Wednesday, February 2, 2011
Occupational Benzene Exposure and Lymphoma Subtypes
Previous studies on the possible association between benzene exposure and lymphoma have been complicated by problems with exposure misclassification, outcome classification, and low statistical power. Vlaanderen et al. (p. 159) performed a meta-analysis of occupational cohort studies for five different lymphoma categories, including Hodgkin lymphoma (HL), non-Hodgkin lymphoma (NHL), multiple myeloma (MM), acute lymphocytic leukemia (ALL), and chronic lymphocytic leukemia (CLL). The authors report that meta-relative risks (mRRs) for MM, ALL, and CLL increased with better study quality. mRRs for NHL also increased, but the effect was less pronounced. No association was observed for occupational exposure to benzene and HL. The authors conclude that their meta-analysis supports an association between occupational benzene exposure and risk of MM, ALL, and CLL. The evidence for an association with NHL is less clear, but this is likely complicated by the etiological heterogeneity of this group of diseases. Further consideration of the association between benzene and NHL will require delineation of risks by NHL subtype.