Surgery vs. radiotherapy in patients with uveal melanoma : Analysis of the SEER database using propensity score matching and weighting.

BACKGROUND: The treatment modalities for uveal melanoma (UM) include surgery and radiotherapy (RT). The utilization of RT as a strategy for organ preservation has been increasing, but the survival difference between the two aforementioned treatment modalities has not been reported.

METHODS: An observational and cohort study was performed using a propensity score with an already existing public database. Patients diagnosed with UM within the period from 2004-2013 were selected from the Surveillance, Epidemiology, and End Results (SEER) database. One-to-one matching and inverse probability of treatment weighting (IPTW) using the propensity score were used to estimate and compare survival rates.

RESULTS: Overall, 3291 patients were treated: 2503 received RT only (RT group) and 788 received surgical resection only (surgery group). The RT group had an improved crude 5‑year overall survival (OS) rate compared with the surgery group (76% vs. 60%, P < 0.001), and an improved 5‑year melanoma-specific survival (MSS) rate (89% vs. 73%, P < 0.001). Compared to the surgery group, the RT group was associated with improved OS (hazard ratio [HR] 0.52, 95% confidence interval [CI] 0.38-0.73, P < 0.001) and MSS (HR 0.48, 95% CI 0.35-0.65, P < 0.001) in the matched cohort. The survival benefit of the RT group maintained after adjustment with IPTW, both in OS and MSS.

CONCLUSIONS: To our knowledge, the present study was the first to demonstrate the survival difference between the two treatment modalities for UM using both the propensity score matching and weighting methods with the SEER database. The current study suggests that RT may provide a survival advantage over surgery in the treatment of UM.