Autoimmunity and hypothyroidism in patients with uveal melanoma

Among patients with advanced melanoma, the development of autoimmune phenomena or of hypothyroidism during therapy has been associated with a favourable outcome. The objective of this study was to determine the prevalence of autoimmunity and of hypothyroidism in the melanoma population as a whole and to determine if these disease states confer a survival advantage for patients with metastatic disease. We report our findings in the uveal melanoma population. The study population (n = 91) consisted of all patients registered at this institution with the diagnosis of uveal melanoma during a 2 year study period. Eight (8.8%) had a systemic autoimmune disease; 12 (13.2%) were hypothyroid, including 9/46 (19.6%) females. Survival of the stage 4 patients was determined from diagnosis of the primary tumour (SvDx) and from diagnosis of metastatic disease (SvMt), and was compared to that of age/sex matched stage 4 controls. For autoimmune patients versus controls, the median SvDx was 111 months vs 37 months (P = 0.2734) and the median SvMt was 17 months vs 4 months (P = 0.0887). For the hypothyroid patients versus controls, the median SvDx was 58 months vs 49 months (P = 0.5348) and the median SvMt was 4 months vs 8 months (P = 0.2437). We conclude that there is a trend toward longer survival from the date of metastasis in uveal melanoma patients with a systemic autoimmune disorder, suggesting that systemic autoimmunity may play a role in modifying the activity of established metastases. This trend is not seen among the uveal melanoma patients with hypothyroidism. The high prevalence of hypothyroidism suggests a possible molecular interaction between the two disease processes.