Study Finds Possible Genetic Indicator of Colorectal Cancer

June 19 -- THURSDAY, June 18 (HealthDay News) -- Scientists say they may be moving closer to developing a genetic test for colorectal cancer that could indicate who needs a more advanced colonoscopy screening.

In a study released this week, an international team of researchers report that they've found a genetic red flag that indicates the presence of cancer more than half the time.

The research is in its preliminary stages. But "molecular genetics will likely be the future of colon cancer screening," predicted cancer specialist Dr. Jerald Wishner.

The American Cancer Society estimates that 106,100 new cases of colon cancer and 40,870 cases of rectal cancer are diagnosed in the United States each year. Nearly 50,000 people are expected to die of the diseases this year.

The death rate has been dropping over the past two decades, possibly as a result of better screening. But colonoscopies, which look for suspicious polyps, often miss tumors.

Among other things, colonoscopies might not detect small polyps, and their success depends on the skill of the person performing the procedure, said Wishner, director of the colorectal cancer program at Northern Westchester Hospital in Mount Kisco, N.Y.

There are other challenges. The cost convinces some people to avoid colonoscopies, and there aren't enough gastroenterologists to perform all that are necessary, said Dr. Scott Kopetz, an assistant professor in the Department of Gastrointestinal Medical Oncology at the University of Texas M.D. Anderson Cancer Center.

And, he said, people also avoid colonoscopies because of the inconvenience and discomfort.

Enter the idea of genetic screening, which could make colorectal cancer easier to detect by finding signs of the disease in the body's cells.

In the new study, published online June 17 in the Journal of the National Cancer Institute, researchers in the Netherlands, Belgium and the United States looked for genetic signs that appeared in cancerous colorectal cells and tissue but not in those from healthy people.