sive evidence that therapeutic radiation can be carcinogenic and leukemogenic comes from studies of patients irradiated for ankylosing spondylitis, enlargement of the thymus, and pynecolo- gical disorders. In like manner, epidemiologic studies have shown that radiologists have an excess of leukemia when compared to other physicians. These epidemiologic studies document that radiation not only causes various forms of cancer but also causes cancer of a (radiation) specific histologic type. With regard to the benefits of cancer screening, early diagnosis and early medical treatment, the National Cancer Institute recently has reported major gains in survival. In fact, leukemia and breast cancer are among those sites of cancer showing the greatest gains in survival following therapy. In light of these facts and because cancer is the leading cause of death among the Marshallese, the health care plan for the Marshall Islands must include an intensive program of cancer control. This cancer control should include, as a minimum, the following elements: 1) <A Cancer Registry. Current estimates of morbidity and mortality in the Marshall Islands came primarily from hospital discharge and clinic sick call data. Efforts should be made to ensure complete reporting of all cancers. Only by such a registry system can the full -2-