Prognostic factors in squamous cell carcinoma of the oral cavity. A retrospective study of 80 cases.

A multiparameter analysis of 80 squamous cell carcinomas of the oral cavity was performed to determine the relative prognostic weight of the location of the tumor, tumor size (T), microscopic grade (G) and DNA content measured by means of flow cytometry. Tumors of the lip have an invariably favourable outcome, while at the other locations they have high rates of mortality (total 5 years of survival less than 35%). A simple statistical analysis was performed using the concepts of death sensitivity (DS), death specificity (DSp), life sensitivity (LS) and life specificity (LSp): the best measure of unfavourable outcome was represented by G3 (DS = 0.69; DSp = 1) and by DNA aneuploidy (DS = 0.76; DSp = 0.45), while the best measure of favourable outcome was represented by G1 (LS = 0.53; LSp = 0.96), T1 (LS = 0.81; LSp = 0.78) and by DNA diploidy of the tumor cells (LS = 0.45; LSp = 0.86). A survival analysis using a step by step regression model according to Cox was carried out in order to evaluate more precisely the relative importance of prognostic factors: traditional prognostic factors (histological grade = G and tumor size = T) showed a strong statistical significance, while DNA content added some additional prognostic information only if associated to the macroscopic features of the tumor.