Abstract
BACKGROUND: Melanoma survivors have a high risk of developing second primary neoplasms, both cutaneous melanoma (SPCM) and non-cutaneous melanoma (SPNCM), but little is known about the survival impact of the diagnosis of SPCM and SPNCM. OBJECTIVES: To compare overall survival between melanoma survivors with first primary melanoma and SPCM/SPNCM by stage at diagnosis of second primary neoplasms. METHODS: Among cutaneous (CM) and non-cutaneous melanoma (NCM) survivors of all ages, SPCM (N = 7314) or SPNCM (N = 157) between 2004 and 2020 were identified from the Surveillance, Epidemiology, and End Results 17 Research Plus database. Flexible parametric modelling was conducted to evaluate the time-varying effect of SPCM and SPNCM, compared to single melanoma, on survival. RESULTS: Over the study period, 3.4% of patients had a SPCM (12.9% regional/distant-stage) and 0.1% had a SPNCM (36.3% regional/distant or unknown-stage). Compared with single CM, patients with SPCM (regional/distant-stage hazard ratio [HR] = 1.71, 95% confidence interval [CI] = 1.55-1.89; localized-stage HR = 1.09, CI = 1.01-1.18) and regional/distant-stage SPNCM (Year 1: HR = 1.56, CI = 0.81-3.03) had worse overall survival. Among NCM survivors, regional/distant-stage SPCM (HR = 2.67, CI = 1.73-4.13) had a more pronounced impact on decreased overall survival than localized-stage SPCM (HR = 1.19, CI = 0.71-1.99) when compared with single NCM, with similar trends seen for regional/distant-stage SPNCM (Year 2: HR = 1.39, CI = 0.76-2.54) relative to localized-stage SPNCM (Year 2: HR = 0.96, CI = 0.61-1.50). CONCLUSIONS: The reduction in survival among melanoma survivors with SPCM and SPNCM suggests the potential need for prevention and early detection of SPCM and SPNCM.