Colon cancer is America's third most common cancer, excluding non-melanoma skin cancer.
The disease often can be prevented if precancerous growths, called polyps, are removed in time.
Getting a colonoscopy or other colon screening allows your doctor to spot polyps and take them out of the colon or rectum before they become cancerous. Also, if screening shows cancer, early treatment increases the odds of survival.
For their study, Eugene Yoon, MD, and Mazen Jamal, MD, MPH, checked two national databases for new colon cancer cases reported from 1988 to 2002.
The researchers, who work at California's Long Beach VA Medical Center and the gastroenterology department of the University of California, Irvine, found that new cases of the cancer declined during that time - just as screening increased.
Then and Now
Here is a quick look at the study's findings.
One of the databases includes patients discharged from a national sample of U.S. hospitals.
It shows a drop in new colon cancer cases from 42.81 per 100,000 patients discharged in 1988-1990 to 38.59 in 2000-2002.
The second database tracks various types of cancer in the U.S.
It shows a drop in new colon cancer cases from 61.27 per 100,000 people, to 52.77 per 100,000 in 2000-2002.
Data for the colon cancer rates take patients' age into account, since colon cancer becomes more common with age.
At the same time, the researchers found that more people got colonoscopies from 1997 to 2003.
During that period, colonoscopy screening rates rose yearly, nearly doubling from 1997 to 2002, the study shows.
The CDC recommends regular screening starting at age 50. People at high risk for colon cancer may need to begin testing at an earlier age.
Here is an overview of colon cancer screening methods:
- Fecal occult blood test: Checks for blood in stool samples; given annually.
- Flexible sigmoidoscopy: Doctors use a thin, flexible, lighted tube to examine the rectum and lower part of the colon; done every five years.
- Double-contrast barium enema: Patient gets an enema containing barium dye, followed by X-rays of the colon and rectum; done every five years.
- Colonoscopy: Doctors use a thin, flexible, lighted tube to examine the rectum and entire colon; done every 10 years.
Though colon cancer screening is up, many people still aren't getting tested.
Ask your doctor if you are up to date on your tests.
SOURCES: American College of Gastroenterology's Annual Scientific Meeting, Las Vegas, Oct. 20-25, 2006. News release, American College of Gastroenterology. CDC: "Colorectal Cancer Screening Guidelines." WebMD Medical News: "More Americans Tested for Colon Cancer."
By Miranda Hitti
Reviewed by Louise Chang