The Colon Cancer, Prostate Cancer Link

THE FOLLOWING IS A REWRITTEN, RESUBMITTED ARTICLE THAT CONTAINS NEW INFORMATION.

Information in the July 8th online version of Nature Genetics showed a key change in DNA linked to prostate cancer was also implicated in colon cancer.

The researchers said risks to an individual who has the rs6983267 variant gene are comparatively small. Those with the variant gene, located in the DNA chromosome 8q24, have about a twenty percent higher risk of developing colorectal cancer than those who don't have the variant gene, they said.

The key word is "variant" which has its roots in "vary," --to change form, appearance, nature, or substance.

Approximately one half of all subjects studied in four separate research projects carried the variant gene. Because it's quite common it can impact a large percentage of the population.

One researcher said between four and nine percent of all bowel cancers may be traced to the variant gene. One group compared the genomes of approximately 7,500 colon cancer patients and 7,800 non-cancer controls.

A USC study showed the variant gene increasing the colorectal cancer risk by twenty-two percent. Prior studies have shown an increased risk for prostate cancer when the rs6983267 variant gene is present. The USC research included 1,800 cancer patients from varied ethnic and racial backgrounds and 5,500 healthy controls.

The percentage of risk of prostate and colorectal cancer did not change because of the person's sex, race, site of tumor, tumor stage, family history, smoking or drinking.

There seemed to be contradictions in the information. The researchers stated that race made no difference, then later said the variant gene was found more frequently in some ethnic groups than in others. "The frequency of this specific genetic variation varies widely in the population, from about 85 percent of African-Americans to as low as 30 percent of Japanese." Simple math tells us the eighty-five percent group has a higher risk factor in their ethnic grouping than the thirty percent group.