A CASE-CONTROL STUDY ON RISK-FACTORS FOR LEUKEMIA IN A DISTRICT OF JAPAN

A case control study was performed with 142 leukemia patients and 284 controls matched for age and sex. Occupation, birth order, past medica l history, and drinking and smoking habits were compared in these two groups. Persons born first or fourth were found to have a higher incid ence of leukemia. History of a fracture was one of the risk factors fo r acute leukemia, and a history of gastroduodenal ulcer was a risk fac tor for chronic leukemia. This may suggest that extensive exposure to X-rays in diagnosis and treatment is a risk factor for leukemia. There was a significant dose-response relationship between the amount of sm oking and the incidence of acute nonlymphocytic leukemia, but not betw een the amount of alcohol consumption and the incidence of leukemia. T hus, smoking was one of the risk factors for acute leukemia.