Organochlorine levels in plasma and risk of multiple myeloma

Abstract

Introduction: Multiple myeloma (MM) is a relatively rare cancer and little is known about its causes. Plasma levels of polychlorinated biphenyls (PCB) and organochlorine pesticides have been associated with increased risks of non-Hodgkin lymphoma and cutaneous malignant melanoma. There is very limited information regarding the association between these chemicals and the risk of MM, however, there is some evidence of an increased risk of MM in farmers related to exposure to organochlorine insecticides. The aim of this study is to investigate the association between plasma organochlorine levels and the risk of MM. Methods: A population-based case-control study was conducted in British Columbia (BC), Canada between 2009 and 2013. Cases were identified and recruited through the BC Cancer Registry, while age-group and sex-matched controls were randomly selected from the Consolidation File of the British Columbia Ministry of Health which contains identifying information on all participants in the population-based health insurance plan. 334 cases and 331 controls completed a computer-assisted telephone interview about environmental, lifestyle and medical factors, and provided a blood sample from which lipid adjusted levels of 14 congeners of PCB and 11 pesticides or pesticide metabolites were measured at the Centre de Toxicologie du Quebec. Initial analysis compared median analyte levels between cases and controls. Significance was assessed by the Mann-Whitney test. Results: MM cases had significantly higher levels of six PCB congeners and six pesticide analytes compared to controls. Conclusions: These initial suggest the possibility of an increased risk of MM with increased exposure to organochlorines. In order to confirm the associations, logistic regression models will be used to estimate the association between and the risk of MM adjusted for potential confounding factors including age, sex, education, BMI and weight loss.