Screening colonoscopies performed by primary-care physicians under strict protocols are as safe and effective as those performed by specialists, according to a new study by researchers from the University of South Carolina’s Arnold School of Public Health.
In the largest published study on the topic in the United States, researchers found performance quality indicators and lesion detection rates in screening colonoscopies by primary-care doctors are comparable to documented rates for experienced gastroenterologists.
Colon cancer is one of the few preventable forms of cancer. A colonoscopy is considered the best test available to identify and prevent colorectal cancer. Primary-care physicians perform a small fraction of colonoscopies -- about 2 percent of those performed nationally in 2002 and 5.7 percent in South Carolina in 2005.
The USC researchers pointed out that the 10,958 colonoscopies by 51 primary-care doctors included in the study were performed under strict protocols to ensure patient safety. The tests were performed at a licensed ambulatory surgery center with specialists (gastroenterologists or GI surgeons) available in case there were technical difficulties in completing the procedure, in removing large polyps or in managing any major complications that can occasionally arise with this procedure.
The study’s results were published online in the journal, Medical Care. Funding for the study came from two grants from the National Cancer Institute along with USC’s Division of Health Sciences and the Center for Colon Cancer Research.
The findings are significant because there are not enough gastroenterologists to perform colonoscopies on everyone eligible to receive one. There is a 50-percent colonoscopy screening gap between those who have the procedure v. those who are eligible to be screened. That is attributed partly to the lack of specialists who perform the test, said Dr. James Hebert, professor of epidemiology and biostatistics in the Arnold School and director of the Cancer Prevention and Control Program at USC.
“We are short of gastroenterologists. We need at least three and a half times the current number of gastroenterologists to handle the backlog in South Carolina,” said Dr. Sudha Xirasagar, associate professor of health-services policy and management in the Arnold School and the study’s lead author.
During a colonoscopy, a doctor inserts a flexible, lighted tube into the rectum and guides it into the colon, looking for abnormalities or signs of cancer. The doctor may remove pre-cancerous growths, preventing cancer from occurring, and take tissue samples.
The USC study looked at colonoscopies performed at the S.C. Medical Endoscopy Center in Columbia. The colonoscopies were performed by a primary-care physician assisted by two technicians and a nurse anesthetist. A specialist was available on site. The study showed the colonoscopies met or exceeded the standards set by gastroenterologists.
The researchers emphasized that primary-care physicians must receive training from gastroenterologists or colorectal specialists to be competent and effective. They also must develop close partnerships with specialists and have specialized screening equipment and anesthetists available.
“These are replicable processes by which a patient may receive the same screening results with primary-care doctors if those doctors follow the specialists’ guidelines and receive specialist training,” Xirasagar said.
About colorectal cancer
The colon and rectum are part of the digestive tract and together make up the large intestine. Colorectal cancer (cancer of the colon or rectum) begins as a small growth in the lining of the colon or rectum. These growths may eventually form cancerous tumors capable of preventing digestion of foods and invading other organs. It is very expensive and painful to treat once symptoms appear. At later stages, the survival rate is poor. If untreated, colorectal cancers will lead to death.
Though about 90 percent of colorectal cancers are preventable using high-quality colonoscopy, these cancers represent the second-leading cancer killer in the United States. More than 90 percent of the cases of colorectal cancer occur in patients 50 and over.
During a colonoscopy, a flexible tube called the colonoscope is used to view the entire inner lining of the colon and the rectum. The scope allows the doctor to see the lining of the entire rectum and colon. Tissue samples of polyps and cancers can be taken. Most polyps can be removed during the test.