Spectrum of Advanced Colorectal Neoplasia and Anticipated Yield of Average-Risk Screening in Veterans Under Age 50

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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Prevalence of advanced colorectal neoplasia according to risk categories at screening colonoscopy in a tertiary referral center.

Journal of Clinical Oncology ◽

10.1200/jco.2018.36.4_suppl.578 ◽

2018 ◽

Vol 36 (4_suppl) ◽

pp. 578-578

Author(s):

Eduardo Negrete Carballo ◽

Fidel David Huitzil Melendez

Keyword(s):

Colorectal Cancer ◽

High Risk ◽

Risk Stratification ◽

Colorectal Neoplasia ◽

Screening Colonoscopy ◽

Average Risk ◽

Moderate Risk ◽

Advanced Colorectal Neoplasia ◽

Advanced Neoplasm ◽

Colorectal Screening

578 Background: Colorectal cancer (CRC) is the third most common cancer in the world. There is strong evidence that screening for colorectal cancer improves survival in conutries with high incidence. Although Mexico is considered a country with a low incidence of CRC, 4694 potentially preventable deaths occur every year. There is no established CRC screening program in our country, risk stratification of the target populations to be screened may bring potential advantages, making the strategy more cost-effective. The Asia-Pacific Colorectal Screening (APCS) score, is a validated risk-stratification tool that helps identify individuals at risk for advanced colorectal neoplasm amongst the asymptomatic population. Methods: We performed a retrospective, cross-sectional analysis of database records from 1172 patients who underwent screening colonoscopy betwen january 2013 and november 2014. Results: The prevalence of advanced colorectal neoplasia was 2.9%. Applying the APCS stratification, 91 subjects (7.8%) were in the average risk tier, 849 subjects (72.4%) in the moderate risk tier and 232 (19.8%) subjects in the high risk tier. The prevalence of advanced neoplasia in the average risk, moderate risk and high risk groups was 0%, 2.6% and 5.1%, respectively. The subjects in the high risk tier had 2.21-fold (p = 0.021) increased prevalence of advanced neoplasia than those in the average-moderate tier. Conclusions: The APCS score is a simple risk stratification index for colorectal advanced neoplasm that uses elementary clinical information on age, gender, family history and smoking to stratify the risk of colorectal advanced neoplasm in asymptomatic subjects for priority of colorectal screening.

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