External validation of <scp>E</scp>uropean <scp>O</scp>rganization for <scp>R</scp>esearch and <scp>T</scp>reatment of <scp>C</scp>ancer and <scp>S</scp>panish <scp>U</scp>rological <scp>C</scp>lub for <scp>O</scp>ncological <scp>T</scp>reatment scoring models to predict recurrence and progression in <scp>J</scp>apanese patients with non‐muscle invasive bladder cancer treated with bacillus <scp>C</scp>almette–<scp>G</scp>uérin

Abstract

OBJECTIVE: To validate two prediction models (European Organization for Research and Treatment of Cancer and Spanish Urological Club for Oncological Treatment) for recurrence and progression of non-muscle invasive bladder cancer in Japanese patients who underwent bacillus Calmette-Guérin instillation therapy. METHODS: From March 1985 to April 2007, data were analyzed from 366 patients who underwent transurethral resection of bladder tumor followed by bacillus Calmette-Guérin instillation therapy. The ability of two scoring models to predict recurrence and progression was assessed by concordance index. RESULTS: For recurrence probability, the concordance index of the European Organization for Research and Treatment of Cancer and Spanish Urological Club for Oncological Treatment models was 0.514 and 0.576, respectively, which was lower than that (0.604) of a selected single prognostic factor (age) by our multivariate analysis. For progression probability, the concordance index of European Organization for Research and Treatment of Cancer and Spanish Urological Club for Oncological Treatment models was 0.693 and 0.764, respectively, which was higher than that (0.633) of a selected single factor (T stage) by our multivariate analysis. The Spanish Urological Club for Oncological Treatment scoring system resulted in better stratification of tumor recurrence and progression when compared with the European Organization for Research and Treatment of Cancer model, probably because more patients underwent bacillus Calmette-Guérin treatment in the Spanish Urological Club for Oncological Treatment cohort than in the European Organization for Research and Treatment of Cancer cohort. CONCLUSIONS: The Spanish Urological Club for Oncological Treatment scoring system is a good predictor of tumor recurrence and progression in Japanese patients who underwent bacillus Calmette-Guérin immunotherapy. A large prospective study is warranted to confirm the efficacy of this system.