Introduction

Existing data on long-term colorectal cancer (CRC) incidence after polyp removal has limitations. Colonoscopy surveillance is frequently performed post-polypectomy, altering CRC incidence, but this is often not adequately addressed in analyses. Additionally, numbers of CRC cases are often insufficient for precise estimates or subgroup analyses.

Aims & Methods

Our aim was to examine long-term CRC incidence, unperturbed by surveillance, in patients who had no polyps or low-risk polyps at endoscopic screening, by anatomic subsite. In the UK Flexible Sigmoidoscopy Screening Trial, ~41,000 participants had a once-only flexible sigmoidoscopy screen and were followed-up for a median of 21 years. This analysis includes participants who had no polyps or low-risk polyps found in the distal colon or rectum at screening, with polypectomy when needed. Only 0.5% had a baseline colonoscopy and 0.2% had colonoscopy surveillance. Participants with low-risk polyps were those with <3 adenomas <10mm with tubular histology and low-grade dysplasia and/or hyperplastic polyps <10mm. Outcomes were incident CRC by anatomic subsite (distal, proximal). Time-to-event data were censored at any first surveillance colonoscopy. Cox regression compared incidence between those with no polyps and those with low-risk polyps, adjusted for age, sex, and baseline characteristics independently associated with CRC incidence. Standardised incidence ratios compared incidence to that in the general population (England, 2005).

Results

Of 37,911 participants in the analysis, 29,810 (79%) had no polyps and 8,101 (21%) had low-risk polyps. Compared to those with no polyps, distal and proximal cancer incidence was higher in those with low-risk polyps. Compared to the general population, distal cancer incidence was lower in those with no polyps and in those with low-risk polyps. Compared to the general population, proximal cancer incidence was not significantly different in those with no polyps but was higher in those with low-risk polyps (Table 1).

Conclusion

After flexible sigmoidoscopy screening, with no colonoscopy surveillance, the risk of distal cancer among those with no polyps or low-risk polyps was substantially lower than in the general population; however, among those with low-risk polyps, the risk of proximal cancer was higher than in the general population. Participants with distal low-risk polyps at baseline appear to have had a propensity for synchronous and/or metachronous proximal neoplasia and might have benefited from a baseline or surveillance colonoscopy.

Introduction

The 6-minute withdrawal time for colonoscopy is widely considered the standard of care. However, there may not be appropriate if the 6-minute is equally divided into various colon segments. Since the adenoma detection in each colon segment is not the same, there may be differences with the withdrawal time in different colon segments.

Aims & Methods

Our objective was to evaluate the relationships between adenoma detection rate (ADR) and respective withdrawal time in different colon segments. Outpatients, age range 18-75 years, undertaking complete colonoscopy were enrolled in this study from November 2019 to November 2020 in the digestive endoscopy center. The entire colon was divided into four different segments: ascending colon, transverse colon, descending colon and rectosigmoid colon. The respective withdrawal time and ADR in each colon segment were recorded respectively.

