{"entity":{"id":"national-polyp-study","kind":"trial","name":"National Polyp Study","aka":["NPS"],"tldr":"The study that showed removing a polyp at colonoscopy does not just prevent cancer, it prevents death from it: half as many deaths as expected, fifteen years on.","summary":"The National Polyp Study followed 2,602 patients whose adenomas had been removed at colonoscopy. After a median 15.8 years, 1,246 had died of any cause and 12 of colorectal cancer, against 25.4 deaths expected from Surveillance, Epidemiology and End Results rates: a standardised incidence-based mortality ratio of 0.47 (95% CI 0.26 to 0.80), a 53 percent reduction. Mortality from colorectal cancer in the first ten years after polypectomy was the same as in the internal control group of people with non-adenomatous polyps. The study is the evidence that the adenoma-carcinoma sequence can be interrupted mechanically, which is the whole basis of colonoscopic screening and of the surveillance intervals that follow polypectomy.","status":"positive","asOf":"2026-09-24","links":[{"label":"National Polyp Study: colonoscopic polypectomy and long-term prevention of colorectal cancer deaths (New England Journal of Medicine 2012)","url":"https://doi.org/10.1056/NEJMoa1100370"}],"tags":[],"related":[],"cancers":["colorectal"],"sections":["early-detection","prevention"],"technologies":["colorectal-screening","endoscopic-resection"],"targets":[],"drugs":[],"companies":[],"institutions":[],"pathways":[],"terms":[],"trials":["nordicc","minnesota-fob"],"people":[],"bottlenecks":[],"keyPapers":[],"journals":[],"dependsOn":[],"notes":[],"phase":"observational","setting":"People whose adenomas were removed at colonoscopy: long-term colorectal cancer mortality against the general population and against people with non-adenomatous polyps","sponsor":"National Cancer Institute (US)","result":"Standardised incidence-based mortality ratio 0.47 (95% CI 0.26 to 0.80) after polypectomy, a 53 percent reduction in deaths from colorectal cancer.","yearReported":2012,"enrolled":2602,"enrolledBasis":"analysed","enrolledNote":"2,602 patients who had adenomas removed during the randomised surveillance study were followed for the long-term mortality analysis; the study began in 1980 and predates the registries.","outcomes":[{"endpoint":"Colorectal cancer mortality against the general population","primary":true,"unit":"standardised mortality ratio","arms":[{"name":"After colonoscopic polypectomy","n":2602,"value":0.47,"note":"12 observed against 25.4 expected deaths"}],"ci":[0.26,0.8],"source":"https://doi.org/10.1056/NEJMoa1100370"}],"replication":"NordICC, the first randomised trial of invitation to colonoscopy, found a smaller effect in intention-to-treat analysis because only 42 percent of those invited attended."},"route":"/trials/national-polyp-study/","neighbours":{"cancer":[{"id":"colorectal","kind":"cancer","name":"Colorectal cancer","route":"/cancers/colorectal/"}],"section":[{"id":"early-detection","kind":"section","name":"Early Detection & Screening","route":"/fronts/early-detection/"},{"id":"prevention","kind":"section","name":"Prevention & Risk","route":"/fronts/prevention/"}],"technology":[{"id":"colorectal-screening","kind":"technology","name":"Colorectal cancer screening (colonoscopy, FIT, stool DNA, blood)","route":"/technologies/colorectal-screening/"},{"id":"endoscopic-resection","kind":"technology","name":"Endoscopic resection (EMR / ESD)","route":"/technologies/endoscopic-resection/"}],"trial":[{"id":"minnesota-fob","kind":"trial","name":"Minnesota Colon Cancer Control Study","route":"/trials/minnesota-fob/"},{"id":"nordicc","kind":"trial","name":"NordICC (Nordic-European Initiative on Colorectal Cancer)","route":"/trials/nordicc/"}]}}