Colorectal Cancer Test: Colonoscopy or Fecal Blood Test?

Colorectal cancer screening: patients given a choice more likely to comply

A killer next only to lung cancer, colorectal cancer is the third most diagnosed in men and the second most diagnosed in women worldwide — with over 1.2 million new cases and 700,000 deaths estimated to occur yearly.

But it’s curable when detected early, and the two main screening methods — fecal occult blood test and colonoscopy — can detect the earliest signs. The problem is, too many of the people who have a high risk for the cancer are skipping the tests because of “squeamishness” and lack of awareness.

Now researchers from the University of Washington in Seattle say that people whose doctors let them choose between a colonoscopy or a fecal occult blood test were much more likely to get screened than people whose doctors told them to get a colonoscopy.

This suggests that people are more likely to get screened for colorectal cancer when their doctors take their preferences into consideration before recommending one test or another.

This also means that the current universal practice of doctors recommending a colonoscopy actually reduces adherence to colorectal cancer screening — especially among racial or ethnic minorities in the United States.

Those are the two main findings of a study done by the University of Washington’s Dr. John M. Inadomi, and his colleagues. The results of their randomized study are published in the April 9 issue of the Archives of Internal Medicine.

The study also describes how various racial or ethnic groups vary in terms of their adherence to colorectal cancer screening recommendations.

A colonoscopy involves inserting a tiny camera attached to a tube through the anus into the colon to examine intestinal walls for abnormal growths. A fecal occult blood test, in turn, is a stool test that measures the amount and characteristics of blood in a person’s stool.

Commenting on the research, Dr. Linda Rabeneck, vice president of prevention and cancer control at Cancer Care Ontario in Canada says, “The basic finding here is, when offered a choice, you not only get better screening participation, but also a significant proportion of people don’t choose colonoscopy.”

“There are a lot of factors that are associated with the choice of one test over another,” Rabeneck tells Reuters Health in an interview. “I think this drives it home in a very powerful way,” she says. For one, the report shows people have a lot of different preferences when it comes to picking a test, she adds. Dr. Rabeneck wasn’t involved in the research.

Specifically, the study showed that:
• When given a choice, 69 percent of people get screened for colon cancer within a year
• When their doctor recommended a colonoscopy, just 38 percent of people got one.
• When their doctor recommended a fecal blood test, 67 percent of people went out and got one.
• Overall, 31 percent of the people given a choice went with the colonoscopy, versus 38 percent for the fecal blood test.

Dr. Inadomi and his colleagues also say that by pushing colonoscopies, doctors may be missing out on a chance to get people screened — especially if patients belong to an ethnic or racial minority.

The findings show that when given the choice:
• White people overwhelmingly chose colonoscopy
• African-American, Latino, and Asian participants preferred the fecal blood test.

“So there’s a clear racial split,” Dr. Inadomi, chief of gastroenterology at the University of Washington and lead author of the study tells Shots, the health blog of the National Public Radio. He also notes that until now, most research on colon cancer screening had been done in whites.