Low adenoma detection rates (ADRs) were associated with a greater risk of death in colorectal cancer (CRC) patients, especially among those with high-risk adenomas, based on a review of more than 250,000 colonoscopies.
"Both performance quality of the endoscopist as well as specific characteristics of resected adenomas at colonoscopy are associated with colorectal cancer mortality," but the impact of these combined factors on colorectal cancer mortality has not been examined on a large scale, according to Elisabeth A. Waldmann, MD, of the Medical University of Vienna and colleagues.
In a study published in Clinical Gastroenterology & Hepatology, the researchers reviewed 259,885 colonoscopies performed by 361 endoscopists. Over an average follow-up period of 59 months, 165 CRC-related deaths occurred.
Across all risk groups, CRC mortality was higher among patients whose colonoscopies yielded an ADR of less than 25%, although this was not statistically significant in all groups.
The researchers then stratified patients into those with a negative colonoscopy, those with low-risk adenomas (one to two adenomas less than 10 mm), and those with high-risk adenomas (advanced adenomas or at least three adenomas), with the negative colonoscopy group used as the reference group for comparisons. The average age of the patients was 61 years, and approximately half were women.
Endoscopists were classified as having an ADR of less than 25% or 25% and higher.
Among individuals with low-risk adenomas, CRC mortality was similar whether the ADR on a negative colonoscopy was less than 25% or 25% or higher (adjusted hazard ratios, 1.25 and 1.22, respectively). CRC mortality also remained unaffected by ADR in patients with negatively colonoscopies (aHR, 1.27).
By contrast, individuals with high-risk adenomas had a significantly increased risk of CRC death if their colonoscopy was performed by an endoscopist with an ADR of less than 25%, compared with those whose endoscopists had ADRs of 25% or higher (aHR, 2.25 and 1.35, respectively).
"Our study demonstrated that adding ADR to the risk stratification model improved risk assessment in all risk groups," the researchers noted. "Importantly, stratification improved most for individuals with high-risk adenomas, the group demanding most resources in health care systems."
The study findings were limited by several factors including the focus on only screening and surveillance colonoscopies, not including diagnostic colonoscopies, and the inability to adjust for comorbidities and lifestyle factors that might impact CRC mortality, the researchers noted. The 22.4% average ADR in the current study was low, compared with other studies, and could be a limitation as well, although previous guidelines recommend a target ADR of at least 20%.
"Despite the extensive body of literature supporting the importance of ADR in terms of CRC prevention, its implementation into clinical surveillance is challenging," as physicians under pressure might try to game their ADRs, the researchers wrote.
The findings support the value of mandatory assessment of performance quality, the researchers added. However, "because of the potential possibility of gaming one's ADR one conclusion drawn by the study results should be that endoscopists' quality parameters should be monitored and those not meeting the standards trained to improve rather than requiring minimum ADRs as premise for offering screening colonoscopy."
Improve Performance, but Don't Discount Patient Factors
The study is important at this time because colorectal cancer is the third-leading cause of cancer death in the United States, Atsushi Sakuraba, MD, of the University of Chicago said in an interview.
"Screening colonoscopy has been shown to decrease CRC mortality, but factors influencing outcomes after screening colonoscopies remain to be determined," he said.
"It was expected that high-quality colonoscopy performed by an endoscopist with ADR of 25% or greater was associated with a lower risk for CRC death," Sakuraba said. "The strength of the study is that the authors demonstrated that high-quality colonoscopy was more important in individuals with high-risk adenomas, such as advanced adenomas or at least three adenomas."
The study findings have implications for practice in that they show the importance of monitoring performance quality in screening colonoscopy, Sakuraba said, "especially when patients have high-risk adenomas." However, "the authors included only age and sex as variables, but the influence of other factors, such as smoking, [body mass index], and race, need to be studied."
The researchers had no financial conflicts to disclose. Sakuraba had no financial conflicts to disclose.
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This article originally appeared on GI & Hepatology News, the official newspaper of the AGA Institute.
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Cite this: CRC Mortality Risk Correlates With Adenoma Detection Rate - Medscape - Jun 24, 2021.