抄録
Our COE program "International Consortium for Medical Care of Hibakusha and Radiation Life Science" was established in October 2002. This consortium is aiming at combining medical care based on epidemiological studies on these radiation victims with basic radiation biology. To understand radiation-induced "human" carcinogenesis either by low-dose or high-dose, we need a molecular epidemiology of those cancers with firm evidence of clinical epidemiology. Among the Atomic Bomb survicors, we are looking some important new findings that solid cancers seem to occur multiple in a single survivor, and recent observation suggests an increased incidence of myelodysplastic syndromes (MDS). MDS is a clonal disorder closely related to leukemia that appeared very early after the Bombings. Amazingly, cancer incidences for many different organs such as lung, stomach, colon, thyroid, bone marrow (MDS) and others, seem to be persisting over a half century after the Bombing. Multiple cancers in individual survivors are apparently increased in proportion to the distance from the hypocenter. MDS also seems to be almost two-fold higher in crude incidence among the proximately exposed group than the distally exposed. These cancer tissue and bone marrow samples are being intensively studied by using molecular technology to understand what kind of genetic abnormalities are actually induced by the radiation. Whether these genetic abnormalities can be explained by the findings of genetic instability induced by radiation is extremely important. Such basic researches are usually based on mouse experiments. We need to use human cells to fully elucidate true mechanism of radiation-induced human cancers including leukemia. To establish preventive medicine and better medical care for radiation-exposed victims our COE program will continue these molecular epidemiology and basic research on human cells.
