Using Online Colorectal Cancer Risk Calculators to Guide Screening Decision-making

  • Jennifer K. Maratt
    Address correspondence to: Jennifer K. Maratt, 1101 West Tenth Street, Indianapolis, IN 46202
    Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana

    Richard L. Roudebush VA Medical Center, Indianapolis, Indiana

    Regenstrief Institute, Inc. Indianapolis, Indiana
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  • Thomas F. Imperiale
    Division of Gastroenterology and Hepatology, Department of Medicine, Indiana University School of Medicine, Indianapolis, Indiana

    Richard L. Roudebush VA Medical Center, Indianapolis, Indiana

    Regenstrief Institute, Inc. Indianapolis, Indiana
    Search for articles by this author
Published:September 01, 2022DOI:



      Several online calculators estimate colorectal cancer risk, but their consistency is unknown. Our objectives were to quantify the variation in predicted risk and to determine which calculators are best used in the clinical setting.


      We used the Google search engine to identify online colorectal cancer risk calculators and assessed each's output for 3 hypothetical screening scenarios (low-, average-, and high-risk), varied by age (50, 62, 75 years), sex, and race (Black, White), with risk levels based on risk-appropriate values for variables in each model. Estimated risks for models within a given scenario were rated as consistent or inconsistent based on comparison to either the absolute magnitude of difference or average lifetime risk of colorectal cancer. Summary statistics for consistent and inconsistent estimates were compared using Chi-square and Fisher's exact tests.


      We identified 5 online colorectal cancer risk calculators. Inconsistencies were found in none of 5-year, 19% of 10-year, and 81% of lifetime colorectal cancer risk estimate comparisons (p<0.001). For a 50-year-old, 22% of risk estimate comparisons were inconsistent versus 33% for a 62-year-old, and 36% for a 75-year-old (p=0.14).


      Online colorectal cancer risk models are more consistent in predicting colorectal cancer risk for 5- and 10-year time frames compared to lifetime. For a U.S. population, the National Cancer Institute's Colorectal Cancer Risk Assessment Tool is a rigorously developed calculator that can be used in the clinical setting to provide 5-year and lifetime risk estimates.

      Clinical Significance

      • Currently available colorectal cancer risk calculators are more consistent in estimating risk for shorter time frames than for longer time frames. • The methodology with which a model was developed, population of interest, and desired time frame for risk estimates should be considered when deciding which risk calculator to use for screening decision-making. • The National Cancer Institute Colorectal Cancer Risk Assessment Tool provides the most accurate estimates for a U.S. patient population.


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        • American Cancer Society
        Colorectal Cancer Facts & Figures 2020.
        2020 (Available at) (Accessed September 10)
        • Robertson DJ
        • Ladabaum U.
        Opportunities and Challenges in Moving From Current Guidelines to Personalized Colorectal Cancer Screening.
        Gastroenterology. 2019; 156: 904-917
        • U.S. Preventive Services Task Force
        Screening for Colorectal Cancer: US Preventive Services Task Force Recommendation Statement.
        JAMA. 2016; 315: 2564-2575
        • U.S. Census Bureau
        National Population By Characteristics 2010-2019.
        2020 (Available at) (Accessed November 11)
        • Usher-Smith JA
        • Walter FM
        • Emery JD
        • Win AK
        • Griffin SJ.
        Risk prediction models for colorectal cancer: A systematic review.
        Cancer Prev Res. 2016; 9: 13-26
        • Ma GK
        • Ladabaum U.
        Personalizing Colorectal Cancer Screening: A Systematic Review of Models to Predict Risk of Colorectal Neoplasia.
        Clin Gastroenterol Hepatol. 2014; 12 (.e1): 1624-1634
        • Helsingen LM
        • Vandvik PO
        • Jodal HC
        • Agoritsas T
        • Lytvyn L
        • Anderson JC
        • et al.
        Colorectal cancer screening with faecal immunochemical testing, sigmoidoscopy or colonoscopy: A clinical practice guideline.
        BMJ. 2019; 367: 15515
        • Lieberman D
        • Ladabaum U
        • Cruz-Correa M
        • Ginsburg C
        • Inadomi JM
        • Kim LS
        • et al.
        Screening for colorectal cancer and evolving issues for physicians and patients: A review.
        JAMA. 2016; 316: 2135-2145
        • Usher-Smith JA
        • Harshfield A
        • Saunders CL
        • Sharp SJ
        • Emery J
        • Walter FM
        • et al.
        External validation of risk prediction models for incident colorectal cancer using UK Biobank.
        Br J Cancer. 2018; 118: 750-759
        • Park Y
        • Freedman AN
        • Gail MH
        • Pee D
        • Hollenbeck A
        • Schatzkin A
        • et al.
        Validation of a colorectal cancer risk prediction model among white patients age 50 years and older.
        J Clin Oncol. 2009; 27: 694-698
        • Hippisley-Cox J
        • Coupland C.
        Development and validation of risk prediction algorithms to estimate future risk of common cancers in men and women: Prospective cohort study.
        BMJ Open. 2015; 5e007825
        • Imperiale TF
        • Menggang Y
        • Monahan PO
        • Stump TE
        • Tabbey R
        • Glowinski E
        • et al.
        Risk of advanced neoplasia using the national cancer institute's colorectal cancer risk assessment tool.
        J Natl Cancer Inst. 2017; 109: 1-8
        • Ladabaum U
        • Patel A
        • Mannalithara A
        • Sundaram V
        • Mitani A
        • Desai M.
        Predicting Advanced Neoplasia at Colonoscopy in a Diverse Population with the National Cancer Institute Colorectal Cancer Risk-Assessment Tool.
        Cancer. 2016; 122: 2663-2670
        • Han PKJ
        • Duarte CW
        • Daggett S
        • Siewers A
        • Killam B
        • Smith KA
        • et al.
        Effects of personalized colorectal cancer risk information on laypersons’ interest in colorectal cancer screening: The importance of individual differences.
        Patient Educ Couns. 2015; 98: 1280-1286
        • Yen T
        • Qin F
        • Sundaram V
        • Asiimwe E
        • Storage T
        • Ladabaum U.
        Randomized Controlled Trial of Personalized Colorectal Cancer Risk Assessment vs Education to Promote Screening Uptake.
        Am J Gastroenterol. 2021; 116: 391-400
        • Kolonel LN
        • Henderson BE
        • Hankin JH
        • Nomura AMY
        • Wilkens LR
        • Pike MC
        • et al.
        A Multiethnic Cohort in Hawaii and Los Angeles: Baseline Characteristics.
        Am J Epidemiol. 2000; 151: 346-357