Congenital ichthyosis is associated with cutaneous malignancies in a case-control study

Background

Congenital ichthyoses are a heterogeneous group of keratinization disorders. Though there are case reports describing skin cancer development in congenital ichthyosis patients, the risk of skin cancer in congenital ichthyosis patients compared to the general population is unknown.

Objective

We aimed to evaluate the association of congenital ichthyosis with cutaneous malignancies using a large national database.

Methods

A nested case-control study using the National Institutes of Health All of Us database was conducted analyzing participants ≥ 18 years with CI and controls matched 1:12 by age, sex, and race/ethnicity. Multivariate logistic regression assessed odds ratios for CI and skin cancer associations (P < 0.05).

Key results

A total of 198 CI participants and 2,376 controls were included in the final analysis. Mean age of CI participants was 67.2 years, with 56.1% female and 67.7% white, similar to controls (P = 0.97, P = 1, P = 0.99, respectively). After controlling for smoking, alcohol, obesity, and mobility, congenital ichthyosis was associated with actinic keratosis (AK) (OR = 3.65; 95% CI 1.00-5.51; P < 0.001), melanoma (OR = 2.39; 95% CI 1.05–5.45; P = 0.04), and basal cell carcinoma (BCC) (OR = 1.90; 95% CI 1.03–3.39; P = 0.03), but not squamous cell carcinoma (SCC) (P = 0.50).

Conclusion

We found that CI was associated with cutaneous malignancies. Larger scale studies are needed to confirm these findings with narrower confidence intervals. We recommend routine skin cancer surveillance in CI patients pending additional studies clarifying risk of cutaneous malignancy.