The impact of prognostic factors and comorbidities on survival in older adults with stage I- III cutaneous melanoma in Southwest Finland: A register study

Introduction: Despite being diagnosed with thicker and more often ulcerated melanomas, cancer-specific survival (CSS) is not necessarily inferior in older adults with melanoma compared to younger patients. Materials and Methods: Our aim was to evaluate the impact of baseline melanoma-specific prognostic factors and comorbidities on recurrence-free survival (RFS), CSS, and overall survival (OS) in patients aged 70-79 (n = 474) and >= 80 years (n = 286) with resected stage I - III cutaneous melanoma in Southwest Finland between January 1, 2000 and December 31, 2020. Patients were restaged according to the 8th edition of TNM classification, and comorbidities were assessed using the Charlson Comorbidity Index (CCI). Results: Patients aged >= 80 years had thicker and more commonly ulcerated melanomas: 43.0%, 40.9%, and 16.1% of patients aged >= 80 and 56.5%, 25.3%, and 18.1% of patients aged 70-79 years were diagnosed with stage I, II, and III melanoma, respectively. Multiple comorbidities (CCI >= 2) were more common and sentinel lymph node biopsy less frequently performed in patients aged >= 80 years. RFS and CSS were similar in patients aged 70-79 years and >= 80 years: median RFS 13.8 years vs not reached, with the hazard ratio of melanoma recurrence or death from melanoma 1.25 (95% confidence interval [CI]: 0.91-1.71); median CSS was not reached, with the hazard ratio of death from melanoma 1.12 (95%CI: 0.81-1.75). The proportion of patients who were alive with melanoma recurrence or had died from melanoma was similar in both age groups. In multivariable analysis, higher pathological stage was the only independent risk factor for short RFS regardless of age group, sex, CCI, and tumor ulceration. Higher stage and male sex were associated with short CSS. Age >= 80 years, stage III disease, and CCI >= 2 were associated with short OS and female sex with long OS in multivariable analysis. Discussion: Pathological stage was the most influential factor determining RFS and CSS in older adults with resected stage I - III melanoma. Concerning OS, age >= 80 years, stage III disease, and multiple comorbidities had a significant negative impact.