Tattooing and risk of melanoma: a population-based case-control study in Utah

Tattooing can deliver carcinogens directly into the skin and cause immunological responses, and yet the relationship between tattooing and melanoma risk is unknown.

In a population-based case-control study with 1167 melanoma cases (566 in situ; 601 invasive) and 5835 frequency-matched controls, we examined tattooing and melanoma risk using multivariable logistic regression to calculate odds ratios (ORs) and 95% confidence intervals (CIs).

Although ever receiving a tattoo was not strongly associated with melanoma risk, heavier tattooing exposure was associated with decreased risk. Overall melanoma risk was decreased among individuals who had received 4 or more tattoo sessions (OR = 0.44, 95% CI = 0.27 to 0.67) and individuals who had 3 or more large tattoos (OR = 0.26, 95% CI = 0.10 to 0.54) compared with those who were never tattooed. Invasive melanoma risk was also decreased among individuals who received their first tattoo before age 20 (OR = 0.48, 95% CI = 0.29 to 0.82) compared with never tattooed individuals.

Our findings suggest that more tattoo exposure is associated with reduced melanoma risk, which does not support previously hypothesized associations between tattooing and increased melanoma risk. Unmeasured confounding is likely to contribute to our findings because we were not able to control for important melanoma risk factors. Potential causes of these associations could include sun exposure-related behaviors or immune responses to tattooing. Further investigation is warranted to clarify these relationships.