Association Between Colonoscopy and Colorectal Cancer Mortality in a US Cohort According to Site of Cancer and Colonoscopist Specialty

Keenan ResearchCentre, Li Ka Shing Knowledge Institute, andDivision of General Surgery, St. Michael's Hospital, University of Toronto, 30 Bond Street, Toronto, Ontario, Canada.
Journal of Clinical Oncology (Impact Factor: 18.43). 06/2012; 30(21):2664-9. DOI: 10.1200/JCO.2011.40.4772
Source: PubMed


We designed this study to evaluate the association of colonoscopy with colorectal cancer (CRC) death in the United States by site of CRC and endoscopist specialty.
We designed a case-control study using Surveillance, Epidemiology, and End Results (SEER)-Medicare data. We identified patients (cases) diagnosed with CRC age 70 to 89 years from January 1998 through December 2002 who died as a result of CRC by 2007. We selected three matched controls without cancer for each case. Controls were assigned a referent date (date of diagnosis of the case). Colonoscopy performed from January 1991 through 6 months before the diagnosis/referent date was our primary exposure. We compared exposure to colonoscopy in cases and controls by using conditional logistic regression controlling for covariates, stratified by site of CRC. We determined endoscopist specialty by linkage to the American Medical Association (AMA) Masterfile. We assessed whether the association between colonoscopy and CRC death varied with endoscopist specialty.
We identified 9,458 cases (3,963 proximal [41.9%], 4,685 distal [49.5%], and 810 unknown site [8.6%]) and 27,641 controls. In all, 11.3% of cases and 23.7% of controls underwent colonoscopy more than 6 months before diagnosis. Compared with controls, cases were less likely to have undergone colonoscopy (odds ratio [OR], 0.40; 95% CI, 0.37 to 0.43); the association was stronger for distal (OR, 0.24; 95% CI, 0.21 to 0.27) than proximal (OR, 0.58; 95% CI, 0.53 to 0.64) CRC. The strength of the association varied with endoscopist specialty.
Colonoscopy is associated with a reduced risk of death from CRC, with the association considerably and consistently stronger for distal versus proximal CRC. The overall association was strongest if colonoscopy was performed by a gastroenterologist.

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    • "Colonoscopy does not reduce the incidence of death caused by right-sided colorectal cancer [13]. However, recent studies showed that a long-term effect of colonoscopy and a modest risk reduction for proximal colon cancer was achieved by colonoscopy in a United States cohort [5,14] and German cohort [15]. Colonoscopy performed by a gastroenterologist was more protective against colorectal cancer mortality than was colonoscopy performed by other providers. "
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    ABSTRACT: Serrated lesions of the colorectum as categorized by pathology include hyperplastic polyps, sessile serrated adenomas without dysplasia, and traditional serrated adenomas with dysplasia. The aim of this study was to investigate the prevalence of various subtypes of serrated lesions by age. In this study, 28,544 consecutive asymptomatic patients (aged 22-88 years) were evaluated during health check-ups involving colonoscopies performed by gastroenterologists at a single institution from 2005 to 2012. The adenoma detection rate during colonoscopies for patients aged >=50 years was 31.8% (25.0-35.8%). The serrated lesion detection rate for patients aged >=50 years was 15.3% (10.5-19.6%). Serrated lesions were detected in 15.1% of all patients with subtype prevalences of 14.7% for hyperplastic polyps, 0.5% for sessile serrated adenomas, and 0.1% for traditional serrated adenomas. The prevalence of conventional adenomas increased sharply with age (5.0% in patients aged 20-29 years, 10.9% in those aged 30-39 years, 21.8% in those aged 40-49 years, 29.5% in those aged 50-59 years, 36.9% in those aged 60-69 years, and 40.7% in those aged >=70 years) (trend P = 0.027). In contrast, the prevalence of serrated lesions increased only slightly with age (10.0% in patients aged 20-29 years, 11.8% in those aged 30-39 years, 14.8% in those aged 40-49 years, 15.3% in those aged 50-59 years, 16.8% in those aged 60-69 years, and 16.4% in those aged >=70 years) (trend P = 0.036). The screening colonoscopy detection rate of serrated lesions, including sessile serrated adenomas and traditional serrated adenomas, appears to be relatively high among young patients aged <50 years.
    Full-text · Article · Apr 2014 · BMC Gastroenterology
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    • "However, colonoscopy is not a perfect test; population-based studies suggest that colonoscopy can miss cancerous lesions in 2%–6% of exams [11–14]. Furthermore, recent studies have underscored the limitation of colonoscopy in preventing CRC, especially on the right side of the colon [8, 15, 16]. "
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    ABSTRACT: Background. Quality indicators for colonoscopy have been developed, but the uptake of these metrics into practice is uncertain. Our aims were to assess physician perceptions regarding colonoscopy quality measurement and to quantify the perceived impact of quality measurement on clinical practice. Methods. We conducted in-person interviews with 15 gastroenterologists about their perceptions regarding colonoscopy quality. Results from these interviews informed the development of a 34-question web-based survey that was emailed to 1,500 randomlyselected members of the American College of Gastroenterology. Results. 160 invitations were undeliverable, and 167 out of 1340 invited physicians (12.5%) participated in the survey. Respondents and nonrespondents did not differ in age, sex, practice setting, or years since training. 38.8% of respondents receive feedback on their colonoscopy quality. The majority of respondents agreed with the use of completion rate (90%) and adenoma detection rate (83%) as quality indicators but there was less enthusiasm for withdrawal time (61%). 24% of respondents reported usually or always removing diminutive polyps solely to increase their adenoma detection rate, and 20% reported prolonging their procedure time to meet withdrawal time standards. Conclusions. A minority of respondents receives feedback on the quality of their colonoscopy. Interventions to increase continuous quality improvement in colonoscopy screening are needed.
    Full-text · Article · Mar 2014 · Gastroenterology Research and Practice
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    • "Screening colonoscopy has persisted for decades in a similar limbo state, without definitive mortality evidence in its support, and with recent studies questioning its use. The study by Baxter and colleagues [Baxter et al. 2012] offers the first definitive evidence of superior efficacy, with mortality reduction throughout the colon, making ongoing efforts to promote colonoscopy appropriate. "

    Preview · Article · May 2013 · Therapeutic Advances in Gastroenterology
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