Doctors who perform colonoscopies for early detection of colorectal cancer were almost four times as successful when they took longer to evaluate a patient's colon, as they were more likely to spot polyps, according to a study. The study included 12 experienced and board-certified gastroenterologists. They did 7,882 colonoscopies, 2,053 of them for patients who'd never had a colonoscopy done and in 501 patients whose first-time screening was done in less than six minutes.
In a colonoscopy, the doctor inserts a thin flexible tube with a tiny camera into the colon. The colonoscopy camera lets the doctor check the colon for abnormalities, including cancerous and pre-cancerous growths.
During the study the gastroenterologists kept track of the time for each exam and how many polyps they found. On an average, it took 7 minutes for a doctor to guide the colonoscopy device into the colon during the procedure, and another 6 minutes to withdraw it and evaluate the inside of the colon, during the withdrawal, for the presence of polyps.
They found that in all, cancerous or pre-cancerous growth was detected in 23.5 % of patients examined. But such growths were detected in only colonoscopies with a withdrawal time of less than six minutes.
'This basically reinforces and provides evidence for the quality recommendations that have already been made,' said Dr. Durado Brooks, director of colorectal cancer for the American Cancer Society.
This study clearly shows that six minutes is a critical point, and those patients who had less, had a strikingly low rate of adenoma [growth] detection, and there is at least a suspicion that the cancer detection rates would be lower,' he said.
'We think our data suggest that if the goal of colonoscopy is to detect and remove polyps, spending slightly more time in the procedure seems to translate into a better outcome for patients,' said study co-author Dr. Robert L. Barclay, a partner in Illinois-based Rockford Gastroenterology Associates.