p53 tumor suppressor oncogene expression in squamous cell carcinoma of the hypopharynx

Background. Although abnormalities of the p53 tumor suppressor oncogene system are being detected in many human cancers, the frequency and prognostic significance of such events in squamous cell cancer of the head and neck remain unknown. Methods. Immunohistochemical studies were performed on archival tumor tissue taken from 43 patients with squamous cell carcinoma of the hypopharynx. Statistical analyses examining potential associations between p53 oncoprotein accumulation and various clinicopathologic parameters (including survival) were conducted. Results. Sixteen (37%) tumors demonstrated strong specific staining for p53. Patients whose tumors stained strongly for p53 were significantly younger, presented at a more advanced clinical disease stage, and tended to have increased expression of epidermal growth factor receptor (P = 0.056). There was no correlation between p53 expression and the incidence of multiple primary cancers, tumor grade, DNA ploidy, or percent of S-phase. Median survival times were 11.6 months and 18.0 months for the p53-positive and p53-negative groups (NS). A Cox regression analysis confirmed the lack of significance of p53 in overall survival. Conclusions. These data suggest that although abnormalities of the p53 oncoprotein are common in this cancer, this finding is of little clinical significance.