Tumor Grade Improves the Prognostic Ability of American Joint Committee on Cancer Stage in Patients With Penile Carcinoma

Purpose: Penile cancer is rare. Thus, predicting cancer specific mortality may be difficult. We devised an accurate and yet easily applicable predictive rule that compares favorably with 2 previous models (73.8% and 74.7% accuracy, respectively). Materials and Methods: We identified patients treated with primary tumor excision for all stages of penile squamous cell carcinoma between 1998 and 2006. Disease stage definitions using Surveillance, Epidemiology and End Results stage, American Joint Committee on Cancer stage and TNM classification, and tumor grade were used to predict cancer specific mortality. Predictive accuracy estimates were compared using the DeLong method for related AUCs. Results: Surveillance, Epidemiology and End Results stage alone (1 predictor variable) was least accurate (74.5%). American Joint Committee on Cancer stage with tumor grade (2 predictor variables) was the most simple and most accurate (80.9%, p <0.001). A benefit similar to that of American Joint Committee on Cancer stage with tumor grade was seen for TNM classification and TG (80.7%, p = 0.8). However, this rule (4 predictor variables) was more complex than American Joint Committee on Cancer stage and tumor grade. Conclusions: American Joint Committee on Cancer stage combined with tumor grade is the simplest, most accurate cancer specific mortality prediction rule after primary tumor excision for penile squamous cell carcinoma. This method is also more accurate than 2 previous cancer specific mortality prediction rules.