Increased Risk of Squamous Cell Carcinoma of the Skin and Lymphoma Among 5,739 Patients with Bullous Pemphigoid: A Swedish Nationwide Cohort Study
Zeyad Albadri, Kristofer Thorslund, Henrike Häbel, Oliver Seifert, Carina Grönhagen
Evidence about the association of bullous pemphigoid and the risk of cancer is conflicting. Patients diagnosed with bullous pemphigoid (n = 5,739) between 2005 and 2016 were matched with a control cohort from the general population (n = 17,168) to estimate their overall and specific risk of cancer. The risk of squamous cell cancer of the skin (cSCC) was increased in patients with bullous pemphigoid (hazard ratio (HR) 1.3; 95% confidence interval (CI) 1.1–1.6). The risk of lymphoma within one year after bullous pemphigoid diagnosis was also increased (HR 3.1; 95% CI 1.3–7.6). While overall cancer risk prior to diagnosis of bullous pemphigoid was similar in cases and controls (prevalence odds ratio (POR) 1.0; 95% CI 0.9–1.0), the risk of male genital cancer within one year prior to diagnosis of bullous pemphigoid was lower in cases (POR 0.4; 95% CI 0.2–0.8). Clinicians must be aware of the increased risk of cSCC and lymphoma in patients with bullous pemphigoid.
Bullous pemphigoid is an autoimmune skin disorder that has a huge impact on patients’ lives. It has been associated with an increased risk of cancer. To evaluate the significance of this association, data from 5,739 patients in Sweden with bullous pemphigoid were reviewed and compared with data from a control group with no previous diagnoses of bullous pemphigoid. The results show that the risk of squamous cell cancer of the skin is increased in patients with bullous pemphigoid. Patients were also more often diagnosed with lymphoma within 1 year after diagnosis of bullous pemphigoid. However, no increased overall cancer risk was found in patients with bullous pemphigoid.