Inherited functional variants of the lymphocyte receptor CD5 influence melanoma survival

Despite the recent progress in treatment options, malignant melanoma remains a deadly disease. Besides therapy, inherited factors might modulate clinical outcome, explaining in part widely varying survival rates. T‐cell effector function regulators on antitumor immune responses could also influence survival. CD5, a T‐cell receptor inhibitory molecule, contributes to the modulation of antimelanoma immune responses as deduced from genetically modified mouse models. The CD5 SNPs rs2241002 (NM_014207.3:c.671C > T, p.Pro224Leu) and rs2229177 (NM_014207.3:c.1412C > T, p.Ala471Val) constitute an ancestral haplotype (Pro224‐Ala471) that confers T‐cell hyper‐responsiveness and worsens clinical autoimmune outcome. The assessment of these SNPs on survival impact from two melanoma patient cohorts (Barcelona, N = 493 and Essen, N = 215) reveals that p.Ala471 correlates with a better outcome (OR= 0.57, 95% CI = 0.33–0.99, Adj. p = 0.043, in Barcelona OR = 0.63, 95% CI = 0.40–1.01, Adj. p = 0.051, in Essen). While, p.Leu224 was associated with increased melanoma‐associated mortality in both cohorts (OR = 1.87, 95% CI = 1.07–3.24, Adj. p = 0.030 in Barcelona and OR = 1.84, 95% CI = 1.04–3.26, Adj. p = 0.037, in Essen). Furthermore survival analyses showed that the Pro224‐Ala471 haplotype in homozygosis improved melanoma survival in the entire set of patients (HR = 0.27, 95% CI 0.11–0.67, Adj. p = 0.005). These findings highlight the relevance of genetic variability in immune‐related genes for clinical outcome in melanoma.