A comparison between TNM and TANIS stage grouping for predicting prognosis of oral and oropharyngeal cancer

Abstract

Purpose: The 1987 TNM classification system modified some T and N definition but it did not change stage grouping. Consequently it has not improved the prognostic validity of the advanced stage groups. In 1993, a new stage grouping was purposed, TANIS, that seems to have a higher correlation with survival. In this report, the TNM classification and TANIS system were compared to evaluate this prognostic ability.

Patients and methods: Data from 164 patients affected by primary cancers of oropharynx or oral cavity were analyzed by means of Kaplan-Meier and Cox regression analysis.

Results: The crude survival rate at 5 years was 43.9%. Both systems showed a significant correlation with the survival rate by means of Cox regression analysis. TANIS subcategories were correlated to the mortality rate in the stage IV patients. TANIS resulted a better predictor of mortality when compared with TNM.

Conclusion: The TANIS system was able to separate the TNM stage IV patients into prognostic groups, yielding more information with respect to TNM for such a category of patients. When a comparison between TNM and TANIS was performed, it was observed that TANIS had a higher correlation with survival rate, whereas TNM did not add any information in defining the survival function.