Derivation and Validation of a Scoring System to Stratify Risk for Advanced Colorectal Neoplasia in Asymptomatic Adults

Abstract

Background Several methods are recommended equally strongly for colorectal cancer screening in average-risk persons. Risk stratification would enable tailoring of screening within this group, with less invasive tests (sigmoidoscopy or occult blood tests) for lower-risk persons and colonoscopy for higher-risk persons. Objective To create a risk index for advanced neoplasia (colorectal cancer and adenomas or serrated polyps ≥1.0 cm, villous histology, or high-grade dysplasia) anywhere in the colorectum, using the most common risk factors for colorectal neoplasia. Design Cross-sectional study. Setting Multiple endoscopy units, primarily in the Midwest. Patients Persons aged 50 to 80 years undergoing initial screening colonoscopy (December 2004 to September 2011). Measurements Derivation and validation of a risk index based on points from regression coefficients for age, sex, waist circumference, cigarette smoking, and family history of colorectal cancer. Results Among 2993 persons in the derivation set, prevalence of advanced neoplasia was 9.4%. Risks for advanced neoplasia in persons at very low, low, intermediate, and high risk were 1.92% (95% CI, 0.63% to 4.43%), 4.88% (CI, 3.79% to 6.18%), 9.93% (CI, 8.09% to 12.0%), and 24.9% (CI, 21.1% to 29.1%), respectively (P < 0.001). Sigmoidoscopy to the descending colon in the low-risk groups would have detected 51 of 70 (73% [CI, 61% to 83%]) advanced neoplasms. Among 1467 persons in the validation set, corresponding risks for advanced neoplasia were 1.65% (CI, 0.20% to 5.84%), 3.31% (CI, 2.08% to 4.97%), 10.9% (CI, 8.26% to 14.1%), and 22.3% (CI, 16.9% to 28.5%), respectively (P < 0.001). Sigmoidoscopy would have detected 21 of 24 (87.5% [CI, 68% to 97%]) advanced neoplasms. Limitations Split-sample validation; results apply to first-time screening. Conclusion This index stratifies risk for advanced neoplasia among average-risk persons by identifying lower-risk groups for which noncolonoscopy strategies may be effective and efficient and a higher-risk group for which colonoscopy may be preferred.

NCI seeks to speed drug development for pediatric cancers: New initiative aims to help prioritize agents with most potential

“…A new test developed by researchers at the Regenstrief Institute and the Indiana University School of Medicine, both in Indianapolis, may help physicians determine which patients should receive screening with colonoscopy and who can skip the test. 1 Lead author Thomas Imperiale, MD, professor of medicine at the Indiana University School of Medicine, says he and his colleagues were primarily attempting to determine whether risk factors frequently associated with colorectal cancer and advanced precancerous polyps could be used in combination to stratify risk for advanced neoplasia in average-risk individuals.…”

CRC Screening: Is It Worthwhile in Younger Adults?

“…Of note, in the previous study, adults in the 30-39-year age group who smoked 20 or more pack-years had over a fourfold risk (adjusted odds ratio 4.41; 95 % CI 1.80-10.80; p \ 0.001) for advanced neoplasia as compared to those with a lower exposure. Smoking, at even higher exposure levels of 30 or more pack-years, has a twofold risk of adenomas in young and older adults [5,7,11]. Other similar studies have also documented that smoking is an important predictor in younger adults when using a definition of current smoking as an exposure variable [12,13].…”

“…The authors also include two important CRC risk factors, obesity and smoking, as part of their strategy, factors which have been highlighted by the 2009 ACG CRC screening guidelines as potentially important for the identification high-risk individuals [1]. Further, obesity [4] and smoking [5] have also been identified as important factors in large cross-sectional studies and advanced adenoma prediction models developed in older populations [6,7]. Finally, the authors combined lifestyle factors with biologic-based factors in the form of commonly ordered laboratory tests.…”

Challenges to the adoption of risk algorithms for colorectal cancer screening programmes: perspectives for future research

“…6 Other validated risk scores have been constructed using similar methods and have potential for use in clinical practice. 7,8 Yeoh et al 5 also identified some issues related to the application of the APCS score. The objective of this commentary is to discuss the potential challenges and perspectives for future research into risk-based CRC screening.…”