Trends in Survival and Cure Indicators of Thin and Thick Cutaneous Malignant Melanoma in Italy.

BACKGROUND: In Italy, cure indicators of cutaneous malignant melanoma according to Breslow tumour thickness have never been assessed. OBJECTIVES: To evaluate the time trend in 1-year net survival (NS), 5|1-year conditional NS (CNS) and cure fraction (CF). METHODS: Data from 10 cancer registries and 13,377 patients aged 15-74 years were used. Five|1-year CNS was defined as the probability of surviving 5 years given that the patient has survived 1 year. CF was defined as the proportion of patients with the same life expectancy as the general population. One-year NS and 5|1-year CNS were contrasted between 2013-2017 and 2003-2007, and CF between 2015 and 2005. RESULTS: For lesions up to 4 mm thick, 1-year NS reached a level > 98.0%. In 2013-2017, 5|1-year CNS was above 90% for men and women with lesions up to 2.0 mm thick and increased markedly for men with lesions > 2.0-4.0 mm thick (65.1% to 82.4%) and > 4.0 mm thick (57.6% to 69.4%). The CF of patients with a melanoma ≤ 1.0 mm thick was approximately 100% in both sexes, and nearly doubled from 2005 to 2015 (28% to 54%) for men aged 55-74 years with a melanoma > 4.0 mm thick. CONCLUSIONS: Patients with a melanoma ≤ 1 mm thick have the same life expectancy as the general population. The increase in the CF of men with thick lesions supports the hypothesis that novel therapies, approved in Italy since 2013, offer the possibility of cure.