A single-center retrospective analysis of prognoses in patients with melanoma brain metastases and effectiveness of treatment in Japan.

Abstract

Melanoma brain metastasis (MBM) has a poor prognosis, although recent treatments, including immune checkpoint inhibitors and targeted therapy, have improved the prognosis. However, these systemic therapies have been reported to be less efficient for Asian patients. We investigated the survival of Asian patients with MBM and the effectiveness of systemic therapies. We retrospectively reviewed the survival rates of patients diagnosed with MBM between January 2011 and December 2021 at the National Cancer Center Hospital in Tokyo, Japan. In addition, we identified factors associated with survival using Cox regression analysis. A total of 135 patients were included. The median overall survival (OS) after an MBM diagnosis was 7.8 months (95% confidence interval [CI] 6.1-9.6). The 6-month and 1-year survival rates were 60.7% and 34.8%, respectively. We identified the prognostic factors of MBM, including non-acral primary location, low serum LDH levels, systemic therapy of single-agent immune checkpoint inhibitors (ICIs) or targeted therapies (TTs), and radiotherapy of stereotactic irradiation (STI). We found no significant difference in effectiveness between single-agent ICIs, the combination of Nivolumab and Ipilimumab (COMBI-ICI), and TTs (COMBI-ICI vs. single-agent ICI, hazard ratio 0.71, 95% confidence interval 0.27-1.88, p = 0.49; COMBI-ICI vs. TT: hazard ratio 0.46, 95% confidence interval 0.14-1.55, p = 0.21). Systemic therapy and radiotherapy have improved the survival of MBM patients, but the survival of Asian patients remains poor. Our findings suggest that COMBI-ICIs are not significantly more effective than single-agent ICI or TT in treating MBM.