Does OTA affect cancer risk in laboratory animals?
Studies using laboratory animals tested the effects of OTA fed to rats and mice compared to animals fed diets with no OTA (controls). These studies show that OTA exposure causes tumors of the kidney in male and female rats and male mice and also mammary gland (breast) tumors in female rats. There is some evidence that OTA may cause liver tumors in female mice, but more data are needed to confirm this finding. The International Agency for Research on Cancer (IARC) has classified OTA as a “possible human carcinogen” based on these and other studies. Mammary Gland Tumors Two studies have demonstrated higher levels of mammary gland tumors in female rats exposed to OTA than in unexposed female controls. No mammary gland tumor data were reported for male rats in these studies. Kidney Tumors Several studies have shown that male mice develop kidney tumors after exposure to OTA in their diet. Most studies have not included female mice. In one study of both male and female mice, OTA caused kidne
