Effectiveness of screening colonoscopy in reducing the risk of death from right and left colon cancer: a large community-based study

Abstract

ObjectiveScreening colonoscopy's effectiveness in reducing colorectal cancer mortality risk in community populations is unclear, particularly for right-colon cancers, leading to recommendations against its use for screening in some countries. This study aimed to determine whether, among average-risk people, receipt of screening colonoscopy reduces the risk of dying from both right-colon and left-colon/rectal cancers.DesignWe conducted a nested case–control study with incidence-density matching in screening-eligible Kaiser Permanente members. Patients who were 55–90 years old on their colorectal cancer death date during 2006–2012 were matched on diagnosis (reference) date to controls on age, sex, health plan enrolment duration and geographical region. We excluded patients at increased colorectal cancer risk, or with prior colorectal cancer diagnosis or colectomy. The association between screening colonoscopy receipt in the 10-year period before the reference date and colorectal cancer death risk was evaluated while accounting for other screening exposures.ResultsWe analysed 1747 patients who died from colorectal cancer and 3460 colorectal cancer-free controls. Compared with no endoscopic screening, receipt of a screening colonoscopy was associated with a 67% reduction in the risk of death from any colorectal cancer (adjusted OR (aOR)=0.33, 95% CI 0.21 to 0.52). By cancer location, screening colonoscopy was associated with a 65% reduction in risk of death for right-colon cancers (aOR=0.35, CI 0.18 to 0.65) and a 75% reduction for left-colon/rectal cancers (aOR=0.25, CI 0.12 to 0.53).ConclusionsScreening colonoscopy was associated with a substantial and comparably decreased mortality risk for both right-sided and left-sided cancers within a large community-based population.

Early Colorectal Cancer Detected by Machine Learning Model Using Gender, Age, and Complete Blood Count Data

“…In addition, specialty guidelines recommended earlier or more frequent CRC screening for members of high-risk population groups-hereditary CRC syndromes, individuals with first-degree relatives with CRC, and patients suffering from inflammatory bowel disease [2][3][4][5]. Research has demonstrated that compared with no endoscopic screening, receipt of a screening colonoscopy is associated with a 67% reduction in the risk of death from any colorectal cancer [adjusted odds ratio (aOR) = 0.33, 95% confidence interval (CI) 0.21-0.52] [8]. By cancer location, screening colonoscopy is associated with a 65% reduction in risk of death for right colon cancers (aOR = 0.35, CI 0.18-0.65) and a 75% reduction for left colon/rectal cancers (aOR = 0.25, CI 0.12-0.53) [8].…”

“…Research has demonstrated that compared with no endoscopic screening, receipt of a screening colonoscopy is associated with a 67% reduction in the risk of death from any colorectal cancer [adjusted odds ratio (aOR) = 0.33, 95% confidence interval (CI) 0.21-0.52] [8]. By cancer location, screening colonoscopy is associated with a 65% reduction in risk of death for right colon cancers (aOR = 0.35, CI 0.18-0.65) and a 75% reduction for left colon/rectal cancers (aOR = 0.25, CI 0.12-0.53) [8].…”

Colorectal Cancer Screening: Recommendations for Physicians and Patients from the U.S. Multi-Society Task Force on Colorectal Cancer

“…Within the serrated class, hyperplastic polyps are not currently considered precancerous, whereas sessile serrated polyps (SSPs; also known as sessile serrated adenoma) and traditional serrated adenomas are considered precancerous ( should consider choosing colonoscopy. Although no randomized trials of colonoscopy for screening have been completed, extensive evidence from adenoma cohorts ( 30,31 ), cohort studies on incidence and mortality ( 55,56 ), and case-control studies (57)(58)(59)(60)(61)(62)(63)(64) support the effi cacy of colonoscopy in preventing incident CRC and cancer deaths. One cohort study ( 56 ) and 3 case-control studies ( 58,59,64 ) were performed in screening populations.…”

“…Although no randomized trials of colonoscopy for screening have been completed, extensive evidence from adenoma cohorts ( 30,31 ), cohort studies on incidence and mortality ( 55,56 ), and case-control studies (57)(58)(59)(60)(61)(62)(63)(64) support the effi cacy of colonoscopy in preventing incident CRC and cancer deaths. One cohort study ( 56 ) and 3 case-control studies ( 58,59,64 ) were performed in screening populations. Reductions in incidence and mortality are approximately 80% in the distal colon and 40 to 60% in the proximal colon, at least in the United States and Germany ( 57,59,61,62,64 ).…”

“…One cohort study ( 56 ) and 3 case-control studies ( 58,59,64 ) were performed in screening populations. Reductions in incidence and mortality are approximately 80% in the distal colon and 40 to 60% in the proximal colon, at least in the United States and Germany ( 57,59,61,62,64 ). Furthermore, indirect evidence from randomized trials of fecal occult blood testing ( 65 ) and sigmoidoscopy ( 66 ), as well as studies showing highly variable cancer protection provided by diff erent colonoscopists ( 67,68 ), also supports a protective eff ect of colonoscopy against CRC.…”