EXPERIMENTAL-STUDY OF DIFFERENT HISTOLOGI C TYPES OF LUNG CANCERS AFTER IRRADIATION

Recent epidemiologic studies suggested that some types of carcinomas w ere preferentially induced in the lung by irradiation, whatever the mo de of exposure and the radiation quality. Since smoking and other envi ronmental airborne pollutants may be strong confounding factors in hum ans, we have investigated whether histological subtypes were dependent or not on the mode of exposure, in a large series of 9000 rats expose d to external and internal sources at high and low Linear Energy Trans fer. Despite comparable overall risk coefficients in rats and humans, our results show that histological types are influenced not. only by d ose but also by radiation quality and heterogeneity of dose delivering . We suggest that extrapolation from one group to an other take this i nformation in consideration.