Risk Factors for Leukemia Occurrence among Growth Hormone Users

A matched case‐control study on leukemia occurrence among growth hormone (GH) users was performed to elucidate any risk factor for leukemia. The total doses of GH and administration of other hormones, such as thyroxine, gonadotropin, gonadal hormones, glucocorticoid and anabolic steroid, did not lead to any apparent difference between cases studied and controls. Neither doses of diagnostic X‐rays nor therapeutic cranial irradiation was related to leukemia risk. Scintigraphy for thyroid function using radioactive iodide was the only significant risk factor (P=0.03). Hematological changes and liver function before and one month after GH administration were compared and the cases studied showed more proliferative reaction of white blood cells with rapid increase of neutrophils, but lymphocyte response was variable. Lactic acid dehydrogenase, alkaline phosphatase, glutamic oxalacetic transaminase, glutamic pyruvic transaminase tended to decrease after GH treatment when the patients had shown abnormally increased levels. Other environmental and familial factors did not show any abnormal clusters.