Methods: The study population included 346 de novo MDS cases, 37 tMDS cases and 682 population controls frequency matched by age and sex. Polytomous logistic regression was performed to calculate odds ratios (OR) and 95% confidence intervals (CI).
Results: After adjustment, former smoking status (OR = 1.45, 95% CI: 1.10-1.93), personal history of autoimmune disease (OR = 1.34, 95% CI: 0.99-1.82) and exposure to benzene (OR = 1.48, 95% CI: 1.00-2.19) were associated with de novo MDS. Risk estimates for the associations between smoking, autoimmune disease, and benzene exposure were similar in magnitude but non-significant in tMDS cases. Among individuals with a previous diagnosis of cancer, de novo MDS cases and controls were more likely to have had a previous solid tumor, while tMDS cases more commonly had a previous hematologic malignancy.
Conclusions: We observed similar associations between smoking, history of autoimmune disease and benzene exposure in de novo and tMDS although estimates for tMDS were imprecise due to small sample sizes. Future analyses with larger sample sizes will be required to confirm whether environmental factors influence risk of tMDS.