Long-term Risk of Colorectal Cancer and Related Death After Adenoma Removal in a Large, Community-based Population

Gastroenterology. 2020 Mar;158(4):884-894.e5. doi: 10.1053/j.gastro.2019.09.039. Epub 2019 Oct 4.

Abstract

Background & aims: The long-term risks of colorectal cancer (CRC) and CRC-related death following adenoma removal are uncertain. Data are needed to inform evidence-based surveillance guidelines, which vary in follow-up recommendations for some polyp types. Using data from a large, community-based integrated health care setting, we examined the risks of CRC and related death by baseline colonoscopy adenoma findings.

Methods: Participants at 21 medical centers underwent baseline colonoscopies from 2004 through 2010; findings were categorized as no-adenoma, low-risk adenoma, or high-risk adenoma. Participants were followed until the earliest of CRC diagnosis, death, health plan disenrollment, or December 31, 2017. Risks of CRC and related deaths among the high- and low-risk adenoma groups were compared with the no-adenoma group using Cox regression adjusting for confounders.

Results: Among 186,046 patients, 64,422 met eligibility criteria (54.3% female; mean age, 61.6 ± 7.1 years; median follow-up time, 8.1 years from the baseline colonoscopy). Compared with the no-adenoma group (45,881 patients), the high-risk adenoma group (7563 patients) had a higher risk of CRC (hazard ratio [HR] 2.61; 95% confidence interval [CI] 1.87-3.63) and related death (HR 3.94; 95% CI 1.90-6.56), whereas the low-risk adenoma group (10,978 patients) did not have a significant increase in risk of CRC (HR 1.29; 95% CI 0.89-1.88) or related death (HR 0.65; 95% CI 0.19-2.18).

Conclusions: With up to 14 years of follow-up, high-risk adenomas were associated with an increased risk of CRC and related death, supporting early colonoscopy surveillance. Low-risk adenomas were not associated with a significantly increased risk of CRC or related deaths. These results can inform current surveillance guidelines for high- and low-risk adenomas.

Keywords: Adenoma; Colonoscopy; Colorectal Cancer; Polyp.

Publication types

  • Multicenter Study
  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adenoma / pathology
  • Adenoma / surgery*
  • Aged
  • California / epidemiology
  • Colonoscopy / standards*
  • Colonoscopy / statistics & numerical data
  • Colorectal Neoplasms / diagnostic imaging
  • Colorectal Neoplasms / epidemiology*
  • Colorectal Neoplasms / pathology
  • Colorectal Neoplasms / prevention & control
  • Early Detection of Cancer / standards*
  • Early Detection of Cancer / statistics & numerical data
  • Evidence-Based Medicine / standards*
  • Evidence-Based Medicine / statistics & numerical data
  • Female
  • Follow-Up Studies
  • Humans
  • Male
  • Medical History Taking
  • Middle Aged
  • Practice Guidelines as Topic
  • Proportional Hazards Models
  • Retrospective Studies
  • Risk Assessment
  • Risk Factors
  • Time Factors