Sara S. Strom, Ph.D.
Background: Myelodysplastic syndromes (MDS) are a diverse collection of blood disorders in which the bone marrow does not produce enough blood cells. Although MDS is not considered cancer, it is sometimes called preleukemia because some forms can progress to acute myeloid leukemia. Most MDS cases occur without apparent cause although some cases result from radiation and chemotherapy. Little is known about the causes of MDS; however smoking, exposure to solvents and pesticides, alcohol use, and genetic conditions have been shown to be associated with in MDS in some but not all studies.
MDS is increasing in incidence in the U.S., possibly due to the aging of the population and greater diagnostic awareness. A greater understanding of the causes and risk factors for MDS are necessary to develop preventive measures and therapeutic approaches for treating the illness. NIEHS-supported researchers at the M.D. Anderson Cancer Center in Houston, Texas, one of the largest MDS referral centers in the U.S., recently conducted a case-control epidemiologic study to investigate the association of lifestyle and demographic factors with risk of developing MDS.
Advance: The study examined 354 adult cases of MDS and 452 controls. As in some of the previous studies, family history of hematopoietic cancer, smoking, and exposure to agricultural chemicals and solvents were identified as independent risk factors for developing MDS. The results also indicate that the subgroup of cases with the type of MDS with the highest transformation rate to leukemia showed the strongest association with exposure to solvents and agricultural chemicals. Smokers who were also exposed to chemicals had over three times the risk of developing MDS as non-smokers without chemical exposure. This finding suggests an interaction between these two risk factors that should be considered when determining overall risk. The study also reports a protective effect of drinking wine.
Implications: This study suggests a variety of factors that may influence the development of the diverse types of MDS. The environmental exposures are common and their impact on the risk of MDS in the population as a whole may be significant. Overall the results suggest the origins of the disease are complex underlying the diversity of the conditions. The authors conclude that future studies should try to link exposures with specific types of MDS.
Citation: Strom SS, Gu Y, Gruschkus SK, Pierce SA, Estey EH. Risk factors of myelodysplastic syndromes: a case-control study. Leukemia. 2005 Nov;19(11):1912-8.