Rectal cancer vs colon cancer

This article discusses why sigmoidoscopies miss many colon cancers, especially in women.
What I haven't found discussed much is the changing picture of colon cancer.
When I was in medical school in the 1960's, 80 percent of the colon cancers were in the last 20 inches of the colon, and 30 percent could be felt on a simple rectal examination...so we all learned to do sigmoidoscopies..

Back then, we used the old rigid sigmoidoscope, which was a 18inch tube about the size of a broom..ouch. The idea back then was to catch these early cancers. Some preventive medicine programs even screened everyone (mostly executive) every five years...

But then a funny thing happened. The American diet changed.
Dr. Burkett's observation that Africans with high fiber diets didn't get colon cancer or diverticulosis lead to the fiber craze... metamucil, here we come.

And gradually, we started seeing less rectal cancer and more colon cancer...

Medically this was good--the surgery was easier, and fewer required permanent colostomies (there are technical reasons for this but I'll spare you the details).

But it also meant that we now had to screen differently.
Colonoscopies, which use a flexible tube about a yard long, require much more skill than the simple sigmoidoscope, so need a specialist-- usually a doctor trained in internal (adult) medicine and gastroenterology (disease of the stomach and bowel)...or a surgeon.

As the article notes, if we were to screen everyone every 10 years, we would need 30 000 more docs to do just this....and even if we trained non doctors (such as specialized nurses or physician assistants) it would cost billions.

Another proposal is to do a single colonoscope at age 60...most colon cancers are over that age, and if you don't have precancerous polyps, you don't need another screen. However, colon cancer sometimes occurs in younger people...(Katie Couric's husband, for example)...so it misses the most tragic cases...

So the answer? Well, maybe a blood test. We thought the CEA test would do it, but alas it's not good enough.

We could screen those with symptoms. But most people have merely irritable colon..most colon cancer have no early symptoms, and by the time they have bleeding or symptoms the cancer is big.

So we are back to doing stool for occult blood. We send home cardboard packs and tell people: Place BM on two areas of the cardboard, three different days. No aspirin (causes blood). This picks up most, but not all of cancers. It also picks up precancerous polyps, which can be removed by colonoscopy. But it also picks up bleeding from the stomach (from aspirin, motrin, alcohol) and from hemorrhoids. So you end up doing a lot of unneeded colonoscopes.

Alternative is a sigmoidoscopy and a barium enema... which is what we did in the good old days and is still a good test. But the dirty little secret is that barium enema xrays are very unpleasant: I joke with my patients that when I have a patient I can't stand, I would send them for this test, and never see them again because they'd be mad at me for ordering the test. Colonoscopies are usually done with some anesthesia (enough to make you half asleep and pain free), so are much less painful...

What is the answer? Who knows...

Myself, I just do stool for occult blood every year.