Comorbidity in patients with Lichen sclerosus: a retrospective cohort study

Lichen sclerosus (LS) is a chronic lymphocyte mediated inflammatory mucocutaneous disease of unknown aetiology with a predilection for the anogenital region, and affecting both sexes. The disease is characterized by pain, intolerable itching and scarring. In late stages of LS, disfiguring scarring can drastically alter the structural anatomical architecture of the genitals. The association between genital LS and different malignant tumours is a concern that needs to be further investigated. An association between LS and several autoimmune diseases has been confirmed in recent studies. All registered citizens of Region Jönköping, Sweden were included in the present study. Patients diagnosed with LS (n = 5680) between 2001 and 2021 were identified using ICD-10 code L90.0 and selected as cases. All other individuals (n = 362 568) served as controls. Odds ratios (ORs) for the selected comorbidity were calculated and adjusted for age and sex. The cumulative incidence of LS for the entire population over a 20-year period was 1.54% (15.4 per 1000 people). The cumulative incidences over a 20-year period for females and males were 2.13% and 0.97%, respectively. This study confirmed the association between LS and vulvar cancer (OR = 17.4; 95% CI 12.1-25.3), penis cancer (OR = 9.1; 95% CI 4.3-18.9), prostate cancer (OR = 2.0; 95% CI 1.6-2.4) and breast cancer (OR = 1.6; 95% CI 1.4-1.8). LS was also associated with Crohn´s disease (OR = 2.0; 95% CI 1.6-2.6) and diabetes mellitus type 1 (OR = 1.9; 95% CI 1.6-2.1). The present study revealed novel important data regarding the association of LS with cancer and autoimmune diseases, emphasising the importance of sufficient treatment and follow-up of patients with LS. However, future studies are needed to confirm these results and the potential role of LS in the development of cancer.