While blacks who have an increased chance of developing colon cancer continue to lag behind their white counterparts in colonoscopy rates, the lack of a doctor referral stood out as the primary reason why high-risk patients of either race had not been screened.
For people who have close relatives that have been diagnosed with colon cancer, the recommended screening is a colonoscopy every five years after the age of 40.
“People with a family history of colon cancer have a two to four times increased risk of developing the disease compared with people who don’t have such a history,” explained lead researcher Dr. Harvey J. Murff, an assistant professor of medicine at Vanderbilt University in Nashville, Tenn.
“When you look at people who have more than one close relative diagnosed with colon cancer, African-Americans were about half as likely to have reported undergoing the appropriately recommended screening as compared to whites,” Murff said.
The reasons for this disparity aren’t clear, Murff said. It could be that doctors don’t perceive blacks as having an increased risk for colon cancer, he speculated. It may also be that doctors are remiss in collecting a complete family medical history, he said.
“If providers aren’t aware of family history, they may be less likely to recommend the test,” Murff said. “There is a problem collecting family history and using it to risk-assess patients.”
Other conditions that limit access to care, such as not having health insurance or a usual care provider, may also play a role, Murff said.
The report was published in the March 24 issue of the Archives of Internal Medicine.
In the study, Murff’s group collected data on 41,830 people aged 40 to 79. Among these, 32,265 were black and 9,565 were white. The researchers specifically looked at how these patients were screened for colon cancer.
There were 538 blacks who reported having close relatives diagnosed with colon cancer, compared with 255 whites. Among blacks, 27.3 percent reported having a colonoscopy within the past five years, compared with 43.1 percent of whites.
The main reason for not having a colonoscopy among both blacks and whites was that their doctor had not recommended one. Among blacks, 59.3 percent said their doctor had not recommended a colonoscopy, compared with 51 percent of whites.
Doctors need to be sure that they get a complete family medical history, Murff said. “In addition, it is important for patients to know what your family history is, and if you have questions related to your family history or if you are concerned that it might impact your risk of disease, it is important to talk to your physician about it,” he said.