DETECTION OF P53 PROTEIN IN OROPHARYNGEAL CARCINOMA - PROGNOSTIC IMPLICATIONS

Objective: To demonstrate how the detection of p53 protein in formalde hyde-fixed, paraffin-embedded oropharyngeal carcinoma may be used as a factor in estimating prognosis. Setting: University medical centers. Design: Validation cohort. Formaldehyde-fixed, paraffin-embedded squam ous cell carcinoma of the oropharynx tissues from 106 patients who und erwent surgical therapy between 1975 and 1988 were immunostained by us ing M-7001 antibody (IgG class). Results: Overexpression of p53 was ob served in 46 tumors (43.4%). The detection of nuclear p53 was signific antly associated with an increased risk of recurrence of oropharyngeal carcinoma (P=.05). Similar results were obtained when the presence or absence of p53 in the nuclei of the tumor cells was studied in relati on to overall survival (P<.001). In a multivariate analysis stratified according to grade, pathological stage, and lymph node status, nuclea r p53 status was an independent predictor of overall survival (P<.001) . Conclusions: In patients with squamous cell carcinoma of the orophar ynx, an accumulation of p53 in the tumor cell nuclei detected by immun ohistochemical methods predicts a significantly increased risk of deat h, independent of turner grade, stage, and lymph node status. The p53 overexpression appears to be a useful prognostic factor.