Results

A total of 586 outpatients (279 males, 307 females) enrolled in this study and the general ADR was 38.2%. The positive withdrawal time (adenomas detected) was longer than negative withdrawal time (non-adenomas detected) (334.04±24.21 secs vs 303.65±5.20 secs, t=1.26, P<0.001). ADR in ascending colon, transverse colon, descending colon and rectosigmoid colon were respectively 30.5%, 2.9%, 3.1% and 7.5%. While all of their positive withdrawal time were longer than negative withdrawal time (94.34±33.76 secs vs 70.40±41.84 secs, t=3.31, P=0.001; 85.40±49.76 secs vs 71.66±36.87 secs, t=1.95, P=0.025; 80.29±39.85 secs vs 69.73±35.96 secs, t=1.40, P=0.016;100.95±55.92 secs vs 80.96±42.87 secs, t=3.61; P<0.001, respectively). The withdrawal time threshold in the ascending colon, transverse colon, descending colon, rectosigmoid colon determined by receiver operating characteristic (ROC) curve were 77s, 61s, 56s and 109s, respectively. In the ascending colon, ADR was significantly higher (47.0% vs 33.1%, P < 0 .001) when the colonoscopy withdrawal time was ≥77s. When the withdrawal time was ≥61s in the transverse colon (42.7% vs 32.7%, P = 0.013), ≥59s in the descending colon (42.3% vs 29.9%, P=0.004) and ≥109s in rectosigmoid colon (52.2% vs 33.9%, P < 0 .001), ADR was also significantly higher. After adjusting for age, sex and BMI, Logistic regression analysis showed that withdrawal time ≥ 77s in the ascending colon (OR, 1.796; 95% CI, 1.273-2.532; P < 0 .001), ≥ 61s in the transverse colon (OR, 1.535; 95% CI, 1.094-2.155; P = 0.013), ≥56s in the descending colon (OR, 1.722; 95%CI, 1.193-2.486; P =0.004) and ≥109s in the rectosigmoid colon (OR, 2.134; 95% CI, 1.446-2.350; P < 0.001) were independent risk factors for the increase of ADR.

Conclusion

ADR and withdrawal time are all various in individual colon segments. During the operation of colonoscopy, withdrawal time in the ascending colon may be shortened appropriately. The adenomas in the rectosigmoid colon are more likely to be detected and do not take longer withdrawal times. We need to choose the appropriate time according to different colon segments.

References

[1] Sung H, Ferlay J, Siegel R L, et al. Global cancer statistics 2020: GLOBOCAN estimates of incidence and mortality worldwide for 36 cancers in 185 countries. CA: a cancer journal for clinicians 2021;71(3): 209-249.
[2] Shaukat A, Kahi C J, Burke C A, et al. ACG clinical guidelines: colorectal cancer screening 2021. Official journal of the American College of Gastroenterology ACG 2021;116(3): 458-479.
[3] Xi Y, Xu P. Global colorectal cancer burden in 2020 and projections to 2040. Transl Oncol 2021;14(10):101174.
[4] Araghi M, Soerjomataram I, Bardot A, et al. Changes in colorectal cancer incidence in seven high-income countries: a population-based study. The lancet Gastroenterology & hepatology 2019;4(7): 511-518.
[5] Siegel RL, Torre LA, Soerjomataram I, et al. Global patterns and trends in colorectal cancer incidence in young adults. Gut 2019;68(12):2179-2185.
[6] Kaminski MF, Robertson DJ, Senore C, et al. Optimizing the Quality of Colorectal Cancer Screening Worldwide. Gastroenterology 2020;158(2):404-417.
[7] Lee JK, Jensen CD, Levin TR, et al. Long-term Risk of Colorectal Cancer and Related Deaths After a Colonoscopy With Normal Findings. JAMA Intern Med 2019;179(2):153-160.
[8] Ladabaum U, Dominitz JA, Kahi C, et al. Strategies for colorectal cancer screening. Gastroenterology 2020;158(2):418-432.

Introduction

Metabolic Associated Steatotic Liver Disease (MASLD) affects 25-30% of the European population and is projected to rise further. These patients are at increased risk for liver-related complications and higher overall mortality, emphasizing the need for early detection to improve outcomes. While abdominal ultrasound serves as the primary imaging modality for suspected liver disease, its sensitivity for diagnosing mild steatosis is inadequate, and gold-standard methods for quantifying liver steatosis infiltration, such as magnetic resonance imaging or liver biopsy are impractical for widespread use.

Aims & Methods

This study aimed to assess the diagnostic accuracy of the Attenuation Coefficient (ATT) as a complementary method to B-mode ultrasound for early detection of hepatic steatosis. Consecutive patients referred for transient elastography were prospectively enrolled. Liver steatosis was graded using a 4-point scale (normal, mild, moderate, or severe) in B-mode ultrasound for each patient, and ATT was measured in accordance with manufacturer quality criteria instructions (Fujifilm®). Additionally, the Hepato-Renal Index (HRI) was calculated for each patient, and Controlled Attenuation Parameter (CAP, Fibroscan®) was measured.

