The Proportion Cured of Patients with Resected Stage II-III Cutaneous Melanoma in Sweden

Simple summary Patients diagnosed with stage II-III cutaneous melanoma (CM) are at high risk of recurrences, but the CM-specific survival ranges from approximately 40-70%. Here, the cure proportions and survival among uncured stage II-III CM patients were estimated. The 1- and 5-year relative survival ratios, cure proportions and the median survival times of uncured stage II-III CM patients in Sweden (n = 6466) were calculated based on data from the nationwide population-based Swedish Melanoma Register 2005-2013 with a follow-up through 2018. Proportions cured by surgery are low for sub-groups of stage II-III cutaneous melanoma showing that cure analyses can serve as a complement to established survival analyses. Background: Cure proportion represents the proportion of patients who experience the same mortality rate as the general population and can be estimated together with the survival of the proportion experiencing excess mortality (the uncured). The aim was to estimate the cure proportions and survival among uncured stage II-III cutaneous melanoma (CM) patients. Methods: 1- and 5-year relative survival ratios, cure proportions and the median survival times of uncured stage II-III CM patients in Sweden (n = 6466) were calculated based on data from the nationwide population-based Swedish Melanoma Register 2005-2013 with a follow-up through 2018. Results: Stages IIB and IIC showed significant differences in standardized cure proportions vs. stage IIA CM (0.80 (95% CI 0.77-0.83) stage IIA; 0.62 (95% CI 0.59-0.66) stage IIB; 0.42 (95% CI 0.37-0.46) for stage IIC). Significant differences in standardized cure proportions were found for stages IIIB and IIIC-D CM vs. stage IIIA (0.76 (95% CI 0.68-0.84) stage IIIA; 0.52 (95% CI 0.45-0.59) stage IIIB; 0.35 (95% CI 0.30-0.39) for stage IIIC-D). Conclusions: The results are emphasizing the poor prognosis with low proportions cured by surgery only for sub-groups of stage II-III CM, specifically within stages IIB-C CM.Funding Agencies|Swedish Cancer SocietySwedish Cancer Society [190278Fk01H, JCIA 210406]; Cancer Research Foundations of Radiumhemmet [181083]; Swedish Medical Society [SLS-934511, SLS-961466]; Swedish Society for Medical Research (2017); KI Funds [FS-2020:0007]; Region Stockholm [2021-01]; Hudfonden [4-1880/2020]; Sigurd and Elsa Golje Memorial Fund, Folkfonden (2020) [LA-2020-0148]