Can post-polypectomy surveillance be less intensive?
Authors: Sidney J Winawer, Ann G Zauber
Journal: The Lancet Oncology (2017)

Strong evidence from randomised trials in support of screening led to a consensus in 1997, which resulted in the publication of US guidelines recommending colorectal cancer screening.1Winawer SJ The history of colorectal cancer screening: a personal perspective.Dig Dis Sci. 2015; 60: 596-608Crossref PubMed Scopus (48) Google Scholar This recommendation resulted in an exponential proliferation of screening programmes with the subsequent identification of large numbers of patients with adenomatous polyps—the most common neoplastic outcome of screening—the removal of which reduces colorectal cancer incidence and mortality.2Zauber AG Winawer SJ O'Brien MJ et al.Colonoscopic polypectomy and long-term prevention of colorectal-cancer deaths.N Engl J Med. 2012; 366: 687-696Crossref PubMed Scopus (2038) Google Scholar The consensus was that, following polypectomy, patients should be placed under surveillance because they were considered to be at increased risk for subsequent adenomas and colorectal cancer.1Winawer SJ The history of colorectal cancer screening: a personal perspective.Dig Dis Sci. 2015; 60: 596-608Crossref PubMed Scopus (48) Google Scholar In the 1970s, it was common practice for patients to undergo colonoscopies every year after polypectomy. However, in 1993 the results of the randomised National Polyp Study (NPS) showed that the first follow-up exam can be deferred for 3 years,3Winawer SJ Zauber AG O'Brien MJ et al.Randomized comparison of surveillance intervals after colonoscopic removal of newly diagnosed adenomatous polyps. The National Polyp Study Workgroup.N Engl J Med. 1993; 328: 901-906Crossref PubMed Scopus (886) Google Scholar which led the US GI Consortium in 1997 to publish guidelines to recommend a 3 year interval for the first surveillance exam.1Winawer SJ The history of colorectal cancer screening: a personal perspective.Dig Dis Sci. 2015; 60: 596-608Crossref PubMed Scopus (48) Google Scholar In 2006, the US Multisociety Task Force (USMSTF) recommended risk stratification after polypectomy, with surveillance at 5 years for low-risk patients (those with one or two small tubular adenomas) and at 3 years for high-risk patients (those with adenomas ≥1 cm, high-grade dysplasia, or villous histology). A further shift towards less intensive surveillance was adopted in the 2008 USMSTF guidelines, which recommended a 5–10 year interval for low-risk patients.1Winawer SJ The history of colorectal cancer screening: a personal perspective.Dig Dis Sci. 2015; 60: 596-608Crossref PubMed Scopus (48) Google Scholar Guidelines were also developed by other organisations and in other countries. European Union (EU) and UK guidelines are consistent with the US guidelines with one exception.4Atkin WS Valori R Kuipers EJ et al.European guidelines for quality assurance in colorectal cancer screening and diagnosis. First Edition—Colonoscopic surveillance following adenoma removal.Endoscopy. 2012; 44: SE151-SE163PubMed Google Scholar The low-risk and high-risk groups are classified as low-risk and intermediate-risk and a third group is defined: a high-risk group of patients with five or more adenomas. With knowledge of the slow growth of the adenomatous polyp before it develops into colorectal cancer, guidelines have evolved to take a more conservative approach to surveillance, with increasingly longer intervals between examinations. The goal of surveillance is to reduce the risk of colorectal cancer and mortality in the group of patients at increased risk while minimising procedure risk, cost, and burden on medical resources. It is with these considerations in mind that Wendy Atkin and colleagues raised the question of whether surveillance intervals can be further modified in some patients after polypectomy. In The Lancet Oncology, Atkin and colleagues5Atkin WS Wooldrage K Brenner A et al.Adenoma surveillance and colorectal cancer incidence: a retrospective, multicentre, cohort study.Lancet Oncol. 