Results

A total of 128 patients, 61.7% male, with a mean age of 56.8±12.8 years, were included. Among them, 78.1% exhibited at least one cardiometabolic risk factor. The main referral indications were fibrosis assessment in viral hepatitis (42.2%), MASLD (21.9%), and alcoholic liver disease (11.7%). The median vibration-controlled elastography result was 5.8kPa. B-mode ultrasound steatosis assessment classified 44.5% as normal, 10.2% with mild steatosis, 21.1% with moderate steatosis, and 24.2% with severe steatosis. The area under the ROC curve for steatosis detection was 0.796 for HRI, 0.894 for ATT, and 0.896 for CAP, highlighting robust diagnostic performance, particularly for the latter two methods. There was a strong correlation between ATT and CAP (r=0.710). Using a CAP>248dB/m to define steatosis, the area under the ROC curve for ATT was 0.890. For an ATT cutoff value ≥0.66, Sensitivity, Specificity, Negative Predictive Value, and Positive Predictive Value were 82.7%, 77.3%, 72.3%, and 86.1%, respectively. The sensitivity of B-mode ultrasound for steatosis detection was 79.5%, increasing to 90.4% when combined with ATT measurement.

Conclusion

ATT demonstrated excellent accuracy for steatosis detection, comparable to CAP and superior to HRI. Importantly, combining B-mode ultrasound with ATT significantly improved the diagnostic sensitivity. These findings suggest that ATT has the potential to become a valuable non-invasive tool alongside ultrasound for early detection of hepatic steatosis, aiding in earlier intervention and improved patient outcomes.

References

Tamaki N, Koizumi Y, Hirooka M, et al. Novel quantitative assessment system of liver steatosis using a newly developed attenuation measurement method. Hepatol Res. 2018;48(10):821-828. doi:10.1111/hepr.13179
Bozic D, Podrug K, Mikolasevic I, Grgurevic I. Ultrasound Methods for the Assessment of Liver Steatosis: A Critical Appraisal. Diagnostics. 2022;12(10):2287. doi:10.3390/diagnostics12102287

Introduction

Invariant Natural Killer T (iNKT) cells are lipid-specific T lymphocytes endowed with antitumor activities and whose infiltration is considered a positive prognostic factor in colorectal cancer (CRC). In this context, we have previously demonstrated that, at steady state, iNKT cells eliminate human CRC cells by releasing perforin and granzyme B (1).
However, we reported that the tumor-associated pathobiont Fusobacterium nucleatum is capable of inducing IL17 and GM-CSF expression in iNKT cells, promoting iNKT-mediated recruitment of neutrophils with PMN-MDSCs- like phenotype and functions. Tumor co-infiltration by iNKT cells and neutrophils in a large cohort CRC patients of correlates with negative clinical outcomes (2). Since the gut microbiota is an oncogenic driver of CRC and intestinal microbes represent potent stimulators of iNKT cell responses we analyzed the tumor-associated mucosal microbiota of the 35 CRC patients by 16S rRNA gene sequencing, revealing the presence in a large fraction of patients of Porphyromonas gingivalis, an opportunistic oral pathobiont often associated with inflammatory diseases and cancers.

Aims & Methods

Very little is known about how the function of iNKT cells is influenced by Porphyromonas gingivalis. Our aim is to assess changes in human iNKT cell phenotype and function provoked by this bacterium, and how these changes might contribute to colon cancer progression.
Human iNKT cell phenotype, functional profile and cytotoxic capabilites were evaluated upon stimulation with P. gingivalis isolates in vitro. Subsequently, as validation, P. gingivalis was administered to AOM/DSS-treated mice and evaluated iNKT cell phenotype and tumor progression. P. gingivalis-exposed human iNKT cells were sequenced and candidate molecules were tested in vitro in killing assays with human CRC epithelial cells.

