Clinical-severity staging system for oral cavity cancer: five-year survival rates

The objective of this research is to improve the classification and survival estimates for patients with oral cavity cancer by combining cancer symptom severity and comorbidity with the current TNM staging system. The study design is a retrospective medical record review that uses explicit coding criteria. The medical records of 277 patients receiving initial treatment at the Washington University Medical Center between 1980 and 1989 were reviewed. Multivariate analysis identified patient factors that significantly affected 5-year survival. These patient factors, symptom severity and comorbidity, were combined with TNM to create a composite clinical-severity staging system. The overall 5-year survival rate was 46% (128/277). Survival rates by TNM stage were as follows: stage I, 72% (36/50); II, 54% (45/84); III, 37% (24/65); and IV, 29% (23/78) (chi2 = 25.27, P = 0.001). When patients were grouped according to the clinical-severity staging system, survival rates were as follows: stage I, 77% (33/43); II, 56% (45/80); III, 42% (43/103); and IV, 14% (7/51) (chi2 = 40.62, P = 0.001). Survival estimates can be improved by adding carefully studied and suitably defined patient variables to the TNM system. The current TNM staging system for oral cavity cancer is based solely on the morphologic description of the tumor and disregards the clinical condition of the patient. Patient factors, such as cancer symptom severity and comorbidity, have a significant impact on survival. Continued exclusion of patient factors leads to imprecision in prognostic estimates and hinders interpretation of clinical studies.