An average person has
about a 5% chance of
getting colon cancer,
and greater than 90%
of cases occur after age
50, which is why that’s
a good age for a first
“Colonoscopy is one of the few tests that prevents cancer.” Dr. Edward Slosberg, WWMG gastroenterologist, is that succinct when advising his patients who might be hesitant about getting screened for colon cancer.
In most cases, he explains, the predecessors to colon cancer are colon polyps, which grow very slowly, averaging about 1 millimeter a year. If they reach a size of about 10 millimeters, there seems to be a higher statistical risk of cellular change leading to cancer. Finding and removing polyps early cancels that possibility.
Someone with no family history of colon cancer, no previous history of colon polyps and whose screening is normal will most likely receive a 10-year clearance.
Of course, that decision “should be based on personal discussion between patient and physician, taking into account each patient’s circumstances.”
There are alternative screening options to colonoscopy, although Dr. Slosberg explains that, for various reasons, none is superior.
“For instance, the problem with relying only on fecal occult blood testing is that not all colon polyps will excrete blood,” says Dr. Slosberg. As for Barium enema, a pelvic x-ray test, “it needs to be complemented with sigmoidoscopy ( an exam used to evaluate the lower part of the large intestine ), and even then, we only give a five-year clearance.” And although CT colonography ( CT scanning to obtain an interior view of the colon ) “has a good role for patients who may need to avoid sedation,” it involves exposure to low-dose radiation.
“Colonoscopy allows us to do a more definitive examination and intervention. The value of the procedure is high, and the risks have gone down. Scopes and techniques have gotten better, and sedation is better managed. Whereas it used to be that you were the only person in a conversation who’d had a colonoscopy, you’re now the only person in the room who hasn’t.”
Still, Dr. Slosberg estimates that screening rates remain in the 50% range. “They should be higher. There’s little or no reason not to look, and
there are a lot of options to do so.”