With regard to the methods of early diaqnosis and medical treatment of cancer, The National Cancer Institute recently has reported major gains in survival. Specifically, leukemia and breast cancer are among those cancer sites which show the greater gains in survival following therapy. In light of these facts and because cancer is the leading cause of death amongst the Marshallese, the health care plan for the Marshall Islands must include an intensive cancer control program. This cancer control program should include, as a minimum, the following elements: 1. A Cancer Registry. Current estimates of morbidity and mortality in the Marshall Islands come 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 extent of cancer incidence and cancer control be fully evaluated. 2. Cancer Screening. this element should be directed toward the early diagnosis of radiation related cancer, i.e. breast, lung, lymohatic and thyroid cancer, as well as leukemia. In addition, the health care proposal must include a program of genetic screening. This should entail studies involving large scale genetic analysis of the Marshallese and also more diversified, specific studies of those exposed to radiation. Results from both of these efforts would contribute significantly to the interpretation