Genetic Variant May Increase Colorectal Cancer Processed Meat Eaters

Colorectal cancer is one of the leading causes of cancer-related deaths in the United States. Now, new research, which has identified a link between a common genetic variant, dietary habits, and cancer risk, may help scientists develop targeted prevention strategies.

One in three people have this genetic variant, which appears to significantly boost the colorectal cancer risk associated with processed meat consumption, according to a report, published in PLOS Genetics.

Dr. Jane Figueiredo, Ph.D., co-author of the new study and assistant professor of Preventative Medicine at the Keck School of Medicine of USC, told Healthline, “People who have two copies of the variant allele appear to have a two-fold higher level risk of colorectal cancer if they consume large amounts of processed meat, compared to people who don’t have the variant.”

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Interaction Between Variant and Processed Meats

The new study is the first to explore colorectal cancer risk through a large-scale, genome-wide analysis of genetic variants and dietary patterns.The researchers pooled data from more than 18,000 participants in ten studies across North America, Europe, and Australia—including 9,287 participants with colorectal cancer and 9,117 control subjects.

“We combined their data on dietary intake and conducted genotyping for all participants, including cancer cases and matched controls,” said co-author Dr. Ulrike Peters, Ph.D., MPH, of the Fred Hutchinson Cancer Research Center. “We wanted to see if common genetic variants modify the dietary risk factors studied—including meat, red meat, processed meat, fiber, fruits, and vegetables.”

After assessing 2.7 million genetic variants, the researchers found a significant interaction between the variant rs4143094 and consumption of processed meat.

While the majority of participants in the study were of non-Hispanic, Caucasian descent, the researchers expect to find similar results among other members of the general population. However, there may be some differences among groups.

“This variant likely occurs in other ethnic-racial populations, but the frequency might vary,” suggested Dr. Figueiredo. “It may be more or less common in different populations.”

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In the study, Dr. Figueiredo defined “large amounts” as five or more weekly servings of processed meat, which includes hot dogs and some luncheon meats.

Although the new research findings may help experts develop targeted prevention strategies to help people who have a heightened risk of colorectal cancer, Dr. Peters cautioned that the researchers are still in the discovery phase of how genetics affect dietary risk factors for colorectal cancer. While he said it is too early for people to get genetic testing, she advised, "They should still reduce their intake of processed meat."

The American Cancer Society  (ACS) encourages people to limit the consumption of processed meat, red meat, and meat cooked at very high temperatures. The ACS advises consumers to eat plenty of whole grains, fruits, and vegetables, which may help to lower the risk of colorectal cancer.

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More Research Is Needed

According to the researchers, variant rs4143094 is located on the same chromosome 10 region as GATA3, a transcription factor gene that has previously been linked to several forms of cancer. “More research is needed to understand why this particular genetic change modifies the effect of processed meat,” said Dr. Figueiredo. “It’s very near to an interesting gene that’s involved in the immune system, and we speculate that may have something to do with it – but at this point, that's something we need to follow-up.”

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