Feeding rats a high fat diet or the sex hormone oestradiol whilst pregnant leads to a higher susceptibility to carcinogen-induced breast cancer in offspring reports a study published in Nature Communications. These findings may have implications for the study of transgenerational inheritance of cancer risk.
It has previously been shown that exposure of pregnant rats to high fat diet, oestradiol, and other compounds increases the breast cancer risk of their female offspring. Sonia de Assis, Leena Hilakivi-Clarke and colleagues now show that this risk persists for two subsequent generations. After feeding pregnant rats with a high fat diet or oestradiol, the daughters were then mated to produce granddaughters and the granddaughters mated to produce great-granddaughters. The daughters, granddaughters and great-granddaughters were then treated with a carcinogen known to cause breast cancer in rats. The team confirmed previous findings and showed that daughters from high fat diet fed mothers were more susceptible to mammary cancer but also discovered that the granddaughters but not the great-granddaughters had a higher mammary cancer incidence compare to control fed rats. The granddaughters of rats fed oestradiol showed no increase in mammary cancer incidence but the great-grandaughters had more tumours than the control rats.
However, these findings are difficult to extrapolate to humans due to the oral treatment of mice with a carcinogen to induce breast cancer.