Doctors May Miss Second Colon Cancer
Feb. 19, 2002 -- A new study suggests that colon cancer patients may not be getting the best care possible. Researchers say that current care may allow a second colon cancer to grow unnoticed.
Colon cancer affects more than 130,000 Americans each year and is the second leading cause of cancer deaths in men and women. Once someone has been diagnosed with colorectal cancer, the chance of it recurring in them is higher than the chance of the average person getting it for the first time.
Currently, doctors usually perform a colonoscopy -- a procedure in which the inside of the colon is examined with a camera -- within one year after someone receives treatment for colon cancer. If that test is normal, the colonoscopy is repeated three years later. If normal again, the test is done every five years.
The problem with this schedule is it's not based on data from people with colon cancer but on people with polyps, or colon growths, who are more likely to get colon cancer. So researchers wanted to see if this was the best possible care for people already treated for colon cancer.
Lead researcher Robert J. Green, MD, and colleagues studied more than 3,200 people who had been treated for colorectal cancer. They wanted to see how many of them developed a second colorectal cancer and when the cancer was likely to recur.
The researchers found that 1.5% of people developed a second colorectal cancer over the next five years. On average, the second cancers were found about 18 months after the first cancer. But more than 40% were found more than two years after the original cancer.
Plus, the researchers found that many of the people developed cancer shortly after being checked out with a colonoscopy. Thus, the diagnosis was often missed until the person developed symptoms or had another colonoscopy.
The question is whether doctors should perform a colonoscopy more frequently to remove suspicious polyps, or growths, or catch cancers earlier.
The answer to that difficult question isn't known at this point. But since the frequency of repeat colon cancers seems to be higher than suspected, current testing schedules need to be re-examined, say the researchers.