Association of bullous pemphigoid with malignancy: A systematic review and meta-analysis

Background Studies evaluating whether malignancy rate is increased in patients with bullous pemphigoid (BP) have reached conflicting results. Objective We sought to determine whether BP is associated with malignancy. Method Medline, EMBASE, the Cochrane library, and reference lists of included studies were searched for comparative studies that evaluated the relationship between BP and malignancy. Data were analyzed on the basis of study design: cross-sectional, case control, and cohort. A meta-analysis was performed by using a random effects model to estimate pooled odds ratio. Results The review included 8 studies. No association between BP and overall cancer was found for any of the study designs. Although a single cohort study reported an association with lymphoid leukemia and kidney and larynx cancer, a pooled analysis of case-control studies did not. A pooled analysis of cross-sectional studies found a significant association between BP and hematologic malignancies. Limitations The paucity of well-designed studies hindered the possibility of proving or disproving the BP-cancer association. Conclusion We did not find an association of BP with overall malignancy, but a possible association with hematologic malignancy was observed.