of the pyriform sinus, and suggest the use of p53 and MIB-1 immunostainings in the pretherapeutic assessment of the tumour aggressiveness.