Comparative Study of the Safety and Efficacy of First-Line Cisplatin and Carboplatin Chemotherapy in Elderly Patients with Metastatic Urothelial Carcinoma

Objectives: Platinum-based chemotherapy is the standard treatment for metastatic urothelial carcinoma (mUC). However, considering elderly patients often experience comorbidities and frailty, the utility of cisplatin-based chemotherapy for elderly patients is still debatable. We conducted this study to compare the safety and efficacy of carboplatin and cisplatin in elderly patients with mUC. Methods: This retrospective study enrolled elderly patients with mUC (defined as aged ≥70 years) who underwent first-line platinum-based chemotherapy between September 2001 and October 2018. The primary endpoints were chemotherapy-related adverse events (AEs), including treatment-related hospitalization or death. The secondary outcomes were overall survival (OS) and progression-free survival calculated by Kaplan-Meier analysis. Results: In total, 108 elderly patients with mUC were enrolled and allocated into the cisplatin or carboplatin group. Patients treated with carboplatin-based chemotherapy had a significantly higher incidence of all grade ≥3 AEs (78.8 vs. 50.0%, p = 0.008) than those on cisplatin. AE-related hospitalization (47.5 vs. 19.1%, p = 0.002) and treatment-related death (17.5 vs. 4.4%, p = 0.02) were significantly increased in the carboplatin group. In the univariate analysis, the median OS in the cisplatin group was significantly increased compared with the carboplatin group (13.6 vs. 7.2 months, p = 0.045). The Cox multivariate regression model indicated that leukocytosis (HR 3.17, 95% CI 1.84-5.46, p < 0.001) and anemia (HR 2.02, 95% CI 1.11-3.65, p = 0.02) were independent prognostic factors. Conclusion: Elderly patients with mUC treated with cisplatin-based chemotherapy had better survival and safety profiles than those treated with carboplatin. Age itself was not a crucial factor in determining cisplatin eligibility.