Modeling Indicates Greater Benefit Without Greater Cost for Increased Colorectal Adenoma Detection Rate in Colonoscopy Screening


Key Points

  • Higher adenoma detection rate was associated with reduced colorectal cancer incidence and mortality.
  • Higher adenoma detection rate was not associated with increased total costs for screening and treatment.

In a study reported in JAMA by Meester et al, microsimulation modeling of data from a U.S. community-based health-care system showed that colorectal cancer incidence and mortality were reduced with increased adenoma detection rate in colonoscopy screening, with no increase in total costs.

Study Details

The study involved data from 57,588 patients examined by 136 physicians from 1998 to 2010 in the Kaiser Permanente Northern California system. Using modeling, no screening was compared with screening initiation according to adenoma detection rate quintiles (averages) of 1 = 15.3%, 2 = 21.3%, 3 = 25.6%, 4 = 30.9%, and 5 = 38.7%; modeling included appropriate surveillance of patients with adenoma.

Incidence and Mortality

According to the simulation modeling, the lifetime risk of colorectal cancer was 34.2 per 1,000 patients and risk of mortality was 13.4/1,000 among nonscreened patients. Among screened patients, simulated lifetime incidence decreased from 26.6/1,000 for quintile 1 to 12.5/1,000 for quintile 5 and mortality decreased from 5.7/1000 to 2.3/1000. The differences represented an 11.4% reduction in incidence and 12.8% reduction in mortality for every 5% increase in adenoma detection rate.


The estimated number of colonoscopies increased from 2,777 to 3,376/1,000 from quintile 1 to quintile 5 (4.6% increase per 5% increase in detection rate), representing more frequent surveillance in higher quintiles. The estimated rate of serious complications (eg, postpolypectomy bleeding and perforation) increased from 2.2 to 3.2/1,000 and the estimated rate of overall complications increased from 6.0 to 8.9/1,000 (9.8% increase per 5% increase in detection rate). The rate of fatal complications increased from 0.03 to 0.05/1,000.


Estimated total screening ($2.8 million) and treatment ($2.4 million) costs were $5.2 million/1,000 patients in quintile 1 and $4.9 million/1,000 ($3.7 million for screening and $1.2 million for treatment) in quintile 5. Estimated net screening costs (derived by comparing estimated total screening and treatment costs for screening vs no screening) were $2.1 million/1,000 in quintile 1 and $1.8 million/1,000 in quintile 5 (3.2% reduction per 5% increase in detection rate).

The investigators concluded: “In this microsimulation modeling study, higher adenoma detection rates in screening colonoscopy were associated with lower lifetime risks of colorectal cancer and colorectal cancer mortality without being associated with higher overall costs. Future research is needed to assess whether increasing adenoma detection would be associated with improved patient outcomes.”

Reinier G. S. Meester, MSc, of Erasmus MC University Medical Center, is the corresponding author for the JAMA article.

The study was supported by National Cancer Institute grants.

The content in this post has not been reviewed by the American Society of Clinical Oncology, Inc. (ASCO®) and does not necessarily reflect the ideas and opinions of ASCO®.