Comparison of the University of Pittsburgh staging system and the eighth edition of the American Joint Committee on Cancer TNM classification for the prognostic evaluation of external auditory canal cancer

The purpose was to compare survival differences between patients with external auditory canal (EAC) cancer treated according to the University of Pittsburgh modified TNM staging system and those treated in accordance with the 8th edition of the American Joint Committee on Cancer (AJCC) staging manual on the TNM staging system for cutaneous cancers of the head and neck.We performed a retrospective, single-institution review of 60 patients with EAC cancer treated with curative intent between September 2002 and March 2018. Survival outcomes were measured on the basis of the two staging systems.The C-index values for the overall survival (OS) rate revealed that the University of Pittsburgh staging system had higher prognostic accuracy than the 8th edition of the AJCC staging system. Univariable and multivariable analysis showed that T classification according to the University of Pittsburgh staging system was an independent predictor of the OS rate (hazard ratio 5.25; 95% confidence interval 1.38-24.9; P = 0.015). Meanwhile, the AJCC staging system could not differentiate T2 from T3-4 cancers.The University of Pittsburgh staging system for patients with EAC cancer is a valuable tool for use in clinical decision-making and predicting survival outcome.