Mucous membrane pemphigoid and malignancy: Systematic review and meta-analysis of 1429 patients

Mucous membrane pemphigoid (MMP) is a rare autoimmune blistering disorder associated with higher rates of malignancy. To identify factors associated with malignancy in MMP. We conducted a systematic review and meta-analysis on all studies reporting MMP patients with known malignancy status. Forty-seven studies were included, representing 1429 MMP patients. Of these, 221 (15.5%) had a history of malignancy. Of the 104 (7.3%) patients with extractable cancer type, the most frequent were as follows: breast cancer (15.4%), skin cancer (11.5%), and lung cancer (11.5%). The pooled analysis detected 3 variables that varied significantly between MMP patients with cancer or without the following: ocular involvement, dermal pattern on indirect immunofluorescence (IIF) using salt-split skin substrate, and circulating antilaminin 332 antibodies. According to proportional meta-analyses, the malignancy rate in patients with antilaminin 332 antibodies was 21% (95% CI, 0.13-0.28) and in patients with ocular involvement was 18% (95% CI, 0.12-0.24). Running meta-analysis was not possible for IIF due to the limited articles. Variations in study designs, sample sizes, and outcome measures limit the generalizability of data. This rigorous study identified 3 clinical features predictive of an associated malignancy: antilaminin 332 antibodies, dermal pattern on IIF, and ocular involvement.