Survival in patients with unresectable melanoma: To infinity and beyond?

e21504 Background: The introduction of checkpoint inhibitors and targeted treatment has led to significant improvements in prognosis for melanoma patients over the last years. We aimed to evaluate the survival per year of diagnosis. Methods: All systemically treated patients diagnosed with advanced melanoma from 2013 to 2021 were included from the nationwide Dutch Melanoma Treatment Registry. Baseline characteristics, overall survival (OS), and melanoma-specific survival (MSS) were compared between the different years of diagnosis of unresectable melanoma. Results: In total, 6324 patients were included. Over the years, the age at start of treatment gradually increased. Patients treated in 2020 and 2021 more often had an Eastern Cooperative Oncology Group Performance Status (ECOG PS) ≥2 and synchronous metastatic disease (table). The percentage of patients receiving systemic treatment did not change over the years. Median OS gradually increased from 11.3 months (95%CI 10.1-12.5) for patients diagnosed in 2013 to 33.3 months (95%CI 28.8-37.4) for patients diagnosed in 2019. Remarkably however, median OS was lower for patients diagnosed in 2020 and 2021 (24.8 months; 95%CI 21.1-28.2 and 18.8 months; 95%CI 17.6-NR). When excluding previously adjuvant-treated patients or looking at synchronous metastatic melanoma only, the same trends were seen. Similarly, differences in MSS mirrored our OS findings. Median OS and MSS can be found in the table. Conclusions: After a continuous survival improvement for advanced melanoma patients between 2013-2019, outcomes in 2020 and 2021 are remarkably poorer. The decreased performance status at the start of systemic treatment suggests that COVID-related delays might have played a role. [Table: see text]