Results

We observed that, compared to cells stimulated with aGalCer (a prototypical iNKT cell antigen), iNKT cells primed with P. gingivalis showed lower levels of interferon gamma, together with impaired cytotoxicity against CRC cell lines. These cells were also characterized by an increased expression of GM-CSF, and interleukins -17 and -10, as well as an increased capability of neutrophil chemotaxis. This pro-tumorigenic phenotype was confirmed in AOM/DSS-treated mice, as P. gingivalis-treated animals showed tumors of greater size, together with an increase in IL-17+ and GM-CSF+ iNKT cells. Pg-primed iNKT cells showed an enriched neutrophil chemotaxis gene signature, which included the chemokines CXCL1, CXCL2, CXCL5, CXCL8, CCL2 and CCL4 and of proinflammatory proteins acting on the cytotoxic machinery of NKT cells inhibiting their killing functions.

Conclusion

These results demonstrate that P. gingivalis can promote colon tumorigenesis by acting on iNKT cells, both by hampering antitumor properties and promoting the release of pro-tumorigenic cytokines and chemokines, which further act on myelo-phagocytic cells.

References

1. Díaz-Basabe, A., et al. (2021). Human intestinal and circulating invariant natural killer T cells are cytotoxic against colorectal cancer cells via the perforin–granzyme pathway. Mol Oncol, 15: 3385-3403. https://doi.org/10.1002/1878-0261.13104

Introduction

Helicobacter pylori (H. pylori) infection is a common etiological cause of gastritis, peptic ulcer, atrophic gastritis, gastric adenocarcinoma, and mucosa-associated lymphoid tissue lymphoma. Accurate diagnosis and sufficient efficacy evaluation duration are both critical for effective treatment to avoid precancerous conditions.

Aims & Methods

This retrospective, observational, multicenter, real-world study (NCT05073367) was performed across 3 hospitals using a preexisting electronic medical record (EMR) database between January 1, 2019, and March 31, 2021, to evaluate the diagnosis and treatment pattern of H. pylori infection in China. The study included adult patients (aged ≥18 years) with a record of diagnostic tests or positive results of H. pylori infection. Here we analyzed the current pattern of diagnosis testing, eradication efficacy testing after eradication therapy, and the duration (≤4 or >4 weeks) from the termination of eradication therapy to efficacy evaluation testing.

Results

A total of 22,971 patients with H. pylori infection data was extracted from EMR databases. Among them, 15,712 patients had 15713 initial diagnostic testing records before the eradication therapy (One participant had both RUT testing and UBT at the index date), and 1,626 patients received efficacy evaluation after the eradication therapy. Of 15,713 initial diagnostic testing records, non-invasive testing was the main diagnostic test used by 99.99% (n=15,712) of records, and invasive testing was used by only 0.01%（n=1）. Among non-invasive testing, ¹³C- Urea breath testing (UBT) was used by 76.8% and ¹⁴C-UBT was used by 23.19%. An increasing trend was observed in the use of ¹³C-UBT diagnostic test with 47.54%, 73.20%, and 99.98% in 2019, 2020, and 2021, respectively. ¹⁴C-UBT was 52.46% in 2019，26.80% in 2020，0% in 2021.Among 1,426 patients with eradication efficacy evaluation (duration ≥ 4 weeks), non-invasive testing- UBT was the only evaluation method used, with ¹³C-UBT in 72.3% and ¹⁴C-UBT in 27.7%. In 2019, ¹³C-UBT was used by 53.69%, in 2020 it was 69.88%, and in 2021, ¹³C-UBT was the only evaluation method to assess the efficacy (Table 1). The mean (Standard Deviation) duration from the termination of eradication therapy until the eradication efficacy evaluation testing was 7.0 weeks (4.37). Of 1626 patients with efficacy evaluation, 87.7% had > 4 weeks duration and 12.3% had ≤ 4 weeks. In 2019, 83.4% had a duration of > 4 weeks, 91.21% in 2020, and in 2021, 90.68% had a duration of > 4 weeks to receive an efficacy evaluation.
Table 1. Diagnostic Testing Used Before and After Eradication Therapy

