A new 5-variable risk index for advanced neoplasia may aid in decision making about colorectal cancer screening and deciding optimally among screening options, according to a study of 4,460 persons aged 50 to 80 years and whose prevalence of advanced neoplasia was 9.4%. The index stratifies risk for advanced neoplasia in a general population by identifying lower-risk groups for which noncolonoscopy strategies may be efficient and a higher-risk group for which colonoscopy may be preferred. Results of the study showed:

• Among 2,993 persons in the derivation set, risks for advanced neoplasia in persons at very low, low, intermediate, and high risk were 1.92%, 4.88%, 9.93%, and 24.9%, respectively, and sigmoidoscopy to the descending colon in the low-risk group would have detected 73% of advanced neoplasms.

• Among 1,467 persons in the validation set, corresponding risk for advanced neoplasia were 1.65%, 3.31%, 10.9%, and 22.3%, respectively, and sigmoidoscopy would have detected 87.5% advanced neoplasms.

Citation: Imperiale TF, Monahan PO, Stump TE, Glowinski EA, Ransohoff DF. Derivation and validation of a scoring system to stratify risk for advanced colorectal neoplasia in asymptomatic adults. Ann Intern Med. [Published online ahead of print August 11, 2015]. doi: 10.7326/M14-1720.

Commentary: The USPSTF recommends screening for colorectal cancer using fecal occult blood testing, sigmoidoscopy, or colonoscopy in adults, beginning at aged 50 years and continuing until age 75 years. Neither the USPSTF or the American Cancer Society recommendations distinguish choices based on colorectal cancer risk, which is an issue given the invasive nature of colonoscopy, the most commonly recommended colorectal cancer screening method. The risks of colonoscopy are real, with a reported risk of perforation of approximately 1 in 2,000, and an increase in 30-day post-procedure cardiovascular risk of approximately 1 in 2,000 as well as risks of hemorrhage and postpolypectomy electrocoagulation syndrome of 1 in 10,000. The recommended screening algorithm, which uses age, sex, family history of a first degree relative with colorectal cancer, waist circumference, and smoking status, provides an interesting alternative to the usual one-size-fits-all approach. —Neil Skolnik, MD

1. American Cancer Society website. Colorectal cancer screening guidelines. http://www.cancer.org/cancer/colonandrectumcancer/moreinformation/colonandrectumcancerearlydetection/colorectal-cancer-early-detection-acs-recommendations. Updated February 5, 2015. Accessed August 8, 2015.

2. Fisher D. Complications of colonoscopy. Gastrointestinal Endoscopy 2011; 74:745-752.