Independent predictors of response and disease‐free survival in oral cancer treated with radical radiation therapy

Abstract

There have been no reports concerning the independent predictors of response and disease‐free survival (DFS) in oral cancer in India, where the highest incidence is reported. The authors analyzed the outcome of radical radiation therapy of 378 patients with oral cancer and found that the complete response rate within 6 months of completion of treatment was 45% and the 5‐year DFS was 34% (95% confidence interval 29% to 39%). Regional lymph node involvement (P < 0.001), histologic type (P < 0.01), and the intraoral site of lesion (P < 0.025) were identified as independent predictors of response when adjusted in a forward stepwise logistic regression analysis. The Cox proportional hazards regression analysis revealed that regional lymph node involvement (P < 0.001) and histologic type (P < 0.05) were independent prognostic factors for DFS. Patients with fixed regional lymph node involvement demonstrated a relative risk (RR) of 2.4 compared with those with NO disease. Patients with well‐differentiated squamous carcinoma had an RR of 2, and those with other histologic types (other than verrucous carcinoma) had an RR of 1.5. Copyright © 1992 American Cancer Society