Optimal Timing of Switching from Platinum-based Chemotherapy to Pembrolizumab for Advanced Urothelial Carcinoma Based on Real-world Data: A Multi-institutional Retrospective Study

Background/Aim: The optimal timing of switching from platinum-based chemotherapy to pembrolizumab in patients with advanced urothelial carcinoma (UC) remains unclear. Patients and Methods: Thirty-four patients who received pembrolizumab as second-line treatment after firstline platinum-based chemotherapy were retrospectively evaluated. Results: According to overall survival (OS) from pembrolizumab, there was a significant difference between <= 4 and 0.001), but not between <= 6 and 6 cycles (18.6 and 27.3 months, p=0.276). Conclusion: The optimal timing of switching from platinum-base chemotherapy to pembrolizumab in advanced UC is around six cycles.