Colonoscopy technology cuts need for polyp surgery, testing

Artificial intelligence is helping doctors distinguish in real time whether polyps, a telltale sign of colorectal cancer, are life-threatening or safe to be left alone, reducing the need for costly medical testing.

Researchers at the Digestive Disease Center at Showa University Northern Yokohama Hospital in Japan tested how a computer program designed to differentiate between dangerous or benign growths in the colon performed in real time compared with later laboratory testing, according to a study published Monday.

The program was able to confirm benign polyps 96 percent of the time with 94 percent accuracy, the researchers found.

All of the polyps were removed, but the Japanese researchers recommended that this technology could allow doctors to leave non-precancerous polyps alone, reducing time in removal and pathology testing.

Polyps are abnormal growths on a mucous membrane; in the colon, they could cause colon or rectal cancer. Yet certain characteristics such as size and texture indicate that a particular polyp is harmless.

Standard procedure for endoscopists is to remove all polyps discovered during a screening colonoscopy. A number of techniques have been devised to improve evaluation of polyps in the colon in an effort to reduce unnecessary procedures. But these methods, which include using colorful dye and high-magnification of polyp characteristics, showed little efficacy in accurate diagnosis, making total removal the safer option.

The latest research, published in the journal Annals of Internal Medicine, provides a technique to determine with high accuracy benign polyps, reducing the need for surgery and costly lab testing.

“This is a first iteration of really amazing technology,” said Michael Weinstein, assistant clinical professor of medicine at the George Washington University School of Medicine and Health Sciences, but who was not involved in the study. “Through advanced imaging, magnification and computer-aided analysis of the images, we are actually getting to the point where the computers can do the pathology before you even the remove the polyp.”

The researchers used high magnification and a computer algorithm to analyze polyps for precancerous signs during colonoscopies.

They assessed 462 polyps from 325 patients. Of those, 287 polyps were precancerous and 175 benign. The computer model predicted accurately 96 percent of the time. All results were confirmed by subsequent pathology testing.

The technology’s high efficacy in determining the difference in polyps has the potential to save tens of millions of dollars in extra medical procedures, an accompanying editorial in Annals pointed out.

“Leaving these polyps unresected would save time and expense; the annual cost of unnecessary polypectomy of hyperplastic [non-precancerous] polyps is estimated to be $33 million in the United States,” the authors wrote.

“That’s where this technology is headed,” Dr. Weinstein said. “Being able to aid the colonoscopist to analyze the polyp type even before it’s removed, so you know whether or not if you have to spend money in the laboratory, which is big. That’s potentially large savings.”

Colorectal cancer is the third most common form cancer for men and women. It is recommended that people have their first colonoscopy at age 50, although there is a debate among the medical community whether people should begin about five years earlier because of an increasing number of diagnoses among young people.

Since the mid-1980s, incidence of colon cancer in adults ages 20 to 39 has increased from 1 percent annually to 2.4 percent. For adults ages 40 to 45, cancer rates have increased from 0.5 percent to 1.3 percent since the mid-1990s, according to the National Cancer Institute.

More than 97,000 cases of colon cancer and more than 43,000 cases of rectal cancer are diagnosed in the U.S. each year, according to the American Cancer Society. An estimated 50,630 Americans will die of the disease this year.

“There’s an increase rate of colon cancer in the younger population, and colonoscopy is the best way to look for pre-cancerous polyps and to evaluate people with symptoms that are suspicious for cancer,” said Firas Al-Kawas, director of endoscopy at Sibley Memorial Hospital in the District of Columbia and a professor of medicine. He was not involved in the study.

Increased vigilance is key to early detection, Dr. Al-Kawas said. A family history of colorectal cancer and unexplained symptoms could indicate a problem. These include changes in bowel movements, either constipation or diarrhea, abdominal pain, blood in stool and unexplained weight loss.

“These changes should alert physicians to look for a cause, even though most people will not have cancer,” he said.