Colorectal Cancer Screening 2021

Patient Guideline Summary

Publication Date: February 28, 2021
Last Updated: March 3, 2023

Objective

Objective

This patient summary means to update and summarize key recommendations from the American College of Gastroenterology (ACG) for colorectal cancer screening. This patient summary is limited to adults 18 years of age and older and should not be used as a reference for children.

Overview

Overview

  • In the United States, colorectal cancer is the second cause of cancer death after lung cancer. Also, it is the third most common cancer in both men and women.
  • We will use the abbreviation CRC throughout this summary to refer to colorectal cancer.
  • About 70% of sporadic CRCs originate from lesions called adenomas. 25%–30% arise from lesions called sessile serrated lesions (SSLs). So, CRC screening aims to detect early-stage CRC and remove adenomas and SSLs.
  • This patient summary focuses on updating the 2009 American College of Gastroenterology (ACG) CRC screening guideline.

Screening

Screening

  • For CRC screening, there are several approved tests, each with its strengths and weaknesses. The “best” screening test is the one that is acceptable to the patient and gets completed.
  • CRC screening tests are either one-step or two-step procedures:
    • Colonoscopy (where the doctor inserts a long, thin instrument with a camera at the end to look inside your colon) is a one-step test – both diagnostic and therapeutic)
      • Colonoscopy allows for the detection of early-stage cancers and also the detection and removal of polyps.
    • Two-step tests, if positive, require colonoscopy to complete the screening process.
      • All screening tests other than colonoscopy are two-step tests.
  • ACG recommends CRC screening in average-risk individuals between ages 50 and 75 years to reduce the incidence of advanced adenoma, CRC, and death from CRC.
  • ACG suggests CRC screening in average-risk individuals between ages 45 and 49 years to reduce the incidence of advanced adenoma, CRC, and mortality from CRC.
  • ACG suggests that a decision to continue screening beyond the age of 75 years be individualized.
  • ACG recommends colonoscopy and fecal immunochemical test (FIT) (a special test on a stool sample) as the primary screening methods for CRC screening.
  • ACG suggests consideration of the following screening tests if you are unable or unwilling to undergo colonoscopy or FIT:
    • flexible sigmoidoscopy (which allows direct evaluation of the left side of the colon and if adenomas are found, colonoscopy is needed)
    • multitarget stool DNA test
    • CT colonography (CTC) (a type of CT uses low radiation to view the colon) or
    • colon capsule (CC) (a tiny camera to swallow).
  • ACG does not recommends Septin 9 for CRC screening.
  • ACG recommends the following intervals for screening tests:
    • FIT every 1 year
    • Colonoscopy every 10 years
  • ACG suggests the following intervals for other screening tests:
    • Multi-target stool DNA test every 3 years
    • Flexible sigmoidoscopy every 5–10 years
    • CTC every 5 years
    • CC every 5 years
  • ACG suggests starting CRC screening with a colonoscopy at age 40 or 10 years before the youngest affected relative, whichever is earlier, for individuals with:
    • CRC or advanced polyp in one first degree relative (FDR) (this includes a person's parent [father or mother], full sibling [brother or sister] or child) at age <60 years or
    • CRC or advanced polyp in ≥2 FDR at any age.
      • ACG suggests interval colonoscopy every 5 years.
  • ACG suggests consideration of genetic testing with higher familial CRC burden (higher number and/or younger age of affected relatives).
  • ACG suggests starting CRC screening at age 40 or 10 years before the youngest affected relative and then continuing average-risk screening recommendations for individuals with:
    • CRC or
    • an advanced polyp in one FDR at age under 60 years or
    • CRC or advanced polyp in more than two FDRs at any age.
  • If you have one second-degree relative (SDR) with CRC or advanced polyp, ACG suggests following average-risk CRC screening recommendations.
  • All doctors who perform colonoscopy must be trained and prove their ability to do it safely and effectively. In addition, ACG recommends that results of testing and treatment be pooled and examined for ways to improve the process and reduce the rate of CRC.
  • Aspirin reduces the risk of CRC. Your doctor may prescribe low-dose aspirin if you are between the ages of 50–69 years with a cardiovascular disease risk of ≥10% over the next 10 years, not an increased risk for bleeding and willing to take aspirin daily for at least 10 years.
  • ACG does not recommend the use of aspirin as a substitute for CRC screening.
  • If you have a positive screening test, you may receive mail and phone messages as follow-up reminders.

Abbreviations

  • CC: Colon Capsule
  • CRC: Colorectal Cancer
  • CTC: CT Colonography
  • FDR: First Degree Relative
  • FIT: Fecal Immunochemical Test
  • SDR: Second-degree Relative
  • SSLs: Sessile Serrated Lesions

Source Citation

Shaukat A, Kahi CJ, Burke CA, Rabeneck L, Sauer BG, Rex DK. ACG Clinical Guidelines: Colorectal Cancer Screening 2021. Am J Gastroenterol. 2021 Mar 1;116(3):458-479. doi: 10.14309/ajg.0000000000001122. PMID: 33657038.

Disclaimer

The information in this patient summary should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.