Association of Increased Age With Decreased Response to Intravesical Instillation of Bacille Calmette-Gu?erin in Patients With High-Risk Non-Muscle Invasive Bladder Cancer: Retrospective Multi-Institute Results From the Japanese Urological Oncology Research Group JUOG-UC-1901-BCG

OBJECTIVE To compare the therapeutic effect of Bacille Calmette-Guerin (BCG) intravesical instillation in older and younger patients with high-risk non-muscle-invasive bladder cancer. The comparison was performed with propensity score matching (PSM) without terminating the death of the older patients using relatively large-scale retrospective data from multiple institutes in Japan.MATERIALS AND METHODS Overall, 3283 patients diagnosed with non-muscle-invasive bladder cancer treated with intravesical BCG instillation during 2000-2018 in 31 institutes were examined; 1437 and 602 patients with high-grade T1 and Tis tumors were divided into those aged >= 75 and <75 years. Multivariate analysis using the Fine-Gray competing risks regression model before PSM and survival analysis using the cumulative incidence method after PSM were performed.RESULTS In the pre-PSM series of high-grade T1 tumors, age >= 75 years was an independent prognostic fac-tor for both recurrence and progression in multivariate analysis (P = .015 and P = .013). In the pre-PSM series with Tis tumor, no variables to predict recurrence and progression was found. In the post-PSM series of 870 high-grade T1 tumors, cumulative probability of recurrence after BCG intravesical instillation were significantly higher in patients aged >= 75 years than in those aged <75 years (P = .008). The frequency of discontinuation of BCG instillation in patients aged >= 75 years with high-grade T1 and Tis was not significantly different from those in patients aged <75 years (P = .564 and P = .869).CONCLUSION The cumulative probability of recurrence after intravesical BCG instillation was significantly higher in older than in younger patients with high-grade T1 bladder cancer. UROLOGY 167: 158-164, 2022. (c) 2022 Elsevier Inc.