American Cancer Society updates its colorectal cancer screening guideline
2018; Wiley; Volume: 124; Issue: 18 Linguagem: Inglês
10.1002/cncr.31742
ISSN1097-0142
Tópico(s)Colorectal Cancer Surgical Treatments
ResumoCancerVolume 124, Issue 18 p. 3631-3632 CancerScopeFree Access American Cancer Society updates its colorectal cancer screening guideline New recommendation is to start screening at age 45 years First published: 02 November 2018 https://doi.org/10.1002/cncr.31742Citations: 11AboutSectionsPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL The American Cancer Society (ACS) issued a new colorectal cancer screening guideline in May, advising that screening begin at age 45 years for individuals at average risk of the disease. The change from its previous guideline, which recommended that screening start at age 50 years, was prompted mainly by an increasing incidence of the disease among young and middle-aged populations. “We’re the first group to recommend that screening for everyone should start at age 45,” says Richard Wender, MD, chief cancer control officer for the ACS. “Over the past decade, we’ve seen a substantial increase in risk for the disease among people under age 50. The more recently you were born, the higher risk you have.” Published in CA: A Cancer Journal for Clinicians,1 the guideline recommends the following: Average-risk adults aged 45 years and older should undergo regular screening with either a high-sensitivity stool-based test or a structural (visual) examination, depending on patient preference and test availability. This change is designated a “qualified recommendation” because there is less direct evidence of the balance of benefits and harms or patients’ values and preferences among those aged 45 to 49 years. Screening in adults aged 50 years and older is designated a “strong recommendation” based on the strength of the evidence. Any of the screening options are acceptable. These include fecal immunochemical test (FIT) annually, high-sensitivity guaiac-based fecal occult blood test annually, multitarget stool blood DNA test every 3 years, colonoscopy every 10 years, computed tomography colonography every 5 years, and flexible sigmoidoscopy every 5 years. All positive results of non-colonoscopy screening tests must be followed up with a timely colonoscopy. Physicians should offer patients a choice between at least 2 screening options. Average-risk adults in good health with a life expectancy greater than 10 years should continue colorectal cancer screening through age 75 years. Whether to screen between ages 76 and 85 years should be based on patient preferences, life expectancy, health status, and prior screening history. Clinicians should discourage screening after age 85 years. In considering the evidence, the ACS, which last issued a full colorectal cancer screening guideline in 2008, strongly weighed the 51% increase in colorectal cancer incidence since 1994 among those individuals aged younger than 50 years. Death rates in this age group also have begun to rise. The authors note that the majority of that increase has been observed in cancers of the distal colon and rectum. A recent analysis has demonstrated that the risk of cancers of the distal colon was 2.6 times higher and the risk of cancers of the rectum was 4.1 times higher among individuals born around 1990 compared with those born around 1950. Risk Among Younger Adults Persists with Age Dr. Wender adds that studies indicate younger adults will continue to carry the elevated risk with them as they age. “We don’t know why the risk is increasing, but it’s virtually certain to be because of environmental factors,” he says. “It could be changes in our diet, lower physical activity, more stress, high obesity rates, or other factors we’ve not yet identified.” The ACS is encouraging more research into which factors could be contributing to the increase. Although the incidence rate for colorectal cancer among adults aged 45 to 49 years still is lower than it is among adults aged 50 to 54 years (31.4 vs 58.4 per 100,000 population), the higher rate in the latter group is partly attributed to the uptake in screening at age 50 years and the fact that adults in their 40s are far less likely to undergo screening. As a result, the true risk among adults aged 45 to 49 years is likely to be closer to that of individuals aged 50 to 54 years, the authors concluded. In addition, although the risk of the disease previously was higher among African American individuals compared with non-Hispanic white persons, the risks now are essentially the same, which is why the screening recommendation applies to everyone, Dr. Wender says. He notes that the risk for African Americans has remained relatively stable whereas it has increased among the white population. Because of the lack of large clinical trials examining the optimum age at which to start colorectal cancer screening, the ACS relied on 3 microsimulation modeling studies from the Cancer Intervention and Surveillance Modeling Network (CISNET) colorectal cancer group. Two of those microsimulation models, which were conducted for the 2016 US Preventive Services Task Force (USPSTF) screening recommendations, suggested that initiating colorectal cancer screening at age 45 years provided a slightly more favorable balance of benefits versus harms, but the USPSTF decided the benefits were modest and elected not to change the recommended screening age, according to Dr. Wender. However, realizing that these models were based on a population profile from the 1970s, the ACS team commissioned one of the studies to run the model again using an updated population profile from a more modern population. The analysis demonstrated that multiple screening strategies starting at age 45 years, including colonoscopy at the conventional 10-year interval, had a more favorable benefit-to-burden ratio with more life-years gained compared with starting at age 50 years. “If we start screening at 45, we’re optimistic we can turn that risk around in the 50- to 60-year-old age group,” Dr. Wender notes. The USPSTF, meanwhile, has no current plans to change its 2016 guidelines, which give an “A” grade to screening at age 50 years through 75 years and a “C” grade to screening from ages 75 to 86 years.2 “There aren’t any new trials that have come out since our recommendations were issued,” says Alex Krist, MD, MPH, vice chairperson of the USPSTF, noting that the microsimulation models incorporate assumptions to determine whether screening at specific ages saves the most lives while exposing patients to the least amount of risk. More Evidence Needed “The Task Force looked at not just the modeling data but also at primary studies, and we were concerned about being able to say with good certainty that we could get the same benefits in those age groups,” says Dr. Krist. “Our role is to say, ‘What do we know and what do we not know,’ and there are not many primary trials in younger patients, and we need to call that out.” The majority of the individuals in the trials examined by the USPSTF were aged 50 years or older, according to Dr. Krist, which is why the panel recommended the need for more evidence regarding screening in younger populations. “The Task Force is continually watching for new research that has been published, and I think this is an evidence gap that really deserves further study,” he adds. “We’re not saying don’t start at a younger age if you’re concerned. In general, we encourage people to talk with their clinician and then decide what’s right for them.” Dr. Wender says a randomized trial comparing screening at different ages has not been launched, could take years to generate results, and may never even occur. For those reasons and because of the increasing incidence rates among younger populations, the ACS’s guideline committee wanted to act soon. What both the ACS and the USPSTF do agree on is that undergoing any one of the approved colorectal cancer screening tests is better than having none at all. With only approximately 60% of the US population aged 50 to 75 years currently being screened, “the best test for a patient is the one they’re going to get,” Dr. Krist says. “We’re trying to focus our message on how important it is to get screened and that we have a number of good strategies,” he adds. Dr. Wender concurs, noting that each of the high-quality tests, if followed according to the guidelines, will prevent the same number of deaths. “We do call for offering choice because when people get a choice, they are more likely to do something,” he says. “The main choice we recommend is between colonoscopy every 10 years or the annual FIT.” References 1 Wolf AMD, Fontham ETH, Church TR, et al. Colorectal cancer screening for average-risk adults: 2018 guideline update from the American Cancer Society [published online ahead of print May 30, 2018]. CA Cancer J Clin. https://doi.org/10.3322/caac.21457. 2 US Preventive Services Task Force, Bibbins-Domingo K, Grossman DC, et al. Screening for colorectal cancer: US Preventive Services Task Force recommendation statement. JAMA. 2016; 315: 2564- 2575. Citing Literature Volume124, Issue18September 15, 2018Pages 3631-3632 This article also appears in:CancerScope Archive 2014-2019 ReferencesRelatedInformation
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