Les origines du développement du cancer

The discovery of a rare clear cell carcinoma of the vagina in young women gestationally exposed to the estrogen diethylstilbestrol lent empirical support to the hypothesis that prenatal exposure to xenoestrogens might cause cancer. This fact contradicted two well-accepted notions: (i) mammalian development was merely the unfolding of a genetic program and (ii) only mutagenic agents could cause cancer. The ecological developmental biology (eco-devo) movement revitalized the concept of developmental plasticity through the occurrence of polyphenisms whereby a single genotype produces diverse phenotypes, which are determined by environmental cues. Based on the principles of eco-devo and the tissue organization field theory of carcinogenesis (TOFT), we hypothesized that developmental exposure to xenoestrogens increased the propensity to develop mammary cancer during adulthood. Emerging epidemiological data revealed an increased incidence of breast cancer in women exposed to DES during gestation. Hence, both animal experiments and epidemiological data strengthen the hypothesis that fetal exposure to xenoestrogens may be an underlying cause of the increased incidence of breast cancer observed over the last 50 years.