A new study shows that patients are far less likely to undergo screening for colon cancer if their doctors recommend only colonoscopy, rather than offering other screening options.
The research suggests that offering patients at risk more choices might help increase the rate of testing for a disease that has long been associated with low screening rates. Survival rates for colorectal cancer are high when the disease is found early and treated, but nationwide, screening for the disease lags far behind that for breast and cervical cancers. Health authorities recommend that everyone be screened for colon cancer after the age of 50, or sooner in those who have additional risk factors, like a family history of the disease.
Colonoscopies are widely considered the gold standard when it comes to screening, but many patients fear the procedure and the bowel-cleansing preparation it requires, and many skip the test. Doctors rarely tell patients they have other options, like the fecal occult blood test, which is less accurate at detecting cancer but is far less invasive, requiring only that patients collect a tiny stool sample to be tested for traces of blood.
In the new study, published in Archives of Internal Medicine, researchers looked at what happened when roughly 1,000 people at moderate risk for colorectal cancer in the San Francisco area were given one of three screening options. In one group, doctors recommended only colonoscopy. In another, they offered their patients only a fecal occult blood test, requiring a stool sample. And in the third, they discussed with their patients both tests and gave them the option of choosing either one.
At the end of the study, the contrast among the groups was stark. When offered only colonoscopy, 38 percent of patients went through with screening. But nearly double the number of people went through with screening in the other groups – 67 percent of people in the group offered stool tests, and 69 percent in the group that was offered both options. The researchers noted, importantly, that a positive stool test was followed up by a colonoscopy to complete the screening.
Historically, most gastroenterologists prefer to offer only colonoscopies because they feel the other tests are inferior, but it is clear that many people would rather forgo screening altogether than undergo a colonoscopy, said the lead author of the study, Dr. John M. Inadomi, a professor and chief of the division of gastroenterology at the University of Washington. "I think what this shows is that patient preferences should be identified, because that's the way you're going to increase adherence to colon cancer screening," he said.
"No matter how effective we believe a colonoscopy is," he added, "if a patient doesn't do it, then it's not doing anything for them."
Health authorities say that as many as 60 percent of deaths from colorectal cancer could be prevented if everyone over 50 were screened regularly. And yet according to a large nationwide study in 2005, the most recent figures available, only half of adults over 50 reported that they had undergone a colonoscopy in the previous decade or a stool test with a home kit in the previous year. Screening rates are especially low among members of racial and ethnic minorities.
In the current study, roughly 60 percent of participants had completed screening after a year. Latinos had the highest rates of completion, at 63 percent, followed by Asians, at 61 percent. White patients were most likely to choose colonoscopy, whereas nonwhites showed a strong preference for the noninvasive stool test.
In an accompanying editorial, Dr. Theodore R. Levin, a gastroenterologist at Kaiser Permanente Medical Center in California, said the idea of a "preferred" screening test should not mean what doctors prefer, but what both doctors and their individual patients want.
