New Tests Ease the Colorectal Screening Process

Colorectal cancer screening tests may not be all that much fun … but new options now make these necessary tests more comfortable.

More than half of people who should be screened for colorectal cancer are not. Reasons vary, but the primary reason seems to be the inconvenience, followed by trepidation about discomfort or pain.

New colorectal screening tests and preps can help solve some of these problems and improve screening rates. However, some are not widely available, and none is good enough –- yet -- to replace the traditional colonoscopy.

Colorectal screening with FIT:
The most simple colorectal test -- one that doctors recommend be done yearly -- is the take-home fecal occult blood test (FOBT), for which you take a tiny swab from your feces for three bowel movements in a row. Yet studies show that nearly half of people who are offered this test never complete the FOBT or don’t turn it in.

Although it is not the most pleasant of chores, the reason most people give for failing to follow up on this colorectal screening test is the six days of drug and diet restrictions beforehand. These seem daunting, especially to health conscious people who follow diets high in prohibited foods such as raw fruits, vegetables, and vitamin C. Many said they found the dietary restrictions confusing or believed they had invalidated the test by not following the diet instructions.

A newer colorectal test, the fecal immunochemical test (FIT), doesn’t require any diet or drug restrictions. FIT is like FOBT without the hassle. You can skip dietary restrictions because it only detects human blood. It’s covered by Medicare and some insurers but is not offered everywhere, as it is somewhat more costly than the FOTB. Ask if it is available to you.

Colorectal screening with PreGen-Plus:
An even more promising new colorectal screening test can detect tiny bits of DNA shed from cancerous tumors or polyps into feces. Preliminary studies show this test to be much more accurate than the fecal blood tests in finding colon cancer, and it requires no dietary changes or other preparations. However, it does require an entire bowel movement to be captured, packaged, and shipped to a lab within 24 hours inside a cooler. At $500 a test, it is much more expensive than fecal blood tests, and is not covered by Medicare or most insurance carriers. This test has great promise, once the price and kinks are worked out. If you want to try it and pay for it yourself, ask your doctor about the PreGen-Plus test.

Colorectal screening with OsmoPrep:
A complete emptying of the colon is essential for a colonoscopy or other colorectal imaging tests, and many people find that one of the most unpleasant aspects of the procedure is the preparation: drinking a gallon of salty laxative, glass by glass, every 15 minutes for four hours. The salty fluid can be nauseating, even when it is flavored.

A new tablet preparation approved in March 2006 offers some improvement, because any clear liquid can be used and because it takes less time and less fluid.

A sodium phosphate laxative called OsmoPrep is given in 32 tablets, taken with a half gallon of any clear liquid in two sessions totaling two hours. Some tablets are taken the night before, and the rest three to five hours before the procedure. The pills are not yet available everywhere.

Colorectal screening with a virtual colonoscopy:
At first glance, the concept of a CT scan instead of one that involves internal scoping has great appeal, as there is no invasive procedure involved -- just a high-tech imaging procedure. However, most people don’t realize that it would still require the unpleasant preparation -- the purging of the bowels with laxatives after a period of eating a limited diet.

So far, the imaging test is not as accurate as a colonoscopy, and if polyps are found, a regular colonoscopy will be required, which doubles the cost and inconvenience of testing. One advantage: The test is noninvasive and thus removes the very small risk of a perforation during the exam. Colorectal cancer experts haven’t given this test their complete approval yet. It is still being studied.

Colorectal screening with robotic colonoscopy:
In development now is a self-propelled and self-navigating colonoscopy tool, which uses gentle air pressure to travel though the colon. An Israeli medical team that researched the device says it does not require sedation, is less likely to cause damage to the walls of the colon, and takes less expertise to operate. The device includes pressure regulators to ensure that air pressure stays within safe limits. However, the device doesn’t have the capacity to carry any instruments. So if a biopsy or polypectomy is necessary, a regular colonoscopy will have to be performed anyway.

Source: Johns Hopkins Medical Alerts 9/4/07