Risk of Vulvar HSIL and Penile Neoplasias in Anogenital Lichen Planus: A Case-Control Study

Objective Lichen planus (LP) is a chronic inflammatory skin disease that may affect the skin, scalp, nails, and mucosa. The aim of this study was to investigate the risk of genital premalignant and malignant conditions in patients with anogenital LP (agLP). Methods We identified 60 male and 56 female patients with agLP by searching the biobank archives for a genital or perianal skin biopsy showing LP between 2004 and 2020. We also included 10 randomly selected age- and sex-matched controls for each patient. The risks of genital cancers and their precursors were evaluated. Results The incidence of agLP was 1.54 per 100,000 men and 1.36 per 100,000 women. There was no statistical difference between male and female incidence (p =.5721). The odds ratio (OR) for high-grade squamous intraepithelial lesion (HSIL) of the vulva was 31.2 (95% CI = 2.46–1645.00; p =.01). The OR for penile neoplasias could not be calculated because control patients had no neoplasias, but the difference was suggestive of statistical significance (95% CI = 1.90–infinite; p =.008). The mean age at the time of diagnosis of agLP was 59.9 years (median 62 years) in female patients and 40.8 years (median 33 years) in male patients. The difference in the mean ages of female and male patients was statistically significant (95% CI = 11.92–26.13; p <.001). Conclusions Patients with agLP may have an increased risk for vulvar HSIL and penile neoplasia.