Role of Neoadjuvant Chemotherapy in Squamous Variant Histology in Urothelial Bladder Cancer: Does Presence and Percentage Matter?

This study sought to assess the role of neoadjuvant chemotherapy in the management of urothelial carcinoma of the bladder with squamous variant histology. Patients were stratified by both receipt of neoadjuvant chemotherapy and by the percentage of squamous variant histology in the transurethral resection specimen. Overall, we found favorable results in patients with < 50% involvement by squamous variant histology who received neoadjuvant chemotherapy. Background: The purpose of this study was to evaluate the effect of neoadjuvant chemotherapy (NACT) on squamous variant (SV) bladder cancer by investigating patients presenting with SV histology at the time of transurethral resection (TUR), stratified by their receipt of NACT. Materials and Methods: The records of 71 patients with muscle-invasive bladder cancer and SV in the TUR specimen who underwent cystectomy between 2008 and 2018 were reviewed. Our primary outcome was pathologic response at time of cystectomy. Secondary outcomes included recurrence-free survival and overall survival stratified by receipt of NACT. A subgroup analysis was then conducted on the patients with defined SV% on TUR stratified by % involvement ( 50% SV vs. 50% SV). Results: The median age of the NACT and no-NACT groups was 60.2 and 70 years, respectively (P = .003). The complete response rate at cystectomy was 60% versus 13.7% for the NACT and no-NACT groups, respectively (P < .001). The non-organ-confined disease rate at time of radical cystectomy was 35% for the NACT group and 68.6% for the no-NACT group (P = .01). The NACT group had fewer recurrences than the no-NACT group (10% vs 47.1%; P = .003). In the subgroup analysis, the lower rate of non-organ-confined disease persisted for the patients who underwent NACT at the lower SV percentage but failed to remain significant at greater percentage involvement. This was also true for overall survival. Conclusions: The effect of NACT in variant histology bladder cancer is variable. In patients with SV, these results favor the recommendation in favor of NACT administration, particularly when the primary tumor has < 50% involvement by the variant histology.