Detection of P53 Protein in Oropharyngeal Carcinoma. Prognostic Implications

Objective: To demonstrate how the detection of p53 protein in formaldehyde-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 squamous cell carcinoma of the oropharynx tissues from 106 patients who underwent surgical therapy between 1975 and 1988 were immunostained by using M-7001 antibody (IgG class).

Results: Overexpression of p53 was observed in 46 tumors (43.4%). The detection of nuclear p53 was significantly 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 relation to overall survival (P < .001). In a multivariate analysis stratified according to grade, pathological stage, and lymph node status, nuclear p53 status was an independent predictor of overall survival (P < .001).

Conclusions: In patients with squamous cell carcinoma of the oropharynx, an accumulation of p53 in the tumor cell nuclei detected by immunohistochemical methods predicts a significantly increased risk of death, independent of tumor grade, stage, and lymph node status. The p53 overexpression appears to be a useful prognostic factor.