Multiple Myeloma and Exposure to Pesticides: A Canadian Case-Control Study

Abstract

The objective of this study was to investigate the putative associations of specific pesticides with multiple myeloma. A matched, population-based, case-control study was conducted among men residing in six Canadian provinces (Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia). Data were collected on 342 multiple myelome cases and 1506 age and province of residence matched controls. Data were collected by mailed questionnaires to capture demographic characteristics, antecedent medical history, detailed lifetime occupational history, smoking history, family history of cancer, and exposure to broadly characterized pesticides at home, work, and practicing hobbies. Details of pesticide exposures were collected by telephone interview for those who reported 10 hours or more per year of exposure. Exposure to pesticides grouped into major chemical classes resulted in increased risk being detected only for carbamate insecticides [odds ratio (OR) and 95% confidence interval (CI) 1.90 (1.11, 3.27) adjusted for potential confounders]. An exposure to fungicide captan [2.35 (1.03, 5.35)] was positively associated with the incidence of multiple myeloma. While an exposure to carbaryl [1.89 (0.98, 3.67)] was associated with the incidence of multiple myelome with borderline significance. The authors further suggest that certain pesticide exposures may have a role in multiple myeloma etiology, and identify specific factors warranting investigation in other populations.

Glyphosate epidemiology expert panel review: a weight of evidence systematic review of the relationship between glyphosate exposure and non-Hodgkin’s lymphoma or multiple myeloma

“…The publication is related to the trans-Canada NHL study reported initially by McDuffie et al (2001) wherein there was a common control group for the study of several lymphopoietic cancers. Pahwa et al (2012) was updated by Kachuri et al (2013) and we defer consideration to that more recent publication. Kachuri et al (2013) presented a reanalysis and extension of Pahwa et al (2012) in which they excluded 149 (of 1506) controls who did not have an age match with the MM cases.…”

“…Pahwa et al (2012) was updated by Kachuri et al (2013) and we defer consideration to that more recent publication. Kachuri et al (2013) presented a reanalysis and extension of Pahwa et al (2012) in which they excluded 149 (of 1506) controls who did not have an age match with the MM cases. Kachuri et al utilized unconditional logistic regression to estimate ORs and presented analyses including and excluding proxy respondents (15% of controls and 30% of cases) and adjusting for smoking, which was associated with MM.…”

“…We excluded redundant publications (Cantor et al 1992;Nordstrom et al 1998;Hardell & Eriksson 1999;Pahwa et al 2012) in favor of more recent published analyses of the same subjects. This resulted in a final evaluative dataset of seven studies of glyphosate exposure and NHL (see Table 2) and four studies of glyphosate exposure and MM (see Table 3 The descriptive characteristics of each of these studies were examined for the likely presence or absence of validity concerns (see Table 4).…”

“…Taken at face value, the results provide evidence of a weak inverse association between risk of MGUS and glyphosate, though the exploratory nature of this study, the lack of adjustment for other pesticides in pesticide-specific analyses, the cross-sectional nature of the study, and the implied speculative hypothesis underlying the analysis (that pesticides might cause MM by causing MGUS first) limit conclusions that can be drawn from this work. Pahwa et al (2012) reported a trans-Canada, multi-center case control study regarding the relationship between pesticide exposures and MM. The publication is related to the trans-Canada NHL study reported initially by McDuffie et al (2001) wherein there was a common control group for the study of several lymphopoietic cancers.…”

Increased cancer burden among pesticide applicators and others due to pesticide exposure

“…Positive associations between the fungicide captan (OR, 2.35; 95% CI, 1.11-3.27) and the insecticide carbaryl (OR, 1.89; 95% CI, 0.98-3.67) and multiple myeloma were observed in a recent Canadian populationbased case-control study conducted among men in 6 Canadian provinces (ie, Quebec, Ontario, Manitoba, Saskatchewan, Alberta, and British Columbia). 186 The study consisted of 342 multiple myeloma cases and 1506 controls. Recent data have shown that multiple myeloma is consistently preceded by monoclonal gammopathy of undetermined significance (MGUS).…”