Processed Meat Elevates the Risk of Colorectal Cancer among Those with Genetic Variant

A large scale study discovered that consumption of red meat is tied to an increased risk of colorectal cancer and the risk is highest in the population carrying a genetic variant.

Researchers at the Keck School of Medicine of the University of Southern California reveal that a common genetic variant affects one in three people, which  also significantly elevates their risk of colorectal cancer due to consumption of processed red meat.

This study of over 18,000 people from the U.S., Canada, Australia and Europe is based on the genome-wide analysis of genetic variants and dietary patterns. Analysing these details offers an insight into the other contributing risk factors for colorectal cancer.

"Our results, if replicated by other studies, may provide us with a greater understanding of the biology into colorectal carcinogenesis," Dr Ulrike Peters of the Fred Hutchinson Cancer Research Center's Public Health Sciences Division, said in a statement.

The study included over 9,287 people who reported having colorectal cancer. The study also included a total of 9,117 healthy controls.  They were a part of the 10 observational studies sponsored by the National Institutes of Health-funded Genetics and Epidemiology of Colorectal Cancer Consortium (GECCO) and Colorectal Cancer Family Registry.

They searched through 2.7 million variants to trace the particular variant tied with consumption of meat, fiber, fruits and vegetables.  They finally found a strong association between the genetic variant 'rs4143094' and 'processed meat'.

The variant 'rs4143094' was found on the same chromosome 10 region that includes GATA3. This transcription factor gene 'GATA3' was earlier tied to various forms of cancer.  The transcription factor encoded in this gene plays a crucial role in the immune system. 

Lead researcher Dr Jane Figueiredo suggests that the genetic locus interacting with the processed meat may have a biological significance. 

Colorectal cancer also called as bowel cancer or colon cancer occurs when tumors form in the lining of the large intestine. Found in both men and women, this disease is linked to both genetic and lifestyle factors that include diet.  Throughout the genome, there are at least 30 genetic susceptibility alleles highlighted for the cause of colon cancer.

It is not known how some food trigger activities of the genes. "The possibility that genetic variants may modify an individual's risk for disease based on diet has not been thoroughly investigated but represents an important new insight into disease development," said Dr Li Hsu, the lead statistician on the study.

Colon cancer affects more than 130,000 people in the U.S. every year. It is the second leading cancer killer in the U.S. and it is the third most common cancer in men and women, according to the Centers for Disease Control and Prevention.

"Diet is a modifiable risk factor for colorectal cancer. Our study is the first to understand whether some individuals are at higher or lower risk based on their genomic profile. This information can help us better understand the biology and maybe in the future lead to targeted prevention strategies," said Dr Figueiredo.

The finding was published in the PLOS Genetics.