of the most hotly debated topics in health care is how often to screen for
different cancers. Current guidelines for colon cancer say it's okay to wait
for ten years between the screenings, known in the medical world as
colonoscopies. Some medical professionals and patients are calling for a change
in that schedule, but, as Rose Hoban reports, a new study indicates that it is
a reasonable guideline.
a colonoscopy, doctors insert a flexible probe with a very small camera into
the patient's colon to examine the intestinal wall. An independent panel of
experts in primary care and disease prevention has recommended that the
procedure be done every ten years.
some doctors and patients have insisted on more frequent colonoscopies, arguing
that ten years is enough time for dangerous cancers to develop. These people
have been pushing for guidelines calling for people to be screened more
of the reason for this push is that the screening guidelines were based on
evidence that isn't that strong, says Gastroenterologist David Ransohoff from
the University of North Carolina. "There hasn't been direct evidence where
people have been followed in large numbers, and followed intensely to learn,
after a negative colonoscopy, what's the chance that you get cancer in some
time afterwards?" he explains.
and his colleagues had an opportunity to answer that question. They accessed
data from a company that paid for its employees to get colonoscopies every five
years. Twelve-hundred people had the procedure.
that time, Ransohoff reports, none of these employees got cancer, or had any
evidence of cancer. He says these results strengthen the argument that a longer
wait between colonoscopies is probably safe.
results of this study suggest that the screening guidelines and policies that
we've got are now on stronger ground," Ransohoff says. He adds that it is
an important study because even though the finding is what people have
expected, this is the first time it has been documented by direct evidence in a
notes that in the United States, there's a tendency to want to use screening
tests too aggressively, and he points to the debate over prostate cancer
screening recommendations made recently by a government panel. He makes the
point that many of these screening procedures involve some risk.
though the complication rate of any one test is relatively small – one to two
in a thousand have a serious complication, like bleeding that needs a
transfusion, or perforation – if you do a large number of tests over 30 years –
say six, or ten – that adds up to a not negligible rate of complications,"
says he'll continue working to determine the most appropriate interval for
testing for this serious disease. His research is published in the New
England Journal of Medicine.