The NTP has found that 13 out of 14 brominated chemicals evaluated in two-year studies were carcinogenic in rodents. Common sites for chemical-related cancer included the oral cavity, forestomach, intestine, lung, and kidney. Most of these chemicals are genotoxic, suggesting that genetic damage may be involved in the carcinogenesis process. One particular cancer with which brominated chemicals have been associated is colorectal cancer.
Colorectal cancer is a major cause of morbidity and mortality in the United States.
Three of the chemicals causing marked increases in colorectal cancer were brominated chemicals. The morphological characteristics of the colorectal epithelial tumors induced by these chemicals are similar to those observed in human colorectal cancer. Studies to understand the mechanisms involved in the observed carcinogenic responses are also important aspects of this program. J. Cancer Res. The range-finding studies have been completed.