Endoscopist skill found to predict short-term post-colonoscopy cancer
In the short term, the quality of the endoscopist is a stronger driver of cancer risk than polyp characteristics.
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10/24/2025
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by Julian Upton
A large population-based study using data from the Dutch Fecal Immunochemical Test-based colorectal cancer (CRC) screening program has shown that short-term risk of post-colonoscopy colorectal cancer depends more on endoscopic performance than on the presence of high-risk polyps.
Researchers followed more than 239,000 individuals between 2014 and 2020 after a positive fecal immunochemical test. Investigators compared whether cancers appearing within three years were linked more closely to polyp features or to the quality indicators of the endoscopist, noted Nanette S. van Roermund (Amsterdam University Medical Center), and colleagues.
High-risk polyps—defined as adenomas 10 mm or larger, those with high-grade dysplasia, or multiple adenomas—are usually considered the main reason for shortened surveillance intervals. Yet the study found no association between the presence of these polyps and the development of post-colonoscopy colorectal cancer within 3 years, according to results published in Clinical Gastroenterology and Hepatology.
By contrast, endoscopist performance, as measured by adenoma detection rate (ADR) and proximal serrated polyp detection rate (PSPDR), showed strong inverse associations with risk. Each one-point increase in ADR was linked to a 6% reduction in post-colonoscopy cancer risk, and each one-point increase in PSPDR corresponded to an 8% reduction.
The analysis revealed contrasts. Individuals with no or low-risk polyps examined by an endoscopist with a high ADR had the lowest incidence of post-colonoscopy colorectal cancer, whereas those with high-risk polyps examined by endoscopists with low ADRs had the highest incidence. “The risk to develop post-colonoscopy colorectal cancer was at least two times higher in individuals with no or low-risk polyps examined by an endoscopist with low ADR or PSPDR compared with individuals with high-risk polyps but examined by an endoscopist with a high ADR or PSPDR,” wrote the investigators.
Similar patterns were observed when stratified by PSPDR. The findings suggest that, in the short term, the quality of the endoscopist is a stronger driver of cancer risk than polyp characteristics. This observation challenges the way current surveillance intervals are determined, since guidelines today are based largely on polyp features without consideration of the performance of the endoscopist.
Roermund and fellow researchers noted that incorporating ADR and PSPDR into risk stratification, or embedding them more firmly into quality assurance programs, could reduce the number of missed cancers. They also suggested that existing benchmarks may be set too low, noting that even though Dutch guidelines require an ADR of at least 40%, endoscopists in the lowest-performing category of this study had ADRs well above that threshold, yet still exhibited higher rates of missed cancers.
The study had some limitations. It focused on cancers occurring within three years of colonoscopy, a period when endoscopist quality appears to be most relevant, but longer-term risk may be more strongly influenced by polyp biology. The high baseline ADRs and PSPDRs in the Dutch program may also limit generalizability to settings with lower detection rates. In addition, by design, the study excluded individuals referred for more advanced endoscopic resection techniques, which may have influenced the risk profile of the high-risk polyp group.
“Nevertheless, [the study’s] timeframe also presents a major strength,” the authors added. “Previous long-term studies evaluating endoscopist performance in relation to polyp features are biased by the potential for increased surveillance in individuals with high-risk polyp, making their results challenging to interpret.”
Strengthening national quality assurance programs, raising minimum benchmarks, and providing training to improve detection rates, the authors write, could all help reduce the burden of post-colonoscopy colorectal cancer.
Author disclosures can be found in the published research article.
Summary content
7 Key Takeaways
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Developed a paper-based colorimetric sensor array for chemical threat detection.
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Can detect 12 chemical agents, including industrial toxins.
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Production cost is under 20 cents per chip.
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Utilizes dye-loaded silica particles on self-adhesive paper.
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Provides rapid, simultaneous identification through image analysis.
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Inspired by the mammalian olfactory system for pattern recognition.
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Future developments include a machine learning-enabled reader device.
The guidelines emphasize four-hour gastric emptying studies over two-hour testing. How do you see this affecting diagnostic workflows in practice?
