The Use and Utility of Adjuvant Checkpoint Inhibitors in Elderly Patients with Melanoma: A Single Institution...

Background: Elderly patients have low utilization of adjuvant ICIs, although they achieve similar RFS benefits as younger patients. It remains unclear why elderly patients use adjuvant ICIs less frequently and whether toxicity impacts treatment utilization. Methods: Adult patients with stage III melanoma treated from 2017 to 2023 at a single academic cancer center were retrospectively identified. Multivariable logistic regressions evaluated the association of age with receipt of adjuvant ICIs and toxicity. RFS was assessed using Kaplan-Meier and multivariable Cox proportional hazards regression. Results: Among 240 patients, those aged ≥ 75 years were less likely to receive adjuvant ICI than those aged 18-74 years (aOR: 0.30; 95% CI: 0.11-0.80). Among 53 (22.1%) patients who did not receive adjuvant ICI, 58% declined treatment, 15% were not offered adjuvant ICI by provider, 9% had a comorbid autoimmunity, and 6% had another comorbidity. A total of 12% of patients aged 75-80 years old declined treatment versus 33% of those aged 80-90 years old. Older age was not associated with toxicity, treatment interruption, or discontinuation from adjuvant ICI. Adjuvant ICI was associated with low recurrence (aHR: 0.76; 95% CI: 0.63-0.92), whereas age ≥ 75 years was associated with higher recurrence risk (aHR: 1.79; 95% CI: 1.04-3.10) and low overall survival (aHR: 3.07; 95% CI: 1.43-6.57) compared to patients aged 18-74 years. Conclusions: Older patients with stage III melanoma were less likely to receive adjuvant ICIs, despite similar toxicity, treatment interruption, and discontinuation rates across age groups. Because adjuvant therapy is associated with lower recurrence risk, efforts to better understand and address age-related differences in treatment use are warranted.