By Andrew M. Seaman
NEW YORK (Reuters Health) - An at-home test that reacts to blood in a person's stool can identify most colon cancers, according to a fresh look at some previous studies.
Researchers found the fecal immunochemical test (FIT) is able to detect 79 percent of colorectal cancers without making people change their diets or stop taking their medications, as some other screening tests require.
"It's more user friendly for the patient," Dr. Jeffrey Lee told Reuters Health.
Lee, from the University of California, San Francisco and Kaiser Permanente Northern California Division of Research, led the analysis.
Colon cancer is the second leading cause of cancer-related deaths in the U.S., according to the Centers for Disease Control and Prevention (CDC). About 132,000 people were diagnosed with the disease in 2010 and about 52,000 died from it.
The government-backed U.S. Preventive Services Task Force (USPSTF) recommends people between ages 50 and 75 get screened by colonoscopy every 10 years.
During a colonoscopy, a doctor uses a long flexible tube equipped with a tiny video camera to see the interior of the colon.
Alternatively, the USPSTF says people in that age group can have a high-sensitivity fecal occult blood test every year, or a sigmoidoscopy - which is similar to a colonoscopy - every five years in addition to fecal occult blood testing every three years.
Fecal occult blood testing (FOBT) is more cumbersome than FIT, Lee said. It requires more samples and more pre-test changes to a person's diet and medication schedule.
According to the USPSTF's website, the panel is currently planning to analyze the effectiveness of FIT.
For the new study, published in the Annals of Internal Medicine, the researchers searched databases of medical research for studies from 1996 through 2013 that looked at the effectiveness of FIT.
They included 19 studies in their final analysis. The studies each included between about 100 and 28,000 people with no symptoms of colon cancer.
In most cases, the participants used FIT and then were screened with a colonoscopy soon afterward.
The researchers found FIT detected 79 percent of colon cancers after one test. Among people who didn't have colon cancer, 94 percent tested negative.
For comparison, FOBT has a reported accuracy between 13 and 50 percent, according to the researchers.
While FOBT costs about $5 per test, the average cost of FIT is about $22, according to the patient advocacy organization Colon Cancer Alliance, Inc.
"Our study kind of confirms that FIT is an accurate test, but ultimately my take-home message is that there are so many options for screening," Lee said.
Janet Byron, a spokesperson for the Kaiser Permanente Division of Research, told Reuters Health in an email that Kaiser Permanente Northern California implemented systemwide FIT testing for adults between 50 and 75 years old. The kits are distributed by mail, at doctors' offices and in labs.
The healthcare system has a cancer screening rate of about 80 percent. That compares to the approximately 70 percent of people in that age range who are screened nationally, according to the CDC.
Assuming people use it, FIT could lead to a greater reduction in colon cancer deaths above what FOBT has already done, according to Lee.
"I just recommend that for the general population to get screened," he said. "The best test is the one that actually gets done."
(This version of the story corrects the percent of U.S. screened for colon cancer in paragraph 19.)
SOURCE: http://bit.ly/SQRXAa Annals of Internal Medicine, online February 3, 2014.