Conclusion

In China, non-invasive testing was dominant for the initial diagnosis of H. pylori infection, and ¹³C UBT was commonly used compared with ¹⁴C-UBT. The eradication efficacy evaluation testing was the same. Even over a tenth had insufficient evaluation duration, a higher proportion of evaluation duration >4 weeks was discovered with an increasing tendency.

Disclosure

The study was funded by Takeda China. Wensheng Pan, Yan Zhao, and Hongwei Xu have no conflicts of interest. Pengfei Li, Fang Zhou, and Li Xie are the employees of Takeda, and they hold Takeda stock options. Medical writing for the development of this abstract was provided by Kusuma Kumari G, Ph.D., of Indegene Private Limited, and funded by Takeda China. Authors retained full control of the abstract content.

Introduction

Colonoscopic withdrawal time is reportedly related to the adenoma detection rate (ADR) [1]. Other endoscopist-related factors that may affect ADR, such as age, sex, specialty, years of experience, and the number of endoscopies performed, have already been evaluated [2]; however, the link between ADR and the average colonoscopic caecal insertion time, which indicates proficiency in endoscopic techniques, remains unexplored [3].
The Japan Gastroenterological Endoscopy Society launched the Japan Endoscopy Database (JED) to create a large-scale endoscopy database using routine endoscopy reports. In this study, we merged the endoscopy database constructed by JED with the pathology database. To the best of our knowledge, this is the first large-scale endoscopy database in Japan that incorporates pathological data.

Aims & Methods

This study aimed to assess the impact of various endoscopist-related factors on ADR. This report is one of the main results of a Japanese multicentre observational study (J-SCOUT study) that used a colonoscopy database to evaluate factors that affect colonoscopy outcomes (No: UMIN000040690). We included all individuals aged ≥20 years who underwent colonoscopy at the participating institutions between 2010 and 2020. The exclusion criteria were as follows: (1) patient’s refusal to participate in the study; (2) colonoscopy performed within 6 months; (3) colonoscopy for previously identified colorectal lesions; (4) inflammatory bowel disease; (5) emergency endoscopy; and (6) unknown indications for colonoscopy. The following endoscopist-related factors were assessed: sex, specialty, average caecal insertion time, average withdrawal time when no polyps were found, and number of colonoscopies performed during the study period. The odds ratios of endoscopist-related factors were analysed using a generalised linear mixed model.

Results

The ADR of 47,705 colonoscopies performed by 189 endoscopists across four hospitals out of a total of 186,293 colonoscopies were analysed. Most colonoscopies were performed by gastroenterologists, with male endoscopists accounting for approximately 80%.
Compared to endoscopists with an average caecal insertion time of <5 min, those with insertion times of 5–9 min, 10–14 min, and ≥ 15 min had odds ratios of 0.84 [95% confidence interval (CI): 0.71, 0.99], 0.68 [95% CI: 0.52, 0.90], and 0.45 [95% CI: 0.25, 0.78], respectively. Compared to endoscopists with an average withdrawal time of <6 min, those with withdrawal times of 6–9 min, 10–14 min, and ≥ 15 min had odds ratios of 1.38 [95% CI: 1.03, 1.85], 1.48 [95% CI: 1.09, 2.02], and 1.68 [95% CI: 1.04, 2.61], respectively. The endoscopist’s specialty, sex, and number of examinations did not significantly affect ADR.

Conclusion

Individual mean colonoscopic withdrawal and caecal insertion times can serve as quality indicators of the procedure. These results provide a benchmark for achievable skills of endoscopists.

