Purpose: To investigate the prognostic significance of p53 expression and proliferation markers in primary laryngeal squamous cell carcinoma.
Patients and methods: Primary tumors for analyses were obtained from 103 patients, with complete follow-up data. All patients were treated between the years 1975 and 1990. The expression of p53 was analyzed with monoclonal D07 antibody and proliferative activity with Ki-67 (MIB-1) and PCNA (monoclonal 19A2) antibodies. Volume corrected mitotic (M/V) index and histological grade were determined in hematoxylin and cosin-stained slides.
Results: Sixty-eight percent of the tumors overexpressed p53. During a median follow-up of 62 months, 41 (40%) of patients relapsed. In univariate analysis site of the primary tumor, stage, p53 expression, histologic grade, and M/V index were significant predictors of disease-free survival. In multivariate analysis, only M/V index was a statistically significant predictor of disease-free survival. Overall survival was significantly better for those overexpressing p53 (10-year cumulative survival rate 68% v 44%, P = .004). In multivariate analysis, M/ V index (P = .02), p53 (P = .02), and stage (P = .007) were statistically significant predictors of overall survival. When this analysis includes stratification according to the type of treatment received, M/V index (P = .007), stage (P = .0002), and p53 (P = .006) were even more significant predictors of overall survival. No association between p53 status and proliferative activity was found.
Conclusion: Overexpression of p53 is associated with favorable disease-free and overall survival in laryngeal squamous cell carcinoma. It may also have an independent prognostic value in laryngeal cancer. M/V index, p53 overexpression, and stage predict with significant accuracy the 10-year overall survival.