Survival Benefits of Adjuvant Chemotherapy for Positive Soft Tissue Surgical Margins Following Radical Cystectomy in Bladder Cancer with Extravesical Extension.

Muscle invasive bladder cancer with extravesical extension is an aggressive disease entity that requires multimodal therapy. The benefits of adjuvant chemotherapy (AC) in patients with a positive soft-tissue surgical margin (STSM), however, are relatively unknown due to exclusion of this population in randomized controlled trials of AC. We sought to define survival benefits in this patient population through our institutional bladder cancer database. Retrospective review of all patients undergoing radical cystectomy for urothelial carcinoma of the bladder from 2004-2020 with ≥pT3b disease irrespective of neoadjuvant chemotherapy (NAC) use was conducted. Progression-free survival (PFS) and overall survival (OS) estimates were obtained using the Kaplan-Meier method with log-rank test, and the Cox-proportional hazards model was used to identify predictors of improved PFS and OS. AC was defined by any chemotherapy use within 90 days of cystectomy, regardless of STSM status. 476 patients with pT3b disease or worse were identified. Median follow-up was 12.3 months. An amount of 21% of patients were treated with AC. An amount of 24% of patients had positive STSM. Median OS for patients with positive STSM was 8.4 months [95% CI 7-11.5] and 18.3 months [95% CI 15.6-20.8] ( Administration of adjuvant chemotherapy is of particular benefit in patients with positive STSM following radical cystectomy for gross extravesical disease. Positive STSM may be a representative of "early metastatic" or micrometastatic disease.