Telomere length and the risk of cutaneous melanoma and non-melanoma skin cancer: a review of the literature and meta-analysis

•Melanoma risk is associated with peripheral leucocytes telomere length.•Telomere lengthening is a likely mechanism of tumorigenesis for melanoma.•The choice of correct controls is key in studies on telomere and cancer risk.

There is much evidence supporting the role of telomeres in cancer pathogenesis, however the studies that investigated the association between telomere length and skin cancer risk provided inconsistent results. To help clarify this issue, we performed a systematic review and meta-analysis of published papers on the association between peripheral leukocytes telomere length (PLTL) and the risk of cutaneous melanoma and non-melanoma skin cancer (NMSC).We calculated summary relative risks (SRR) and 95% confidence intervals (95%CI) using random effect models with maximum likelihood estimates, and explored causes of between-studies heterogeneity of risk estimates.We included 1629 cutaneous melanoma and 1439 NMSC from eight independent studies published until March 2015. The SRR of cutaneous melanoma for those in the lowest (vs. highest) category of PLTL distribution was 0.25 (95% CI 0.09–0.67). The results were less clear for NMSC, with two studies reporting no association and one study showing an increase in risk for those in the lowest (vs. highest) category of PLTL distribution. For both cutaneous melanoma and NMSC, the between-studies heterogeneity was large, mainly due to inclusion of hospital-based case-control studies.Our meta-analysis shows evidence of an association between short PLTL and reduced risk for cutaneous melanoma.