TUESDAY, Feb. 24, 2015 (HealthDay News) -- The area of the colon where a cancer develops may play a role in a patient's survival, a new study suggests.
Researchers report that people with colon cancer that started in the left colon may be more likely to survive than those whose disease originated in the right colon, researchers say.
A team led by Dr. Fotios Loupakis, of the University of Southern California Norris Comprehensive Cancer Center in Los Angeles, tracked data from three studies that included more than 2,000 advanced colon cancer patients.
The 70 percent of patients whose cancer began in the left side had a better survival rate than those whose primary cancer was on the right side, the researchers found.
Analysis of another study of 200 colon cancer patients yielded similar findings, according to the research published Feb. 24 in the Journal of the National Cancer Institute.
The results suggest that the "side of [colon cancer] origin could be of added value in clinical decision-making, and should be considered an important stratification factor for future randomized trials," the team concluded.
Writing in an accompanying journal editorial, Dr. Howard Hochster, of the Yale School of Medicine, said the findings are from patients with advanced colon cancer, and may not apply to those who have had surgery to remove primary tumors.
Two other experts unconnected to the study weren't surprised by the findings.
For example, studies have "been suggesting for some time that precancerous polyps that are found during colonoscopy also have a different distribution based on location," said Dr. Arun Swaminath, a gastroenterologist and director of inflammatory bowel disease at Lenox Hill Hospital in New York City.
However, he stressed that research in a set of patients followed prospectively over time may be needed to confirm the findings.
Dr. Jerald Wishner is director of the Colorectal Surgery Program at Northern Westchester Hospital in Mount Kisco, N.Y. He said the new findings are interesting, and might help doctors decide which colon cancer patients require post-surgical chemotherapy, and which do not.
"The location of the tumor has not previously played a role in this process," he noted. However, "this study opens up a potentially new avenue to peruse as we continue to narrow our treatment group -- maximizing the survival advantage while minimizing the treatment and exposure to the side effects of chemotherapy of patients who may not benefit."
The American Cancer Society has more about colon cancer.