Genetic-environmental interactions in relation to low dose studies: a possible model from breast cancer.

The identification of genetically susceptible individuals may permit the determination of genetic and environmental interactions which result in disease. This paper presents some recent findings on possible genetic-environmental interactions in breast disease as determined by a "nature-nurture" model employing epidemiological risk factors and cytologic studies of breast secretions obtained by nipple aspiration. The findings indicate that severe changes in the cytologic characteristics of the fluid are associated with a positive family history of breast cancer and clinical fibrocystic disease. These findings were interpreted as supporting the hypothesis that women with such a family history may have increased susceptibility to environmental factors. This model may have utility in other environmental epidemiologic studies.