Assessment of Overall and Specific Cancer Risks in Patients With Hidradenitis Suppurativa

This population-based study examines the prevalence of cancer in patients with hidradenitis suppurativa. Importance Large population-based studies investigating the risks of overall and specific cancers among patients with hidradenitis suppurativa (HS) are limited. Objective To assess the overall and specific cancer risks in patients with HS compared with the risks in patients without HS in the Republic of Korea. Design, Setting, and Participants A nationwide population-based cohort study, using the Korean Health Insurance Review and Assessment Service database was conducted over a 2-year period from January 1, 2007, to December 31, 2008. Individuals in the control group who were never diagnosed with HS or cancer during the washout period were randomly extracted and matched by age, sex, index year, and insurance type at a case-control ratio of 1:8, and patients with newly diagnosed HS between January 1, 2009, and December 31, 2017, were included. Follow-up data on incident cancer from January 1, 2009, to December 31, 2018, were included. Main Outcomes and Measures The overall and specific cancer incidence rates were calculated per 100.000 person-years in patients with HS and in the matched control cohort. The risk for cancers was assessed by multivariable Cox regression models in patients with HS compared with the matched control cohort. Results In total, 22.468 patients with HS and 179.34 matched controls were included in the study. The mean (SD) age was 33.63 (17.61) years and 63.7% of the participants in both groups were male. The adjusted hazard ratio (aHR) of overall cancer in patients with HS was 1.28 (95% CI, 1.15-1.42). Patients with HS had significantly higher risk for Hodgkin lymphoma (aHR, 5.08; 95% CI, 1.21-21.36), oral cavity and pharyngeal cancer (aHR, 3.10; 95% CI, 1.60-6.02), central nervous system cancer (aHR, 2.40; 95% CI, 1.22-4.70), nonmelanoma skin cancer (HR, 2.06; 95% CI, 1.12-3.79), prostate cancer (aHR, 2.05; 95% CI, 1.30-3.24), and colorectal cancer (aHR, 1.45; 95% CI, 1.09-1.93). Conclusions and Relevance In this study, HS appeared to be associated with a significantly increased risk of overall cancer as well as several specific cancers. Question Is hidradenitis suppurativa associated with increased risks of overall and specific cancers in patients with this condition? Findings In a population-based study, 22.468 patients with hidradenitis suppurativa in the Republic of Korea had increased risks of overall cancer compared with 179.734 individuals without hidradenitis suppurativa. In addition, the risks of specific cancers, such as Hodgkin lymphoma and oral cavity and pharyngeal, central nervous system, nonmelanoma skin, prostate, and colorectal cancer, were increased. Meaning More intense cancer surveillance may be warranted in patients with hidradenitis suppurativa.