Colon Screening: 5 Things You Need to Know

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Colon cancer is one of the most preventable cancers—as long as you step up to be screened on schedule. As you ponder being tested, here are five things to consider:

1. Who, me? If you're 50 or over, yes, you! That's the general population for which some form of colorectal cancer screening is recommended. (Those at higher risk because of family history or other factors may be advised to start earlier.) That doesn't mean you must get a colonoscopy (more later on alternatives), but that procedure does have the advantage of being able to identify and remove precancerous polyps. It's considered the gold standard of colorectal cancer screening. If you're coming up on 50 and your doctor doesn't mention it, ask. If your colonoscopy comes up clean and you are at normal risk of the disease, most guidelines say you don't need to be screened again for a decade, says David Lieberman, head of gastroenterology at Oregon Health and Science University in Portland. Some doctors believe that interval needs to be shortened to catch particularly fast-growing cancers that may pop up in between screenings or to protect against lesions missed the last time around, Lieberman says, but he believes 10 years is adequate, given the evidence and resources available.

The U.S. Preventive Services Task Force said last fall that screening colonoscopies can cease to be routine after age 75 and that folks over 85 shouldn't have a colonoscopy at all. In both cases, the USPSTF was weighing the odds that a colonoscopy would catch a cancer and extend an older patient's life against the chance of a life-threatening complication. (Serious complications are generally very rare.) "I don't agree with that recommendation," says Lieberman, who says the most significant risk factor for colorectal cancer is age, and that risk doesn't plateau until about age 95. A healthy 75-year-old, he says, could live another 15 years and is likely to benefit, while an unhealthy 60-year-old might be too sick to risk the complications. "It's an individual decision based on risk and benefit," Lieberman says.

2. What if I dread the idea? There's no doubt about it: Many people are scared of colonoscopy. Those who haven't had the procedure before usually fear pain. But that's not usually a factor, since patients are almost always sedated. There are two options, says Steven Frank, staff anesthesiologist at Greater Baltimore Medical Center: conscious sedation, during which you can respond to commands but remember very little afterwards, or a deeper sedation that knocks you out entirely, which requires an anesthesia provider's services. Technically, there's a third option: no sedation at all. Some people like the idea of being able to chat with their doctor while being scoped and of being able to drive themselves home; they say the procedure is somewhat uncomfortable but not at all terrible. In Europe, going without sedation is fairly common, but it's probably going to remain a niche market here.

Those who have had a colonoscopy usually come to dread the bowel-cleansing prep more than the procedure itself. There's no way around it, so make sure you do it right the first time so your doctor can complete the procedure and have the best chance of finding lesions, especially the flat ones that can be harder to see.

3. What about the cost? If you aren't covered by insurance and have to pay the cost (which will vary depending on where you live and the provider) out of pocket, you're far less likely to get tested. "Insurance coverage is maybe the biggest predictor of whether an individual is screened," says Durado Brooks, director of prostate and colorectal cancers for the American Cancer Society. (New York City increased its screening rates by funding free or low-cost screenings.) Most insurers cover the procedure—it's required by law in about half the states (of course, you are subject to the usual deductibles, copays, and other rules of your plan). Some insurers have balked at paying for the deeper sedation, which is more expensive because it requires an anesthesia provider. So be sure to ask ahead of time whether there will be an anesthesiologist and, if so, whether insurance will cover it. Make sure he or she is in-network, if your insurer requires that for you to get the fullest reimbursement.

4. How do I pick a doctor? Some recent studies have suggested that colonoscopies aren't as accurate as previously thought at detecting polyps. That's not a reason to avoid one; doctors still say it's the most effective screening test we have for a common cancer (except for the Pap smear, for cervical cancer). It is a reason to make sure you get the best possible care, and that, says Brooks, means tracking your doctor's stats with at least as much attention as you pay to A-Rod's during September.

You want to know how many colonoscopies she performs—experts say at least five a week is a good rule of thumb. She should also be tracking how often she finds a polyp, says Brooks. "In a general screening population, that should be between 15 and 25 percent of the time," he says. You want to know how often she completes a full exam of the colon, as opposed to stopping short of the cecum, or the beginning of the large intestine. (That may depend on whether the bowel prep has been done correctly and complicating digestive conditions, in addition to the doctor's skill.) Anything less than 90 percent of the time is worrisome, Brooks says. Finally, ask how long, on average, she spends withdrawing the scope from the colon. Anything less than about six minutes means the doctor is more likely to miss lesions, he says. Your doctor doesn't know the stats or pooh-poohs your attempts to get them? Find another one.