HEMATOPOIETIC MALIGNANCIES AND RELATED DISORDERS AMONG BENZENE-EXPOSED WORKERS IN CHINA

Although the relationship between benzene and acute nonlymphocytic leu kemia (ANLL) is well established, most of the analytic cohort investig ations examining the relationship between benzene and hematologic neop lasms have evaluated only death certificates to validate diagnoses. In a follow-up study of 74,828 benzene-exposed and 35,805 non-exposed wo rkers in China, pathology reports, medical records, and/or histopathol ogic material were reviewed for all patients with hematopoietic malign ancies to ensure correct classification and to provide clinicopatholog ic descriptions. Eighty-two patients with hematopoietic neoplasms and related disorders were identified among benzene-exposed workers, inclu ding 32 cases of acute leukemia, 7-myelodysplastic syndrome (MDS), 9-c hronic granulocytic leukemia (CGL), 20-malignant lymphoma or related d isorder (ML), 9-aplastic anemia, and 5 others. Among the comparison gr oup, 13 hematologic malignancies were observed, including 6 patients w ith acute leukemia, 2-CGL, 3-ML, and 2 others. The hematopathologic ch aracteristics of the benzene-exposed ANLL cases resembled those follow ing chemotherapy or radiotherapy. ANLL in workers exposed to benzene m ay represent a distinct clinicopathologic entity, with characteristics similar to treatment-related ANLL, including a preceding preleukemic phase in some patients. Results in our series, one of the largest to d ate, al-so indicate that a greater diversity of hematalogic neoplasms is evident among benzene-exposed workers than previously described.