Scientists report advance in colon cancer gene search
A 10-year study involving thousands of Israeli Jews and Arabs, led by researchers from American and Israeli institutions, has yielded important new information in the search for the genes that make a person more likely to develop colon cancer.
In a paper to be published in the July issue of Cancer Biology and Therapy, the international research team reports finding a significant link between genetic variation in a single region of human chromosome 8 and the risk of colorectal cancer.
The link was found by detailed comparisons of genetic material from thousands of colon cancer patients and nonpatients.
In all, people who carry the specific genetic variation, called a marker, were found to be 23 percent more likely to have colon cancer than individuals without the marker. The researchers estimate that this single genetic variation might account for 14 percent of colorectal cancer cases in Israel, where colon cancer is the leading cause of cancer deaths. The specific marker is called the C allele of rs10505477.
Three other research teams report similar findings in the journal Nature Genetics, having simultaneously found their way to the same small area of chromosome 8, called 8q24, in the search for colon cancer genetic links. The fact that these studies were performed among other populations around the world suggests that this one genetic marker is highly influential across ethnic groups.
The Cancer Biology and Therapy paper is by an international group of scientists from the U-M Medical School and School of Public Health (SPH), the Catalan Institute of Oncology in Spain, the CHS National Israeli Cancer Control Center and Technionthe Israel Institute of Technology.
It's the product of an ongoing Michigan-Israel collaboration, the Molecular Epidemiology of Colorectal Cancer project, which for 10 years has searched for clues to colon cancer's genetic roots using samples from large numbers of people in Israel with known ancestral heritage.
The project is funded by the National Cancer Institute, with additional funding from the Irving Weinstein Foundation.
Dr. Stephen Gruber, co-leader of the Michigan-Israeli team and first author of the new paper, says the finding is particularly interesting when considered alongside recent discoveries.
"The same genetic region that predisposes to colon cancer has also recently been shown to be an important region predisposing to breast cancer and prostate cancer," he says.
Gruber is an associate professor of internal medicine and of human genetics in the Medical School, and of epidemiology in the SPH. He directs the Cancer Genetics program in the center
Genetic discovery in Israel through MECC has already proven highly informative.
While there is not yet a screening test for the genetic variation that was pinpointed in the study, Gruber and his co-authors emphasize that testing is available for other known genetic variations linked to colorectal cancer.
In addition to Gruber and Rennert, the paper's co-authors are Victor Moreno of U-M and the Catalan Institute of Oncology in Spain, Laura Rozek of U-M Hematology/Oncology, Hedy Rennert and Flavio Lejbkowicz of CHS National Cancer Control Center and Technion, Joseph Bonner, formerly of U-M and now at Michigan State University, and Joel Greenson, Thomas Giordano and Eric R. Fearon of the U-M Department of Pathology.