The influence of p53 and associated factors on the outcome of patients with oral squamous cell carcinoma

In several tumour entities the immunohistochemical detection of p53 has proved to be a predictive factor for the survival of the patients. In this study the effector waf1 and the regulator mdm2 responsible for the inactivation of p53 were also determined in 156 tissue samples of primary squamous cell carcinomas in the oral cavity and oropharynx, their lymph node metastases, and the epithelium outside the invasively growing tumour from 107 patients. In this latter epithelium there was a significant correlation between grade of dysplasia and staining for p53 (P<0.01). In the dysplastic epithelium a significant correlation between p53, waf1, and mdm2 was shown (P<0.05). Differences in the immunohistochemical staining between different blocks of the tumour tissue and also between primary tumours and their lymph node metastases were revealed in 11-44% of cases, but there was no correlation with other variables, such as formation of lymph node metastases. In contrast to the conventional tumour grading and staging, no influence of any of the variables determined on survival or recurrence-free survival could be detected. It seems that p53 and associated factors are important in the early stages of cancerogenesis but not in further tumour progression and metastatic spread.