Comparison of full-dose gemcitabine/cisplatin, dose-reduced gemcitabine/cisplatin, and gemcitabine/carboplatin in real-world patients with advanced urothelial carcinoma

Background: While gemcitabine/cisplatin (GC) is the gold standard regimen for patients with advanced urothelial carcinoma (aUC), either dose-reduced GC or gemcitabine/carboplatin (GCa) is an alternative option for “cisplatin-unfit” patients. However, few studies have compared outcomes with these commonly used regimens in the real-world setting. Methods: We retrospectively reviewed patients with aUC who received full-dose GC, dose-reduced GC, or GCa as first-line salvage chemotherapy at two university hospitals between 2016 and 2020. Progression-free survival, cancer-specific survival, and overall survival, as well as best overall response and adverse event profiles, were compared among these three regimens. Results: Of 105 patients, 41, 27, and 37 patients received full-dose GC, dose-reduced GC, and GCa, respectively. Significant differences were noted in the patients’ baseline age, primary site, and renal function among the three regimens. Sixty-nine (65.7%) patients died during a median follow-up period of 14 months. There was no significant difference among the three regimens for all survival outcomes and best overall response. However, the complete response rate of dose-reduced GC (2/27, 7.4%) appeared inferior to that of full-dose GC (9/41, 22.0%) or GCa (6/37, 16.2%). Regarding adverse event profiles, no significant difference was observed among the three regimens, except for significantly fewer cases with elevated alanine aminotransferase in the GCa group compared with the other groups. Conclusions: This study compared the oncological and toxicological outcomes of full-dose GC, dose-reduced GC, and GCa in real-world patients with aUC. Unlike in the clinical trial setting, there were almost no significant differences among the three regimens.