Relative risk for cancer in mucous membrane pemphigoid associated with antibodies to the β4 integrin subunit

Background Mucous membrane pemphigoid (MMP) is a mucocutaneous vesiculobullous autoimmune disease characterized by autoantibodies to components of the basement membrane zone (BMZ). Recently, it has been reported that patients with MMP who have autoantibodies to laminin 5, known as anti-epiligrin cicatricial pemphigoid (AECP) have a high incidence of malignancy. Objective The purpose of this study was to determine the association between malignancy and MMP in patients with antibodies to beta 4 integrin. Methods The incidence of cancer was studied in 79 patients with MMP and/or ocular cicatricial pemphigoid (OCP) who had antibodies to human beta 4 integrin subunit. In each patient, the diagnosis was made by histology and confirmed by immunopathology of affected tissues. It was compared to the expected incidence, for age- and gender-matched individuals, in the National Cancer Institute's Surveillance, Epidemiology and End Results (NCISEER) database. Results Of 79 patients, 3 had cancer. The relative risk (RR) for cancer in patients with MMP and/or OCP, with autoantibodies to human beta 4 integrin subunit was 0.29 (95% CI 0.62-8.77). The expected number in the NCISEER database was 10.37. This difference was statistically significant (P < 0.01). Conclusions This incidence of cancer in MMP/OCP patients, with antibodies to human beta 4 integrin subunit is considerably lower than expected. Preliminary observations in this and other studies suggest that serological subsets of MMP, based on antigen reactivity, have a different clinical course, prognosis and associations with cancer.