A population-based case-control study in Utah reported that heavier tattoo exposure was associated with lower odds of melanoma. Patients who had four or more tattoo sessions showed reduced risk for both invasive and overall melanoma compared with those who were never tattooed. Having three or more large tattoos was also associated with lower odds. By contrast, one tattoo session was linked with higher odds of melanoma, particularly among women. Patients who received their first tattoo before age 20 had lower odds of invasive melanoma compared with patients who were never tattooed.
The study included 1,167 patients with melanoma, of whom 566 had in situ disease and 601 had invasive disease, diagnosed between January 2020 and June 2021. Controls were 5,835 participants from the Utah Behavioral Risk Factor Surveillance System survey, frequency-matched by sex, age group, and race or ethnicity. Cases were identified through the Utah Cancer Registry and completed structured interviews, while controls answered added questions on tattoo history. Researchers adjusted models for age, sex, race or ethnicity, education, smoking, physical activity, and body mass index.
Limitations included the absence of several melanoma risk factors among controls such as indoor tanning, pigment phenotype, family history, and sunburn history. This lack of information may have introduced unmeasured confounding. The case response rate was 41%, raising the possibility that tattoo prevalence differed between participants and nonparticipants. In addition, information on tattoo sun exposure was not collected. Researchers noted that these factors may have influenced the observed associations.
Rachel D. McCarty, PhD, of the Huntsman Cancer Institute at the University of Utah and the International Agency for Research on Cancer, WHO, and colleagues, explained, “It is possible that tattooing may elicit beneficial immune responses that could contribute to immune surveillance of pre-cancerous cells, preventing progression to melanoma.”
Researchers emphasized that more studies with detailed data on melanoma risk factors are needed to clarify these findings.
Full disclosures can be found in the study.
