Study on statistical theory of carsinogenesis model and its application to data in radiation epidemiology

点击翻译按钮获取中文摘要

The purpose of this study is to develop a statistical methodology for clarifying the mechanism of carsinogenesis induced by radiation. We used the mortality among atomic bomb survivors followed-up by Research Institute for Radiation Biology and Medicine, Hiroshima University and investigated the results from the radiation-epidemiological and radiation'biological point of view. In 2000, as one of the genetic instability model we proposed a protract effect model for radiation exposure based on the two-mutation clonal expansion model developed by Dr. Moolgavkar. In the protract model, changes of stem cell during a certain period after the exposure was considered. We visited Dr. Moolgavkar (FHCRC, USA) and he reviewed our study. Results for cancers of lung, stomach and colon were presented in the International Workshop on Mathematical Modeling in Carcinogenesis (Kyoto). In 2001, we reconsidered mathematical specification for the sporadic effect of the carcinogenesis model and discussed this problem with Dr. Moolgavkar again. In 2002, we analyzed the dose response curve for radiation and its possible threshold. We found a hockey-stick type curve in male lung cancer and a relatively high risk in low dose range in female lung cancer. When we combined these two heterogeneous curves, a linear dose response were appeared in lung cancer. We presented epidemiological findings in The XVI IEA World Congress ofEpidemiology (Montreal, Canada) and published a paper in the journal.