Researchers have discovered a genetic link between the risk for colon cancer and obesity, that could pave the way for greater accuracy in predicting those at risk for the disease.
“Adiponectin, called ADIPQ, a hormone secreted by the adipose [fat] tissue, has been genetically linked with colorectal cancer,” Dr. Boris Pasche, lead researcher and director of the division of hematology and oncology at the UAB Comprehensive Cancer Center.
“This is the first association to show genetic variants of a “fat hormone” can affect the risk of colorectal cancer,” he said.
The study, published in the Oct. 1 issue of the Journal of the American Medical Association, may help researchers to pinpoint those individuals who are at greater risk of developing colorectal cancer.
People, who have more of the hormone, typically have a lower risk of colon cancer, but the body’s mechanism for controlling adiponectin secretion by cells isn’t entirely clear.
The hormone represses inflammation of blood vessels, can increase the body’s metabolic rate, and is known to lower the risk of breast cancer and colon cancer.
Overweight people, who have a greater risk of cancer, typically have less of the hormone. While those people with more, have less risk of diabetes and heart disease.
Researchers examined ADIPOQ, a gene known to promote the formation of a fat hormone called adiponectin, for the study. They found, that people who inherit a typical variant of the gene have a 30 percent lower risk of developing colon cancer.
Conversely, researchers say that those people who do not have this variant or who have high levels may be at an increased risk of colon cancer and would most likely benefit from early screening.
“The findings add another piece to the puzzle and help us to better understand how genetics play a part in prostate cancer,” said Dr. Durado Brooks, director of colon and prostate cancer prevention programs at the American Cancer Society.
The study results illustrate one factor linking colon cancer and obesity, but no clinical application to this finding is expected in the near future, Brooks said. “I don’t think we would change our current recommendations, other than urging people that maintaining a healthy weight is best.
Tracing the genetic source of disease, such as cancer is still in its infancy, but offers great promise. Colon cancer is highly treatable, if caught early on, Dr. Pasche said.
According to the American Cancer Society, an estimated 149,000 Americans will be diagnosed with colon cancer in 2008 of which 50,000 will die from the disease. 1.2 cases are diagnosed globally each year.
Nearly one-third of all colon cancer cases are associated with family history and many genes that have been linked with the disease. For the most part, the genetic component is unknown.
An earlier British study found the more overweight you are, the greater your chance of developing cancer.
Reporting in The Lancet, the study says the weight issue relates to common cancers such as colon and breast but also to lesser known cancers such as gallbladder. #