IMPACT OF ADJUVANT CHEMOTHERAPY AFTER RADICAL CYSTECTOMY FOR PATIENTS WITH LOCALLY ADVANCED BLADDER CANCER

(Objective) The study aimed to retrospectively evaluate the therapeutic effects of adjuvant chemotherapy (AC) in patients following radical cystectomy (RC) in locally advanced bladder cancer. (Methods) A single-center-derived database registered 227 patients diagnosed with muscle-invasive bladder cancer and treated with RC and pelvic lymphadenectomy between March 2003 and December 2021. Of these, patients diagnosed with non-organ-confined diseases were classified as either pT3-T4 or pN-positive without distant metastasis. Platinum-based AC was administered for the following categories: two courses for patients with pT3-T4 and pN-negative and three courses for those with pTany and pN-positive. The primary endpoint was the disease-free survival (DFS) and overall survival (OS) between the patients receiving and not receiving AC. (Results) Among all patients, 90 were diagnosed with non-organ-confined disease: 43 (47.8%) were treated with AC and the remaining 47 (52.2%) were left untreated. The methotrexate, vinblastine, doxorubicin, and cisplatin regimen; the gemcitabine and cisplatin regimen; and the gemcitabine and carboplatin regimen were administered to 14 (32.6%), 25 (58.1%), and 4 (9.3%) patients, respectively. With a median follow-up period of 26 months, the groups that received and did not receive AC had 2-year DFS rates of 36.3% and 25.9% (median DFS time: 15 vs. 8 months, p=0.026) and 2-year OS rates of 64.3% and 41.4% (median OS time: 38 vs. 18 months, p=0.064), respectively. In patients with pT3-T4 and pN-negative, no significant difference in the median DFS and OS between the AC and non-AC groups was observed. However, in patients with pTany and pN-positive, the DFS (median: 14 vs. 4.5 months, p=0.002) and OS (38 vs. 11.5 months, p=0.009) were longer in the AC than those in the non-AC group, respectively. The multivariate Cox regression analysis revealed that AC administration was an independent predictor for DFS (hazard ratio: 0.44, 95% confidence interval: 0.24-0.79, p=0.006). (Conclusion) Platinum-based AC following RC significantly improved DFS in pN-positive patients with locally advanced bladder cancer.