Association Between Cancer and Immunosuppressive Therapy—Analysis of Selected Studies in Pemphigus and Pemphigoid

Objective: To determine whether there is an association between the use of immunosuppressive agents (ISAs) and cancer in patients with pemphigus and pemphigoid—rare, potentially fatal diseases of the skin and mucous membranes, often requiring long-term use of ISAs. Data Source: Literature was accessed through PubMed (all years available), using the search terms cancer, immunosuppressive agents, pemphigoid, and pemphigus. Study Selection and Data Extraction: A retrospective review of the literature was conducted. Inclusion criteria for studies were: (1) English language, (2) diagnosis of pemphigus and/or pemphigoid based on histology and immunopathology, (3) more than 10 patients evaluated, (4) investigators had a high index of suspicion of cancer and patients were monitored for it, (5) follow-up information was provided for at least 1 year after initiation of therapy, and (6) absence of diagnosis of cancer before initiation of an ISA. Case reports were not included in the analysis. Data Synthesis: A total of 929 patients diagnosed with either pemphigus or pemphigoid in 17 studies were identified. Patients were divided into 2 groups. Group A comprised patients treated with azathioprine, cyclophosphamide, cyclosporins, or mycophenolate mofetil in combination with prednisone. In Group A. 22 cases of cancer were reported in 21 of the 218 patients (9.6%). Group B comprised patients treated with systemic corticosteroids only. In this group, cancer was reported in 11 of the 711 patients (1.5%). In this study there was no control group (untreated patients) and the sample sizes were small. Conclusions: Preliminary data suggest a possible association between the use of azathioprine, cyclophosphamide, and cyclosporine and increased susceptibility to cancer in patients with pemphigus and pemphigoid.