Exploring lifestyle confounding in the association between tattoos and cancer: A latent class analysis of tattooing and cervical cancer risk within the CRABAT study

Background: Recent studies report increased hematologic cancer risk with tattooing, an exposure highly correlated with sociodemographic and lifestyle patterns. To assess potential confounding by such factors in associations between tattooing and cancer, we studied cervical cancer, a cancer unlikely to be causally related to tattooing. We applied latent class analysis (LCA) to group women into latent lifestyle profiles based on sociodemographic, lifestyle, and health-related variables, and assessed how such profiles may confound associations between tattooing and cervical cancer Methods: We analyzed data from 50,769 women in the Cancer Risk Associated with the Body Art of Tattooing (CRABAT) study nested within the French national Constances cohort. Logistic regression models estimated associations between tattoos and cervical cancer, adjusting for confounders and latent lifestyle profile. Additional models were stratified by latent lifestyle profile. Results: We selected a five-profile LCA model to balance model fit and interpretability. In minimally adjusted models, women with tattoos had a higher cervical cancer risk (OR=1.54 [95% CI 1.15–2.05]). Associations were attenuated after adjusting for known confounders (1.33 [0.99–1.77]), and a bit further after adjusting for latent profile (1.29 [0.95–1.73]). Stratified models showed strong variations, with ORs ranging from 0.99 [0.37–2.61] in the younger profile to 2.56 [1.23–5.34] in the socially-advantaged profile. Conclusions: While elevated risk among tattooed individuals persisted after adjustment for known confounders, LCA was able to differentiate risk patterns between latent lifestyle profiles. LCA may be useful when complex confounding is likely, such as in studies of tattoos and cancer risk.