A PROGNOSTIC INDEX FOR NASOPHARYNGEAL CARCINOMA - MULTIVARIATE-ANALYSIS OF PATIENTS TREATED BY RADIOTHERAPY

A group of 187 patients who completed a course of radiotherapy for carcinoma of the nasopharynx during a 20 years period (1962-1982), was analyzed by univariate and multivariate statistical techniques. The clinical features were correlated with survival rates. Five factors affecting survival were examined: T-stage, N-stage, age, sex and histology (tumor differentiation). By multivariate techniques, tumor (T) and lymph node (N) status were shown to be independent prognostic covariates. According to T and N status a prognostic index was derived and two prognostic subgroups of patients were identified (good and poor prognosis subsets). The median survival time in the good prognosis group ranged from 55 (T2, NO and T1, N1) to 135 (T1, N0) months, while the median survival time in the poor prognosis group ranged from 10.8 (T4, N3) to 37.8 (T3, N0) months. In the same groups the prognostic index (I) ranged from 0.2329 (T1, N0) to 0.5684 (T1, N1) in the good prognosis subset and from 0.6987 (T3, N0) to 1.9381 (T4, N3) in the poor prognosis subset. This statistical approach can be a serious attempt to define groups of patients with carcinoma of the nasopharynx for whom conventional therapy is less successful and for whom new procedures may be considered.