Association between cancer and immunosuppressive therapy--analysis of selected studies in pemphigus and pemphigoid

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.

Literature was accessed through PubMed (all years available), using the search terms cancer, immunosuppressive agents, pemphigoid, and pemphigus.

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.

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, cyclosporine, 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.

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.