Melanoma in older patients in Switzerland: A comparison across age groups including patients over the age of 80 years

BACKGROUND: With the ageing population and the increasing incidence of melanoma in recent years, melanoma management in the oldest is becoming increasingly important. We aimed to assess Breslow thickness (BT), relative survival (RS) and trends in immunotherapy use in younger, older, and the oldest Swiss patients. MATERIAL AND METHODS: Patients diagnosed with invasive cutaneous melanoma and reported to Swiss cantonal cancer registries between 2012 and 2021 were included. Age was divided in three categories: < 70, 70-79 and ≥ 80 years. Differences in median BT at diagnosis and changes over time were assessed. Percentages of stage 3 and 4 patients receiving immunotherapy by age and year were calculated. Relative survival was calculated and multivariable analyses estimating the Relative Excess Risk of death (RER) were conducted. RESULTS: Overall, 27 649 patients were included. Age-standardized incidence rates increased across all age categories, with the steepest rise observed in older patients (EAPC: 2.9% (95% CI: 1.0-4.8) for 70-79 years and 2.6% (1.6-3.6) for ≥ 80 years vs. 1.2% (0.2-2.3) for < 70 years). Median BT increased with age, with patients aged ≥ 80 years having the highest median BT at diagnosis (0.80 (IQR: 0.40-2.50)). The percentage of stage 3 and 4 patients aged ≥ 80 years receiving immunotherapy increased from 3.45% in 2012 to 42.47% in 2021 (p < 0.001) but remained lower than in younger patients. Survival decreased with increasing age: Patients younger than 70 years had a 5-year survival of 96.2% (95% CI: 95.8-96.6), compared to 93.7% (95% CI: 92.6-94.9) among those aged 70-79 years, and 88.7% (95% CI: 86.0-91.4) among patients aged 80 years and older. Relative survival of patients aged ≥ 80 years was worse compared to younger patients (<70 years), even after adjusting for sex, BT, stage, and location (RER: 2.378; std. error: 0.108; p < 0.001). CONCLUSION: Swiss melanoma patients aged ≥ 80 years are diagnosed with thicker melanomas, receive more conservative treatment, and experience worse survival. These findings highlight the need to include the oldest patients in future melanoma research, strengthen secondary prevention efforts, and ensure they benefit from optimal therapeutic advances.