Telomere length and skin cancer risk: A systematic review and meta-analysis of melanoma, basal cell carcinoma and squamous cell carcinoma.

Skin cancer is one of the most prevalent types of cancer worldwide, with its global incidence rising despite prevention efforts. Telomere length (TL) has emerged as a potential biomarker for cancer risk; however, its relationship with skin cancer risk remains incompletely understood. To explore the association between TL and the risk of melanoma, basal cell carcinoma (BCC) and squamous cell carcinoma (SCC), a systematic review and meta-analysis was conducted. Longer TL was significantly associated with an increased risk in melanoma (pooled odds ratio: 0.51; 95% confidence interval: 0.38-0.69; P<0.0001). A significant association between longer TL and increased melanoma risk was identified in both familial melanoma and the general population. Subgroup analyses revealed consistent associations across sex, population source and adjustments for confounding factors. Geographic stratification indicated stronger associations in studies conducted in the USA compared with those from European populations. A meta-analysis of BCC and SCC studies did not achieve statistical significance, although qualitative synthesis suggested a potential association between shortened TL and increased risk. The significant association of longer TL and increased melanoma risk diverges from the conventional hypothesis that telomere shortening elevates cancer risk, highlighting a cancer-type specific telomeric relationship. The inconclusive findings for BCC and SCC underscore the necessity for further detailed investigation. Large-scale prospective studies with standardized methodologies are imperative to validate these findings and explore the underlying mechanisms. The present findings suggested that TL could potentially serve as a valuable biomarker for melanoma risk stratification in dermatologic oncology.