Colonoscopy saves lives. Doctors protest questionable European study

A new European study made headlines this week, which seemed to question the efficacy of colonoscopy as a cancer screening tool. But American doctors say the study has big limitations. They cite more than a decade of research showing colonoscopy saves lives. lechatnoir/Getty Images Hidden caption Toggle caption lechatnoir/Getty Images A new European study that questions the efficacy of colonoscopy as a cancer screening tool made headlines this week. But American doctors say the study has big limitations. They cite more than a decade of research showing colonoscopy saves lives. lechatnoir/Getty Images A large European study published this week in the New England Journal of Medicine seemed to question the usefulness of colonoscopy in preventing colorectal cancer, the leading cause of cancer death in the United States. “In large studies, screening procedures have failed to prevent colon cancer deaths.” But that’s not all. Colonoscopy is a widely recommended tool for cancer screening, which involves inserting an endoscope into the colon to find and cut out potential cancerous tumors called polyps. Sometimes these slow-growing polyps (or adenomas) can turn into cancer, so by periodically monitoring and removing the polyps, this procedure serves as a screening tool for cancer and as an intervention to prevent the tumor from developing in the first place. Research dating back more than a decade has shown that colonoscopy can save lives. For example, a 2018 study by Kaiser Permanente found a 67% reduction in cancer mortality in those who had a screening colonoscopy. In contrast, the main findings of this week’s NEJM study found a just 18% reduction in colorectal cancer among thousands of men and women in Europe who were ‘invited’ to undergo colonoscopy. And, as some media reports have pointed out, the death toll reduction was too small to be statistically significant. Seems pretty disappointing, right? The problem with the study, however, is that the bigger picture is: More than half of study participants ‘invited’ to undergo colonoscopy did not show up for examination. “A colonoscopy will only be effective if the patient undergoes a colonoscopy,” says Bret Petersen, a gastroenterologist at the Mayo Clinic and president of the American Society for Gastrointestinal Endoscopy, a leading group of GI physicians. Peterson says it’s important to focus on the results of those who actually have the procedure. This was all about 42% of the participants who lived in European countries, including Norway and Poland. In fact, the risk of colorectal cancer was reduced by about 31% in this group who had colonoscopy. “And the death toll has dropped significantly, around 50 percent,” says Peterson. He countered a suggestion that a study published this week would question the effectiveness of colonoscopy. “Conversely, we don’t think there are any data that suggest that the data from this study are less valuable,” says Peterson. “According to currently available research, colonoscopy remains the gold standard for detecting and preventing colorectal cancer,” he says. Peterson’s group ASGE issued a statement supporting the claim that colonoscopy is “still the best and most proven way for patients to be screened for colorectal cancer.” American Cancer Society: ‘These results indicate the value of ongoing screening’ The American Cancer Society also gave weight to this study, noting that the number of participants who did not receive the procedure was high. “The value of screening is difficult to appreciate when the majority of people in the study have not completed the test,” says Dr. William Dahut, ACS’ chief scientific officer. He stresses a 31% reduction in risk among those tested. “These results indicate the value of continuous testing,” says Dahut. The ACS also says it’s important to consider that some of the study participants had a colonoscopy eight years ago, because study participants were screened between 2009 and 2014. The ACS statement concluded, “The time from polyp to cancer to death is almost always longer than this, requiring much longer follow-up.” Over time, the reduction in cancer or death may be greater. It is unlikely that the controversy generated by this study will lead to a change in US testing recommendations. “Prophylactic cancer screening is the best and most reliable way to save lives,” said Karen Knudsen, CEO of the American Cancer Society. ACS recommends screening for colorectal cancer for adults 45 and older. “There’s no reason to change that direction.” .” says Knudsen. Some doctors were quick to point out improvements in the methods used by endoscopists (doctors performing the procedure) compared to 2009, when the European study began. Douglas, research scientist and gastroenterologist at Kaiser Permanente. “The polyp detection rate is much higher than it was 10 to 15 years ago,” Corley said. He says the equipment is better and the preparation methods have improved (patients should fast and drink a laxative drink specially formulated to help clear the gastrointestinal tract before the procedure). Also, “doctors have better polyps detection and removal skills,” Corley says. So, if research is starting now, “the benefits we expect to find now will be higher.” Differences between the United States and Europe Colonoscopy is also uncommon in the European countries where studies have been conducted, and Bret Petersen says that some doctors performing the examination have not been able to identify the number of polyps that are considered an acceptable percentage. In the United States, “nearly 30% of endoscopists included in the NordICC trial did not meet the adenoma detection rate,” says Peterson. He says this raises questions about whether they were really “missing some lesion that would otherwise have been detected and removed.” The study’s lead author says he is aware of any criticisms of his paper. However, he disputed the idea that the endoscopist did not find the level of polyps expected. “In Norway and Poland, the two countries with the highest number of participants, the detection rate, a quality indicator for polyps, is 30%, well above the current good quality threshold,” said Dr. Dr. Michael Bretthauer, University of Oslo, Norway. In Sweden, the detection rate was much lower and there were fewer study participants. Because not many people have polyps in Sweden. “So I don’t think that argument is valid.” Bretthauer said the paper is of great interest because it challenges common American assumptions about how protective a colonoscopy can be. “I think our findings suggest that colonoscopy is not the magic bullet for colorectal cancer,” says Bretthauer. But he says the risk of death is reduced by up to 50%, so it’s still more beneficial than almost any other cancer screening tool. Another problem with the new study in Europe is that it is not designed to answer the questions many people have when trying to evaluate screening options. “There are many ways to screen for colorectal cancer,” explains Kaiser Permanente’s Corley. Because European researchers have only evaluated colonoscopy, their study does not provide a direct comparison to the stool-based home test, an increasingly popular alternative to a once-decade colonoscopy. Alternative screening tests for colon cancer The US Preventive Services task force typically includes home-do colonoscopy, sigmoidoscopy (a less invasive test to evaluate part of the colon), or stool-based testing. Various types of colorectal examination methods are recommended. It is mailed back to a laboratory looking for blood or abnormal cells in stool samples. “It’s unclear which of these methods is better than the other in reducing deaths from colon cancer,” says Corley. A stool immunochemical test called FIT can detect small amounts of blood in the stool and is usually done annually. Another option is a combination test like Cologuard, which can detect both blood and DNA changes that can result from cancerous or precancerous polyps in your stool. It is generally recommended that people who choose this option have an examination every three years. Kaiser Permanente’s patients more commonly opt for the FIT test. Sometimes the biggest hurdle is remembering the test. So Corley says Kaiser mails the stool-based test to the patient and then keeps in touch with the patient until the test is returned. Each screening approach has “pros and cons,” Corley says. If the stool sample test is positive, it may be better to have a colonoscopy and have the polyp removed. Colonoscopy carries small risks, including the risk of perforation or colon rupture, bleeding at the biopsy site (if your doctor removes a polyp or doing a biopsy), and potential side effects from sedation during the procedure. In general, “If you’re at high risk of colon cancer, especially if you have a close family member who had colon cancer at a young age, it’s a good idea to have a colonoscopy,” says Corley. she says If you’re not at high risk, you should choose a test that can be completed, whether it’s a colonoscopy or a less invasive and frequent stool-based test, he says. No matter which colon cancer screening method you choose, it’s important to track and get screened, Corley says. You can find Allison Aubrey on Twitter @AubreyNPR.
#Colonoscopy #saves #lives #Doctors #protest #questionable #European #study

Leave a Comment

Your email address will not be published. Required fields are marked *