OAKLAND, Calif., Jan. 27 (UPI) -- A large study conducted in California found a non-invasive home test to screen for colorectal cancer was sensitive enough to detect the disease, and people consistently used the test during a 4-year test period.
The fecal immunochemical test, or FIT, detects tiny amounts of blood in stool samples, which can indicate tumors and precancerous polyps. Doctors have been concerned the tests could become less effective over time, however the new study showed that not to be the case.
The test requires people collect a small sample of their own stool and mail it to a lab, which tests for human blood from the lower intestines. Although larger tumors and polyps are known to leak blood into stool, the multi-year study showed the test is sensitive enough to pick up the slightest trace of blood in a sample.
Colorectal cancer is the third most common cancer diagnosed in the United States and kills 1 out of every 7 people diagnosed, though researchers have said improving screening rates in order to save more lives has been difficult.
Colonoscopies can be uncomfortable for patients -- requiring powerful laxatives to prepare for the test, and then the insertion of a camera into the colon. Doctors note one benefit of colonoscopy is the ability to have any polyps removed immediately if they are found, which is impossible with the home test. The FIT test is also better than another similar test, fecal occult blood test, or FOBT, based on the study results, researchers said.
"It doesn't require dietary changes or medications," Dr. Alok Khorana, an oncologist at Cleveland Clinic, told CBS News. "Logically, it's a little bit easier and does have a higher detection rate than the FOBT. It's been frustrating for physicians. Data shows that colon cancer screening saves lives."
In the study, published in Annals of Internal Medicine, researchers at Kaiser Permanente, a managed care company, collected data on 323,349 of its members between ages 50 and 70 who received and completed their first FIT in 2007 or 2008, about half those who were invited to participate.
Participants were followed up with for four annual rounds of home screening. While participation did drop off, it remained high, with 75 percent to 86 percent participating in subsequent years.
In the first year, the test detected colon cancer in 84.5 percent of participants who had been diagnosed with the disease. In years two through four, the test picked up between 73 and 78 percent of cancers.
Currently, colonoscopies are advised every 10 years, and are thought to be nearly 100 percent effective at detecting cancer and polyps, however the procedure is not preferable for all patients. Because it appears an annual FIT test may be as effective as colonoscopy, the at-home test could save more lives, researchers said.
"You end up getting more people screened, because it allows people to select what works the best for them," Dr. Douglas Corley, a research scientist with Kaiser Permanente, told HealthDay.