Screening colonoscopy in asymptomatic average-risk Koreans: Analysis in relation to age and sex

Abstract Background: Single nucleotide polymorphism (SNP)-based polygenic risk scoring is predictive of colorectal cancer (CRC) risk. However, few studies have investigated the association of genetic risk score (GRS) with detection of adenomatous polyps at screening colonoscopy. Methods: We randomly selected 1,769 Caucasian subjects who underwent screening colonoscopy from the Genomic Health Initiative (GHI), a biobank of NorthShore University HealthSystem. Outcomes from initial screening colonoscopy were recorded. Twenty-two CRC risk-associated SNPs were obtained from the Affymetrix™ SNP array and used to calculate an odds ratio (OR)-weighted and population-standardized GRS. Subjects with GRS of <0.5, 0.5-1.5, and >1.5 were categorized as low, average and elevated risk.Results: Among 1,769 subjects, 520 (29%) had 1 or more adenomatous polyps. GRS was significantly higher in subjects with adenomatous polyps than those without; mean (95% confidence interval) was 1.02 (1.00-1.05) and 0.97 (0.95-0.99), respectively, p<0.001. The association remained significant after adjusting for age, gender, body mass index, and family history, p<0.001. The detection rate of adenomatous polyps was 10.8%, 29.0% and 39.7% in subjects with low, average and elevated GRS, respectively, p-trend <0.001. Higher GRS was also associated with early age diagnosis of adenomatous polyps, p<0.001. In contrast, positive family history was not associated with risk and age of adenomatous polyps.Conclusions: GRS was significantly associated with adenomatous polyps in subjects undergoing screening colonoscopy. This result may help in stratifying average risk patients and facilitating personalized colonoscopy screening strategies.

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Surveying ADR knowledge and practices among US gastroenterologists

Proceedings of IMPRS ◽

10.18060/22743 ◽

2018 ◽

Vol 1 (1) ◽

Author(s):

Michael Peng ◽

Douglas Rex, MD, MACG

Keyword(s):

Bowel Preparation ◽

Detection Rate ◽

Online Survey ◽

Screening Colonoscopy ◽

Current Evidence ◽

Serrated Polyps ◽

The Past ◽

Adenoma Detection ◽

Age And Sex

Background: The adenoma detection rate (ADR) is of primary importance to the quality of screening colonoscopy. An online survey was conducted to assess knowledge and practices on ADR. Methods: Paid questionnaire distributed by email. Eligible respondents were board certified gastroenterologists who perform >80 colonoscopies per month with 3 to 35 years after fellowship. Results: 39% were unaware that ADR applies only to screening colonoscopies and 76% incorrectly answered that ADR includes sessile serrated polyps/adenomas. 51% of respondents incorrectly believe the threshold is set at 25% because 25% is a national ADR average. Many also believe the threshold depends on the patient population (current evidence suggests adjusting ADR for factors other than age and sex is unnecessary). 75% ranked ADR as highly important. 80% reported tracking ADR. A busy practice was the most common reason for not tracking ADR. Caps, chromoendoscopy, and good bowel preparation were viewed as valuable for improving ADR (this is true except for caps). HD colonoscopes and education were considered less valuable (although evidence suggests HD and education are associated with improved ADR). 57% reported not sharing ADR information with their patients, and 59% reported no patients in the past 6 months asking for their ADR. Conclusion: The importance of ADR as a validated quality measure is well understood, but there are misconceptions among gastroenterologists regarding the definition and measurement of ADR and which methods are proven to increase ADR. Patients are having very little impact on ADR measurement.

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Derivation and validation of a predictive model for advanced colorectal neoplasia in asymptomatic adults

Gut ◽

10.1136/gutjnl-2020-321698 ◽

2020 ◽

pp. gutjnl-2020-321698

Author(s):

Thomas F Imperiale ◽

Patrick O Monahan ◽

Timothy E Stump ◽

David F Ransohoff

Keyword(s):

High Risk ◽

Colorectal Neoplasia ◽

Risk Groups ◽

Low Risk ◽

Screening Tests ◽

Screening Colonoscopy ◽

Average Risk ◽

Intermediate Risk ◽

C Statistic ◽

Advanced Colorectal Neoplasia

ObjectiveKnowing risk for advanced colorectal neoplasia (AN) could help patients and providers choose among screening tests, improving screening efficiency and uptake. We created a risk prediction model for AN to help decide which test might be preferred, a use not considered for existing models.DesignAverage-risk 50-to-80-year olds undergoing first-time screening colonoscopy were recruited from endoscopy units in Indiana. We measured sociodemographic and physical features, medical and family history and lifestyle factors and linked these to the most advanced finding. We derived a risk equation on two-thirds of the sample and assigned points to each variable to create a risk score. Scores with comparable risks were collapsed into risk categories. The model and score were tested on the remaining sample.ResultsAmong 3025 subjects in the derivation set (mean age 57.3 (6.5) years; 52% women), AN prevalence was 9.4%. The 13-variable model (c-statistic=0.77) produced three risk groups with AN risks of 1.5% (95% CI 0.72% to 2.74%), 7.06% (CI 5.89% to 8.38%) and 27.26% (CI 23.47% to 31.30%) in low-risk, intermediate-risk and high-risk groups (p value <0.001), containing 23%, 59% and 18% of subjects, respectively. In the validation set of 1475 subjects (AN prevalence of 8.4%), model performance was comparable (c-statistic=0.78), with AN risks of 2.73% (CI 1.25% to 5.11%), 5.57% (CI 4.12% to 7.34%) and 25.79% (CI 20.51% to 31.66%) in low-risk, intermediate-risk and high-risk subgroups, respectively (p<0.001), containing proportions of 23%, 59% and 18%.ConclusionAmong average-risk persons, this model estimates AN risk with high discrimination, identifying a lower risk subgroup that may be screened non-invasively and a higher risk subgroup for which colonoscopy may be preferred. The model could help guide patient–provider discussions of screening options, may increase screening adherence and conserve colonoscopy resources.

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