Cancer death from non-muscle invasive bladder cancer: Report of the Japanese Urological Association of data from the 1999-2001 registry in Japan

Objectives: Our aim was to clarify the risk factors of cancer death in order to reduce mortality from T1 bladder cancer. Methods: The Japan registration database (1999–2001) was used for the analysis. Data were collected at least 3 years after the initial diagnosis. Cause-specific survival using a Kaplan–Meier survival estimation with the log–rank method was evaluated. Univariate and multivariate analysis using the Cox proportional hazard model was also carried out. The 1997 TNM classification was used for pathological staging, and the 1973 WHO classification was used for pathological grading. Results: There were 76 cancer deaths among a total of 1919 clinical T1 cases. Regardless of the subsequent treatment strategies, non-papillary tumor appearance, non-peduncular tumor stalk, multiple tumors, a tumor size greater than 3 cm, positive urinary cytology and pathological grade 3 were found to be statistically significant in cancer death by univariate analysis. By multivariate analysis, non-papillary tumor appearance, positive urinary cytology and a tumor size greater than 3 cm were confirmed as significant risk factors. Cancer death cases were found in 47.4% of worst-grade 2 tumors, and in 67.1% of predominantly grade 1 or 2 tumors. Conclusion: Non-papillary tumor appearance, positive urinary cytology and a tumor size greater than 3 cm should be included to enable the assessment of risk criteria in cancer death from T1 bladder cancer.