Dr. Staller: Moving to a four-hour solid-meal scintigraphy will actually simplify decision-making. The two-hour reads miss a meaningful proportion of delayed emptying; standardizing on four hours reduces false negatives and the “maybe gastroparesis” purgatory that leads to repeat testing. Practically, it means closer coordination with nuclear medicine (longer slots, consistent standardized meal), updating order sets to default to a four-hour protocol, and educating front-line teams so patients arrive appropriately prepped. The payoff is fewer equivocal studies and more confident treatment plans.
Metoclopramide and erythromycin are the only agents conditionally recommended for initial therapy. How does this align with what is being currently prescribed?
Dr. Staller: This largely mirrors real-world practice. Metoclopramide remains the only FDA-approved prokinetic for gastroparesis, and short “pulsed” erythromycin courses are familiar to many of us—recognizing tachyphylaxis limits durability. Our recommendation is “conditional” because the underlying evidence is modest and patient responses are heterogeneous, but it formalizes what many clinicians already do: start with metoclopramide (lowest effective dose, limited duration, counsel on neurologic adverse effects) and reserve erythromycin for targeted use (exacerbations, bridging).
Several agents, including domperidone and prucalopride, received recommendations against first-line use. How will that influence discussions with patients who ask about these therapies?
Dr. Staller: Two points I share with patients: evidence and access/safety. For domperidone, the data quality is mixed, and US access is through an FDA IND mechanism; you’re committing patients to EKG monitoring and a non-trivial administrative lift. For prucalopride, the gastroparesis-specific evidence isn’t strong enough yet to justify first-line use. So, our stance is not “never,” it’s just “not first.” If someone fails or cannot tolerate initial therapy, we can revisit these options through shared decision-making, setting expectations about benefit, monitoring, and off-label use. The guideline language helps clinicians have a transparent, evidence-based conversation at the first visit.
The guidelines suggest reserving procedures like G-POEM and gastric electrical stimulation for refractory cases. In your practice, how do you decide when a patient is “refractory” to medical therapy?
Dr. Staller: I define “refractory” with three anchors.
1. Adequate trials of foundational care: dietary optimization and glycemic control; an antiemetic; and at least one prokinetic at appropriate dose/duration (with intolerance documented if stopped early).
2. Persistent, function-limiting symptoms: ongoing nausea/vomiting, weight loss, dehydration, ER visits/hospitalizations, or malnutrition despite the above—ideally tracked with a validated instrument (e.g., GCSI) plus nutritional metrics.
3. Objective correlation: delayed emptying on a standardized 4-hour solid-meal study that aligns with the clinical picture (and medications that slow emptying addressed).
At that point, referral to a center with procedural expertise for G-POEM or consideration of gastric electrical stimulation becomes appropriate, with multidisciplinary evaluation (GI, nutrition, psychology, and, when needed, surgery).
What role do you see dietary modification and glycemic control playing alongside pharmacologic therapy in light of these recommendations?
Dr. Staller: They’re the bedrock. A small-particle, lower-fat, calorie-dense diet—often leaning on nutrient-rich liquids—can meaningfully reduce symptom burden. Partnering with dietitians early pays dividends. For diabetes, tighter glycemic control can improve gastric emptying and symptoms; I explicitly review medications that can slow emptying (e.g., opioids; consider timing/necessity of GLP-1 receptor agonists) and encourage continuous glucose monitor-informed adjustments. Pharmacotherapy sits on top of those pillars; without them, medications will likely underperform.
The guideline notes “considerable unmet need” in gastroparesis treatment. Where do you think future therapies or research are most urgently needed?
Dr. Staller: I see three major areas.
1. Truly durable prokinetics: agents that improve emptying and symptoms over months, with better safety than legacy options (e.g., next-gen motilin/ghrelin agonists, better-studied 5-HT4 strategies).
2. Endotyping and biomarkers: we need to stop treating all gastroparesis as one disease. Clinical, physiologic, and microbiome/omic signatures that predict who benefits from which therapy (drug vs G-POEM vs GES) would transform care.
3. Patient-centered trials: larger, longer RCTs that prioritize validated symptom and quality-of-life outcomes, include nutritional endpoints, and reflect real-world medication confounders.
Our guideline intentionally highlights these gaps to hopefully catalyze better trials and smarter referral pathways.
Dr. Staller is with the Division of Gastroenterology, Massachusetts General Hospital and Harvard Medical School, Boston.