Tattoos and risk of cutaneous melanoma and non-melanoma skin cancer in France

Background: With the increasing popularity of decorative tattooing, which entails the intradermal injection of inks that may contain carcinogens, investigating the related potential skin cancer risk is a public health priority. Methods: We used data from the Cancer Risk Attributable with the Body Art of Tattooing (CRABAT) study, nested in the French national cohort Constances (adults aged 18-69 years recruited in 2012-2018). Tattoo exposure was collected in 2020-23. Skin cancers overall, cutaneous melanoma (CM), and non-melanoma skin cancer (NMSC) diagnosed during 2007-21 were retrieved from national health insurance data. As exposure information was collected after possible disease ascertainment, risks of skin cancer with prior tattoo exposure were assessed using (i) Logistic regression and (ii) retrospective cohort analyses using Cox proportional hazards model. Results: Among 111 074 participants, 1789 skin cancers (1.6%) were recorded (693 CM, 1096 NMSC). No association was found between binary tattoo exposure and any skin cancer type. In logistic regression, tattoo body surface >2 hand palms was associated with lower overall skin cancer risk (OR = 0.21, 95% CI: 0.05-0.83; reference no tattoos). This association was not significant in the Cox model, but the suggestive dose-response relationship remained, with HRs of 1.14, 0.60, and 0.26 for tattoo body surface of 0-1, 1-2, and >2 hand palms, respectively. Conclusion: Large tattoo surfaces were tentatively associated with reduced overall skin cancer risk. While these finding merits further research, small case numbers and the retrospectively collected data might have biased the results.