Benzene exposure and refractory sideroblastic erythropoiesis: is there an association?

The myelodysplastic syndromes (MDS) consist of a group of diverse hematological disorders that carry an increased risk of transforming into acute myeloid leukemia. They may appear de novo and without obvious cause (primary or de novo MDS) or be induced by certain mutagenic environmental or therapeutic toxins (secondary MDS). Excessive exposures to benzene are generally considered to be a potential environmental risk factor for both MDS and acute myeloid leukemia. However, such risk is unproven for each disease component within the MDS classification. A critical review of the refractory sideroblastic disorders strongly suggests that benzene exposure is not a potential cause of this distinct and still-evolving subset of MDS. The widely disparate nature of MDS suggests that epidemiologic studies can only provide meaningful data on associations and potential causation of its component syndromes by a disease-specific analysis, as is currently advocated for other hematological malignancies.