Background Myelodysplastic syndromes (MDS) are a group of clonal hematologic disorders that result in ineffective hematopoiesis. Individuals with MDS have a high risk of progressing to leukemia, with approximately 30% expected to develop acute myeloid leukemia (AML). Benzene exposure is one of the few well-established risk factors for AML, and recent studies suggest it is also a risk factor for MDS. Exposure to other occupational and residential chemicals has been inconsistently associated with hematologic malignancies. In this analysis, we evaluated occupational and residential chemical exposures as risk factors for AML and MDS using population-based data. Methods AML and MDS cases were identified by rapid case ascertainment through the Minnesota Cancer Surveillance System (MCSS). Centralized pathology and cytogenetics reviews were conducted to confirm diagnosis and classify by subtypes. Controls were identified through the Minnesota State driver's license/identification card list. Chemical exposures were measured by self-report and included occupational and residential exposure to a variety of chemicals. Unconditional logistic regression with adjustment for age, sex, previous cancer treatment, income, and farm or rural residence was used to calculate crude and adjusted odds ratios (ORs) and 95% confidence intervals (CI). Smoking, obesity and physical activity were considered as potential confounders but did not change effect estimates by 10% or more. Results We included 265 MDS cases, 420 AML cases, and 1388 controls in this analysis. As expected, we observed significant associations between benzene and both MDS and AML (OR = 1.77, 95% CI 1.17, 2.67 and OR = 2.03, 95% CI 1.45, 2.83, respectively). Exposure to vinyl chlorides was associated with MDS (OR = 2.25, 95% CI 1.32, 3.81) but not with AML (OR = 1.36, 95% CI 0.83, 2.21). Exposure to fertilizers (OR = 1.70, 95% CI 1.11, 2.59), soot (OR = 2.64, 95% CI 1.59, 4.39), creosote (OR = 1.95, 95% CI 1.08, 3.51), inks, dyes and tanning solutions (OR = 1.63, 95% 1.02, 2.60), and coal dust (2.64, 95% CI 1.30, 5.39) were associated with AML, while no association was seen between any of these exposures and MDS (range ORs = 0.78-1.25). No significant associations were observed for occupational pesticide exposures in either group. Discussion These data confirm the importance of benzene as a risk factor for myeloid malignancy and provide risk estimates in a population-based sample. A number of other significant associations with occupational and residential chemicals were observed for AML; however, all exposures were reported by only a small percentage of cases (≤10%). While chemical exposures play a clear role in the etiology of myeloid malignancy, these exposures do not account for the majority of cases.

Citation Format: Jenny N. Poynter, Michaela Richardson, Michelle Roesler, Cindy K. Blair, Betsy Hirsch, Phuong Nguyen, Adina Cioc, James R. Cerhan, Erica Warlick. Chemical exposures and risk of acute myeloid leukemia and myelodysplastic syndromes in a population-based study. [abstract]. In: Proceedings of the 107th Annual Meeting of the American Association for Cancer Research; 2016 Apr 16-20; New Orleans, LA. Philadelphia (PA): AACR; Cancer Res 2016;76(14 Suppl):Abstract nr 3427.