Immunotherapy Outcomes in Advanced Melanoma in Relation to Age

Older age is a melanoma risk factor. Elderly individuals are likelier to have immunosenescence, which could help melanoma cells escape immune surveillance. Hence, it is believed that elderly people cannot mount a potent immune response to checkpoint inhibitors to eliminate melanoma.

To investigate age-related differences in the time to progression, overall survival, and immunotherapy-related adverse events among patients with metastatic melanoma who received checkpoint inhibitors.

We retrospectively identified patients at our institution between January 2012 and December 2016 with stage IV melanoma who received at least 1 dose of ipilimumab, pembrolizumab, nivolumab, or combined ipilimumab and nivolumab. Demographic, pathologic, and clinical characteristics were obtained. Immune-related response criteria were used to define responses.

Twenty-nine patients were younger than age 65 years and 31 were age 65 years or older. Time to progression was comparable between the age groups (hazard ratio = 0.79, 95% confidence interval = 0.37-1.70, p = 0.46). Overall survival was not significantly different after immunotherapy between groups (hazard ratio = 0.75, 95% confidence interval = 0.31-1.82, p = 0.491). Overall, immunotherapy-related adverse events were comparable between groups, with 62% in younger patients (18/29) and 45% in older patients (14/31 p = 0.19). Of 60 patients, 30 responded to immunotherapy. Nonresponders were more likely than responders to have BRAF-mutated melanomas (16 [53.3%] vs 8 [27.6%]; p = 0.04) and less likely to have immunotherapy-related adverse events (12 [40%] vs 20 [66.7%]; p = 0.04).

Aging does not seem to affect response to checkpoint inhibitors. Elderly patients with metastatic melanoma should be treated similarly to younger patients.