Diets high in meats cooked by high-temperature techniques such as barbecuing and pan-frying, which produce carcinogenic compounds, may lead to an increased risk of renal cell carcinoma. As part of an MD Anderson Cancer Center study published online in the journal CANCER, researchers also discovered that individuals with specific genetic mutations are more susceptible to the harmful compounds created when cooking at high temperatures.
Renal cell carcinoma (RCC), the most common form of kidney cancer, is expected to be diagnosed in more than 60,000 new patients this year and kill approximately 14,000, according to the American Cancer Society. The incidence of RCC has been rising for several decades, and many suggest that a Western diet is partially to blame.
One of the proposed culprits of a Western diet is higher-than-average meat consumption, which has been linked to increased cancer risk. However, it has not always been clear why eating more meat elevates cancer risk, said Stephanie Melkonian, Ph.D., a postdoctoral fellow of Epidemiology and lead author of the study.
A possible mechanism could be ingestion of meat-cooking mutagens, harmful compounds created when the meat is cooked in certain way. Cooking meat at high temperatures or over an open flame is known to result in the formation of carcinogens, including 2-amino-1-methyl-6-phenyl-imidazo(4,5-b) pyridine (PhIP) and amino-3,8-dimethylimidazo(4,5-f) quinoxaline (MeIQx).
The kidney is a biochemically active organ responsible for filtering many harmful toxins from the body, and therefore it make sense to investigate the effects of dietary intake, including carcinogens, on kidney cancer risk, said Melkonian.
To better characterize factors contributing to kidney cancer risk, the researchers surveyed the eating patterns and collected genetic information from 659 MD Anderson patients newly diagnosed with RCC and 699 healthy subjects recruited from the community. Based on survey responses, the researchers estimated meat consumption and exposure to meat-cooking mutagens with the help of a National Cancer Institute database.
“We found elevated RCC risk associated with both meat intake and meat-cooking mutagens, suggesting independent effect of meat-cooking mutagens on RCC risk,” said Xifeng Wu, M.D., Ph.D., professor of Epidemiology and senior author of the study.
Specifically, the results show that kidney cancer patients consumed more red and white meat compared to healthy individuals. Additionally, the researchers identified a 54% increased risk associated with PhIP intake and a nearly twofold increase associated with MeIQx intake. This is the first study to identify an association between kidney cancer risk and dietary MeIQx.