Myelodysplastic Syndrome (MDS)
About the Disease
Myelodysplastic Syndromes (MDS) are clonal diseases of stem cells characterized by single or multilinease cytopenia and various bone marrow abnormalities. Up to 35% of MDS patients progress to Acute Myeloid Leukemia (AML) within a few months of initial diagnosis and the MDS has sometimes been characterized as a preleukemic condition or simply "preleukemia."
Chemical Exposure Causes
In 1993, British researchers published a summary of occupationally-induced hematological diseases from cases reported to the Health and Safety Executive. Over almost a 3-year period, 201 men and 28 women diagnosed with occupational hematologic diseases were reported. Among these, 49 cases of MDS were reported - the largest number of any hematologic disease. Benzene was the most commonly reported chemical thought to be implicated in the pathogenesis of the patients' disease; benzene was implicated as the cause of occupational hematologic disease in 43 cases. Jacobs, A., et al., "Haematological Disorders and Occupational Hazards: A British Society for Haematology/Health and Safety Executive Study," Brit. J. Haematol. 84:555-557 (1993).
Many other chemicals have been linked to MDS, including organic solvents, pesticides, hydrocarbons and welding fumes.
Occupational Hazards and Exposure Hazards
Additionally, many studies have been performed on particular industries that have high rates of MDS among workers. For instance, in 1993 Italian researchers published the results of a case-control study of 50 acute myeloid leukemias (AML), 17 chronic myeloid leukemias (CML), 19 myelodysplastic syndromes (MDS), and 246 controls. Exposure to suspected leukemogenic agents was assessed blindly by an industrial hygienist. Increased risks were noted for mechanics, welders, electricians, and drivers among men. Nonsignificantly increased relative risks for benzene were detected for exposure to benzene (OR = 1.7) and petrol refining products (OR = 1.9), as well as polycyclic aromatic hydrocarbons and electromagnetic fields, in men. Of the 19 men with MDS, 1 had no occupational exposure, 5 were occupationally exposed to benzene, 2 were exposed to petrol refining products, 7 were exposed to polycyclic aromatic hydrocarbons, 6 were exposed to electromagnetic fields, 2 were exposed to welding fumes, and 2 were exposed to asbestos. Ciccone, G., et al., "Myeloid Leukemias and Myelodysplastic Syndromes: Chemical Exposure, Histologic Subtype and Cytogenetics in a Case-control Study," Cancer Genet. Cytogenet. 68(2):135-139 (1993).
Successfully Litigated Cases
In 1999, Metzger Law Group reached a settlement against Mobil Oil Corporation and Allwaste Environmental Services for $2,750,000 in the case of a young man who developed MDS, Robert Keaton v. Mobil.