That’s the bad news. The good news is that colorectal cancer can be detected early with screening colonoscopy and, in many cases, prevented when pre-cancerous polyps are removed during the procedure.
Cortez family physician Jill Schenk, MD, received special training during her medical training to become proficient in performing colonoscopy. “For two months during my fellowship I did colonoscopies almost exclusively,” said Schenk. In her practice today, Schenk performs 10-15 of the procedures each month. “About 80 percent of my colonoscopy patients are women,” said Schenk.
“There are tests that have proven not to have a great track record for prolonging or improving life. The PSA test to screen for prostate cancer is one example,” says Schenk. Colonoscopy, however, is a screening procedure that has been proven in long-term, well-conducted scientific studies to detect cancer early and extend life. “It’s a powerful test that makes a big difference in people’s lives,” said Schenk.
Risk factors for colorectal cancer include a family history of gastrointestinal cancer, personally having had colon polyps in the past, having a diagnosis of inflammatory bowel disease, obesity, smoking, and a history of other cancers, particularly ovarian, uterine, breast, endometrial or prostate cancer.
Symptoms of colon cancer include blood in the stool (either bright or dark), weight loss, bowel changes such as very thin caliber stools, abdominal pain, and bloating. “It’s important to remember that early colon cancer often has no symptoms at all,” said Schenk.
While there are a variety of screening options available to detect colon cancer, colonoscopy remains the gold standard. “Patients often ask about alternatives such as mail-in testing of stool samples,” said Schenk. “The problem with this type of screening is that they miss polyps which can be pre-cancerous. And if there is evidence of blood in the stool sample the patient ends up getting a colonoscopy anyway.”
In addition, gastrointestinal bleeding can be intermittent and may be the result of problems other than cancer such as colitis, diverticulosis, or hemorrhoids. “I’ve had a couple patients who were certain their bleeding was due to hemorrhoids and they turned out to be right, but they also had cancer that was discovered when we did a colonoscopy,” said Schenk. The bottom line is that any evidence of blood in a bowel movement should be investigated by a physician.
Some of Schenk’s patients also ask about colon cancer screening by swallowing a tiny camera that passes through the gastrointestinal tract. This technology does exist, but it has imperfections, too. “You can’t go back and look a second time if you see something suspicious,” said Schenk. “When I do a colonoscopy I’ll often pass through sections of the colon multiple times just to be certain I have thoroughly examined every nook and cranny.” The camera method of looking for colon cancer also requires the same bowel prep (cleaning out the GI tract completely) before the procedure, which, for most people, is the most unpleasant aspect of colon cancer screening.
Schenk said that most of her patients report that having a colonoscopy is not nearly as bad as they feared it might be. “Anticipating the prep is worse than the actual prep, and patients are comfortably asleep during the 20-40 minute procedure and never remember a thing,” said Schenk. “I’ve started using a prep that’s a little gentler than previous ones. It’s not fun, but it’s not that bad.”
One new test that has been in the news recently is Cologard. This screening test is ordered by a physician. Then the patient obtains a stool sample at home and mails the sample to the company that invented the test. There it is screened for both blood and certain DNA biomarkers that may be indicative of colon cancer. “This is an additional tool to screen for cancer, but it doesn’t take the place of colonoscopy,” said Schenk.
Cologard, said Schenk, will likely be recommended every three years in people with no symptoms and no risk factors for colon cancer. Although approved for clinical use, Cologard is currently undergoing what’s known as the “comment period” at the FDA and it is, as yet, uncertain if Medicare will pay for the test and how frequently it can be ordered. The cost for this test is about $600 according to Schenk. “Cologard will detect 92% of actual cancers, but only 42% of aggressive pre-cancers,” said Schenk. “The jury is still out on this test,” she added. “It’s good at detecting cancer, but it’s not good at proving that cancer isn’t present.”
Early detection is the best defense against developing aggressive colon cancer, and colonoscopy is still the best screening mechanism available. “The wall of the colon is very thin. It takes just a few millimeters of cancer to eat through that wall and then the cancer can get into the lymphatic system and spread,” said Schenk. “I experience dread when someone comes to my office who has had bloody stools and weight loss over a period of months because there is a higher chance that a cancer is more advanced.”
Schenk recommends screening colonoscopy for all average-risk patients starting at age 50. “If you have the procedure and everything is fine, then you have peace of mind and don’t need another colonoscopy for ten years unless something with your health or family history changes,” she said.
Southwest Health Notes is a public service feature provided by Southwest Memorial Hospital in Cortez, Colorado. The information provided herein is not intended as patient-specific medical advice or as a substitute for consultation with your personal health-care provider.