2017; (published online April 27)http://dx.doi.org/10.1016/S1470-2045(17)30305-4Summary Full Text Full Text PDF PubMed Scopus (131) Google Scholar report a retrospective analysis of a large multicentre cohort study, in which 11 944 patients with adenomas deemed to be of intermediate risk according to the UK classification (US high-risk group) were followed up for a median of 7·9 years (IQR 5·6–11·1). A subset of these patients had an incidence of colorectal cancer that was significantly less than that of the general UK population not undergoing surveillance (standardised incidence ratio 0·51, 95% CI 0·29–0·84). Atkin and colleagues raise the question of whether surveillance was at all necessary in this group. The study by Atkin and colleagues is excellent, but has the limitations of a retrospective study, including the absences of bowel preparation reporting in line with current standardised criteria, central review of baseline pathology, information about the training, expertise, and adenoma detection rate of the endoscopists, criteria for a complete colonoscopy, and pathology of the proximal polyps. Prospective studies can address many of these limitations and can further examine the question of whether some patients really need surveillance and whether further lengthening of intervals can be recommended in others. Such studies can validate the evidence, which can inform guideline modifications. For example, in the EU and UK guidelines, can the lower-risk subgroup defined by Atkin and colleagues within the intermediate-risk group be relegated to receiving no surveillance, as they suggest? How can this approach be put into practice with clear terminology so that clinicians can easily separate out a lower-risk subgroup from this intermediate-risk group? Should the lower-risk subgroup be included in the original low-risk group? In the US guidelines, the recommendations for low-risk patients are for exams every 5–10 years. Could this recommendation be more definitively made 10 years? Can a subset of the US low-risk group be relegated to no surveillance? Can the intervals in US high-risk patients be lengthened to 5 years or could this group be further risk stratified? Within this context, much more information is needed on the natural history and follow-up of sessile serrated adenomas and polyps.6Rex DK Ahnen DJ Baron JA et al.Serrated lesions of the colorectum: review and recommendations from an expert panel.Am J Gastroenterol. 2012; 107: 1315-1329Crossref PubMed Scopus (814) Google Scholar New studies are being planned to address these questions, which are crucial given that post-polypectomy surveillance colonoscopies have become an increasing burden on endoscopy units, patients, the economy, and medical resources.7Jover R Bretthauer M Dekker E et al.Rationale and design of the European Polyp Surveillance (EPoS) trials.Endoscopy. 2016; 48: 571-578Crossref PubMed Scopus (79) Google Scholar Available colonoscopy resources might be better used if shifted to initial high-quality screening and diagnosis and will continue to be the driving force in the decrease in colorectal cancer incidence and mortality that has been ongoing since 1975.8Edwards BK Ward E Kohler BA et al.Annual report to the nation on the status of cancer, 1975–2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates.Cancer. 2010; 116: 544-573Crossref PubMed Scopus (1510) Google Scholar This will take on more urgency as worldwide colorectal cancer screening continues to accelerate, as has happened in the EU, the USA,8Edwards BK Ward E Kohler BA et al.Annual report to the nation on the status of cancer, 1975–2006, featuring colorectal cancer trends and impact of interventions (risk factors, screening, and treatment) to reduce future rates.Cancer. 2010; 116: 544-573Crossref PubMed Scopus (1510) Google Scholar, 9Meester RGS Doubeni CA Zauber AG et al.Public health impact of achieving 80% colorectal cancer screening rates in the United States by 2018.Cancer. 2015; 121: 2281-2285Crossref PubMed Scopus (152) Google Scholar and elsewhere. The study by Atkin and colleagues is provocative, calling attention to this important issue. We declare no competing interests. This publication was mainly funded by the National Cancer Institute with grants P30 CA008748, U01CA152959, R01 CA026852, R01 CA079572, and with additional support from the Cantor Colon Cancer Fund to SJW and AGZ. The views and opinions expressed therein are those of the authors and do not necessarily reflect those of the NCI. Adenoma surveillance and colorectal cancer incidence: a retrospective, multicentre, cohort studyColonoscopy surveillance benefits most patients with intermediate-risk adenomas. However, some patients are already at low risk after baseline colonoscopy and the value of surveillance for them is unclear. Full-Text PDF Open Access