Introduction

At present, for the average risk population, colonoscopy surveillance intervals are based on previous detected and resected polyps in an individual. Although an inverse association between the endoscopist’s adenoma detection rate (ADR) and the risk of developing post colonoscopy colorectal cancer (PCCRC) is widely recognized, performance measures of endoscopists are not taken into account when deciding on surveillance intervals. This study aims to evaluate how the individual endoscopist’s ADR compares to the presence of high-risk polyps when evaluating the risk of PCCRC in the 3 years following a complete screening colonoscopy.

Aims & Methods

Data of all complete colonoscopies in which no CRC was found, performed within the Dutch fecal immunochemical test (FIT) based CRC population screening program between 2014 and 2020, were used for this study. Data were linked to the Dutch cancer registry. Individuals were categorized into having high-risk polyps or no/low risk polyps based on the 2020 ESGE post-polypectomy colonoscopy surveillance guideline. ADR was calculated per endoscopist. Risk of PCCRC, defined as any CRC diagnosed 6 months after the index colonoscopy, within 3 years was evaluated with shared frailty cox proportional hazard regression analysis in which ADR and presence of high-risk polyps were utilized as independent variables. Secondary, endoscopists were categorized into three equal groups based on ADR (low/medium/high) to enable stratified analysis.

Results

In total 239.217 individuals were included of which 74.289 (31.1%) had high-risk polyps at baseline and 202 had PCCRC in the subsequent 3 years. Median ADR of the 441 endoscopists involved was 66.3% (IQR 61.4-69.9). Cumulative incidence of PCCRC was 2.66 (95%CI 2.21-3.11, table 1) per 10.000 person-years of follow-up in individuals with no or low-risk polyps and 2.54 (95%CI 1.92-3.15) in individuals with high-risk polyps. Presence of high-risk polyps was not associated with risk of PCCRC (HR 1.00; 95%CI 0.75-1.35), while ADR was associated (HR 0.94 per point increase in ADR; 95%CI 0.92-0.96). The cumulative incidence of PCCRC was 3.68 (95%CI 2.74-4.62, table 1) per 10.000 person-years of follow-up for individuals with no or low-risk polyps that were treated by an endoscopist with low ADR, as compared to 1.69 (95%CI 0.89-2.50) for individuals with high-risk polyps treated by an endoscopist with high ADR (HR 2.11; 95%CI 1.21-3.65). Individuals with high-risk polyps treated by an endoscopist with low ADR had the highest risk of PCCRC, while individuals with no or low-risk polyps treated by an endoscopist with high ADR had the lowest risk (HR 3.30; 95%CI 1.79-6.10).

Table 1: Cumulative incidence and stratified risk of ADR/presence of high-risk polyps on post colonoscopy colorectal cancer

Conclusion

We demonstrated that in the Dutch FIT-based CRC population screening program, the ADR of the endoscopist has a major impact on relative risk of PCCRC within 3 years after a complete colonoscopy, while the presence of high-risk polyps does not. This underscores the significant impact of quality of colonoscopy on the short-term development of PCCRC and undermines the current surveillance guidelines that rely solely on polyp features.

Introduction

Gastroduodenal neuroendocrine neoplasms (GD-NENs) are being increasingly diagnosed, particularly at stages amenable to endoscopic resection (ER). We aimed to evaluate endoscopic, long-term clinical and oncological outcomes of patients with GD-NENs submitted to ER.

Aims & Methods

Multinational retrospective study (24 centres, 10 Western countries) that analysed all patients who underwent ER of GD-NENs (January 2014-December 2024). Demographic, clinicopathological and long-term oncological data were collected. Curativeness of resection was defined according to the European Neuroendocrine Tumor Society guidelines (2023). Residual disease was defined as histological evidence of neoplastic tissue in the ER scar (local recurrence) or in surgical specimen (parietal residual lesion) and/or as the detection of lymph node metastasis either in the surgical specimen or in the follow-up (distant recurrence).

Results

We evaluated 445 patients: 304 gastric (G-NENs) (74.7% type 1, 19.1% type 3, 5.9% type 2) and 141 duodenal (D-NENs). The median lesion size was 10 mm (IQR 6-12). Endoscopic submucosal dissection (ESD) (32.6%) and conventional endoscopic mucosal resection (C-EMR) (26.5%) were the most performed techniques. G-NENs had significantly higher R0 rates (59.8%; 42.6% D-NENs; p<0.001). Non-curative ER rate was 56.4% (50.3% G-NENs; 69.5% D-NENs; p<0.001).
Median follow-up was 37 months (IQR 14-70). 28 patients (6.3%) needed surgery during follow up (6.3%), with similar rates between G-NENs and D-NENs. Parietal residual lesion was identified in 60.7% of surgical specimens (63.2% G-NENs, 55.6% D-NENs, p = 0.700). Residual disease rate was 16.2% (18.4% vs 11.6%, p = 0.059). Local and distant recurrence rate were 13.2% (14.8% G-NENs; 9.9% D-NENs; p=0.109) and 1.8% (1.3% G-NENs; 2.8% D-NENs; p=0.266), respectively. For type 1 / type 2 G-NENs, a non-curative ER implied significantly higher rates of residual disease (26.8% vs 9.7%, p = 0.005), local recurrence (25.0% vs 9.7%, p = 0.005) and distant recurrence rates (7.1% vs 0.0%, p = 0.014). Type 3 G-NENs also demonstrate higher residual disease rates in the non-curative ER group (26.8% vs 11.8%, p = 0.210). Considering D-NENs, non-curative ER was associated with a non-significant increase in residual disease rate (13.3% vs 7.0%, p = 0.278). There was a single case of NEN related mortality in a D-NEN patient.

Conclusion

In conclusion, our study demonstrates that despite non curative ERs in a significant proportion of patients, the recurrence and tumour-related mortality of GD-NENs remain low. Additionally, up to 40% of the patients submitted to surgery due to non-curative ER had absence of NEN in surgical specimen. These results provide critical insights that may refine clinical decision-making and inform future guidelines for the management of GD-NENs.

References

1. Panzuto, Francesco et al. “European Neuroendocrine Tumor Society (ENETS) 2023 guidance paper for gastroduodenal neuroendocrine tumours (NETs) G1-G3.” Journal of neuroendocrinology vol. 35,8 (2023): e13306. doi:10.1111/jne.13306