Utilization of Neoaduvant Chemotherapy and Oncological Outcomes in Patients Undergoing Radical Cystectomy for Variant Histology Versus Pure Urothelial Bladder Cancer - A Retrospective Comparative Cohort Study

Prospective data on outcome of variant histology bladder cancer is scarce. We compared the neoadjuvant chemotherapy usage and oncological outcomes in patients undergoing radical cystectomy for variant versus pure urothelial histology bladder cancer. This was a retrospective comparative cohort study. Data was collected from the electronic database of our hospital from June 2009 to June 2018. Two hundred forty-one patients underwent radical cystectomy in the study period. Patients were divided into two groups (Group A - variant histology bladder cancer and Group B - pure urothelial histology). The primary outcome was overall survival. The secondary outcomes included recurrence free survival and complications. Of the 241 patients, 41 had variant histology. Histological variants were sarcomatoid (11), sarcoma (4), squamous cell (8), neuroendocrine (3), adenocarcinoma (8), and others (7). The median age was 59 years in both groups. The median duration of follow-up in Groups A and B was 12.5 and 24 months, respectively. NACT was given in 12 and 14% (Groups A and B). The median overall survival in Groups A and B was 24 (95% CI 14-33) and 40 months (95% CI 29-50), respectively (95% CI 25-50) (p = 0.12). The median OS trend is better with chemotherapy among both VH (NACT vs no NACT: not reached and 24 months) and UC (NACT vs no NACT: 40 and 36 months) groups. Margin positivity rate was significantly higher in Group A (12%) compared to Group B (3%) (p < 0.03). The recurrence free survival in Groups A and B was 16(CI 3-28) and 38(CI 23-52) months, respectively (p = 0.06). There was no difference in post-operative complications (Clavien Dindo) between the two groups (p = 0.59). Variant histology bladder cancers exhibit an aggressive behavior with early recurrences and a poorer overall survival compared to pure urothelial bladder cancer. Neoadjuvant chemotherapy tends to improve survival in both groups.