Abstract: 【Abstract】 Objective To analyze the differences in clinicopathological features between non-elderly and elderly patients with melanoma, and to identify risk factors for prognosis in elderly patients with melanoma. Methods A retrospective analysis was conducted on clinical and pathological data collected from non-elderly （aged < 60 years） and elderly （aged ≥ 60 years） patients with melanoma, who were confirmedly diagnosed according to clinical manifestations and histopathological findings at the People's Hospital of Xinjiang Uygur Autonomous Region from January 2008 to December 2023. The differences in clinical and pathological characteristics between the two groups were analyzed using the chi-square test and Wilcoxon rank-sum test. Survival curves were estimated using the Kaplan-Meier method and log-rank test. The relationship between clinicopathological variables and overall survival was analyzed using a Cox regression model. Results A total of 233 patients with cutaneous melanoma were included, with the age being 60.3 ± 14.7 years, and the number of patients was highest in the age group of 60 - 69 years. There were 102 cases （43.8%） in the < 60 years old group and 131 cases （56.2%） in the ≥ 60 years old group. Compared with the < 60 years old group, the ≥ 60 years old group showed a significant increase in the proportion of patients with active tumor-infiltrating lymphocytes （P = 0.040）, proportion of those with Ki-67 index ≥ 30% （P = 0.010）, and Charlson comorbidity index （P = 0.002）, but a significant decrease in the proportion of patients with BRAF/KIT/NRAS mutations （P = 0.003）, proportion of those receiving surgical treatment （P = 0.034）, and proportion of those receiving adjuvant therapy （P = 0.042）. There was a significant difference in the overall survival between the two groups （log-rank test, χ2 = 6.10, P = 0.014）. The gender, metastasis status, presence or absence of ulceration, distant metastasis status, American Joint Committee on Cancer staging, Charlson comorbidity index, and Breslow thickness were important prognostic indicators affecting the overall survival in the elderly patients with melanoma. Multivariate Cox regression analysis showed that males （P = 0.015, HR = 4.622, 95% CI: 1.352 - 15.798）, presence of distant metastasis （P = 0.013, HR = 9.844, 95% CI: 4.621 - 59.763）, and Charlson comorbidity index ≥ 3 （P = 0.038, HR = 3.149, 95% CI: 1.067 - 9.294） were independent risk factors affecting the overall survival in the elderly patients with melanoma. Conclusions Compared with the non-elderly patients with melanoma, a higher Ki-67 index, a higher Charlson comorbidity index, less surgical treatment, and less adjuvant therapy were more common in the elderly patients with melanoma. Males, the presence of distant metastasis, and Charlson comorbidity index ≥ 3 appeared to be independent risk factors affecting the overall survival in the elderly patients with melanoma.

Key words: Melanoma, Aged, Clinicopathological characteristics, Overall survival, Prognostic factors