Symptoms as an Index of Biologic Behavior in Head and Neck Cancer

Abstract

The TNM staging system for head and neck cancer is based on the morphologic description of the tumor and disregards the clinical condition of the patient. Cancer symptoms were evaluated as a biologic index of disease to improve survival estimates. The medical records of 1010 patients receiving initial cancer treatment between 1980 and 1991 were retrospectively reviewed. The mean survival duration was 62 months for the entire population. By use of SAS statistical software (SAS Institute, Cary, NC), 48 symptom variables were screened by univariate analysis, and 23 of these variables were selected for entry into a Cox proportional hazards model on the basis of survival duration. Dysphagia, otalgia, neck lump, and weight loss were identified as independent predictors of survival duration (P <0.01). A composite symptom-severity staging system was created on the basis of the 4 symptoms. Mean survival duration (95% CI) by symptom-severity stage was as follows: none, 74 months (70 to 79 months); mild, 56 months (51 to 61 months); moderate, 40 months (33 to 47 months); and severe, 31 months (22 to 41 months) (χ² = 30.8, P = 0.0001). Survival duration by TNM stage was as follows: I, 89 months (82 to 95 months); II, 71 months (65 to 78 months); III, 53 months (47 to 59 months); and IV, 42 months (37 to 47 months) (χ² = 56.2, P = 0.0001). When symptom-severity stage was entered in a proportional-hazards model along with TNM stage, comorbidity, age, and alcohol use, all 5 variables were independently predictive of survival duration (risk ratio: symptom severity 1.28, TNM 1.33, comorbidity 1.80, age 1.47, alcohol use 1.09). Appropriately defined symptom variables contain important prognostic information, which is independent of the TNM system. Therefore symptoms provide an index of biologic behavior in head and neck cancer.