The optimal treatment for patients with metastatic urothelial carcinoma (mUC) patients who are unfit to receive the standard cisplatin-based chemotherapy is uncertain.

A new study published by Feld et al. in European Urology1 compared the outcomes of carboplatin-based chemotherapy versus immunotherapy. The investigators used the Flatiron Health electronic health record–derived database to find patients with mUC who started first line of treatment. The study included 1530 mUC patients who received carboplatin-based treatment and 487 mUC patients who received immunotherapy between 2011 and 2018. The investigators compared the overall survival (OS) at 12 months and 36 months between the treatment groups. They used propensity score–based inverse probability of treatment weighting (IPTW) to adjust for confounding factors that could affect clinical outcomes.

The investigators found that, at 12 months, the IPTW-adjusted OS of the immunotherapy group was lower than chemotherapy group (39.6% [95% confidence interval {CI} 34.0–45.3%] versus 46.1% [95% CI 43.4–48.8%]). On the other hand, at 36 months, the IPTW-adjusted OS of the immunotherapy group was higher than chemotherapy group (28.3% [95% CI 21.8–34.7%] vs. 13.3% [95% CI 11.1–15.5%]). Although immunotherapy showed higher hazard of death (HR 1.37, 95% CI 1.15–1.62, p < 0.001) than chemotherapy during the first 12 months, immunotherapy survival rates improved (HR 0.50, 95% CI 0.30–0.85, p= 0.01) for those who survived the one year after the first line.

This interesting real-world data show temporal variations in patterns of response to different treatments for mUC patients who are ineligible for cisplatin-based chemotherapy. Prospective randomized trials comparing carboplatin-based treatment versus immunotherapy in this patient population is needed to validate this data. Pre-specified analyses should be planned to examine whether specific patient subgroups derive more clinical benefit from chemotherapy or immunotherapy.

Written by: Bishoy M. Faltas, MD, Director of Bladder Cancer Research, Englander Institute for Precision Medicine, Weill Cornell Medicine

1. Feld, Emily, Joanna Harton, Neal J. Meropol, Blythe JS Adamson, Aaron Cohen, Ravi B. Parikh, Matthew D. Galsky et al. “Effectiveness of First-line Immune Checkpoint Blockade Versus Carboplatin-based Chemotherapy for Metastatic Urothelial Cancer.” European urology (2019).

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