References

1. Barclay RL, Vicari JJ, Doughty AS et al. Colonoscopic withdrawal times and adenoma detection during screening colonoscopy. N Engl J Med 2006; 355: 2533-2541.
2. Sekiguchi M, Westerberg M, Ekbom A et al. Endoscopist characteristics and polyp detection in colonoscopy: cross-sectional analyses of screening of Swedish colons. Gastroenterology 2023; 164: 293-295.
3. Sekiguchi M, Westerberg M, Ekbom A et al. Detection rates of colorectal neoplasia during colonoscopies and their associated factors in the SCREESCO study. J Gastroenterol Hepatol 2022; 37: 2120-2130.

Disclosure

Takuji Kawamura and Yoji Takeuchi received honoraria from Olympus Corporation for lectures, presentations, or educational events.

Introduction

Large or complex colorectal polyps have a greater than average risk of malignancy, incomplete resection/recurrence or complications associated with treatment. Appropriate management is therefore crucial for preventing cancer and improving patient outcomes. UK guidelines exist for the management of large non-pedunculated colorectal polyps (LNPCPs)¹. This review aims to evaluate the case mix and outcomes from a multidisciplinary team (MDT) approach to managing such polyps.

Aims & Methods

This study is a retrospective analysis of cases referred to the Complex Polyp MDT at a single centre in the United Kingdom between January 2020 and December 2021 (two-year period). Data collected included patient characteristics, index investigation and polyp complexity as defined by the size, morphology, site, and access (SMSA) score.
Therapy details, including standard endoscopic techniques (EMR, polypectomy) and advanced options (ESD, eFTR, Endorotor), as well as trans-anal surgery, were documented. Complications and re-admission needs were recorded, along with recurrence rates at first surveillance. Any subsequent treatment for recurrence was also documented.
An electronic survey was conducted among MDT members to gather feedback on the MDT's impact on clinical practices, perceived benefits, and suggestions for improvement.

Results

Over a two-year period, 258 cases were reviewed at the complex polyp MDT, with annual cases rising from 91 to 167. After exclusions (diagnosed cancer prior to MDT, discussion regarding management of already treated polyps), 220 cases were reviewed. The median polyp SMSA score was 11, with 34% of polyps classified as level 3 and 38% as level 4. Conservative management was recommended in 35 cases, in patients with a median age of 81 (IQR 78-84), 73% of which suffered from severe systemic disease. 110 colonic polyps (62% overall) were treated with EMR. 67 rectal polyps (38%) were managed with a combination of therapies, including EMR (36, 54%), ESD (13, 19%), or trans-anal surgery (18, 27%). Only 4 complications were observed: post-polypectomy bleeding in 3 cases (from rectal EMR, colonic EMR, and trans-anal surgery) and a small perforation from a low rectal ESD. All complications were managed conservatively, and patients discharged the next day.
MDT discussion led to downgrading of 44% of cases initially deemed high-risk for malignancy; none were subsequently found to contain cancer. Three cases were upgraded to high-risk; none were found to contain cancer, but all contained high-grade dysplasia.
Of 26 patients who experienced recurrence after initial polypectomy, 17 (65%) underwent endoscopic therapy, while others either had surgical excision or were awaiting ongoing surveillance.
Of those who underwent endoscopic treatment, 16 cases (94%) were successfully treated using various techniques, such as eFTR and endoscopic mucosal debridement (Endorotor resection) via one or more further sessions. 3 of the 16 recurrent lesions contained HGD. The remaining case required right hemicolectomy for early-stage adenocarcinoma. Of note, the initial site check in that case had identified HGD.
Survey responses reflected an overall feeling of significantly improved management of complex polyps since the inception of the MDT. Improvements included increased understanding of therapeutic options and better polyp assessment amongst endoscopists.

Conclusion

Multidisciplinary team management of large or complex polyps is effective, and meets standards set by national guidance. The team approach fosters learning amongst members, leading to wide reaching improvements in practice.

References

1: Rutter MD, Chattree A, Barbour JA, Thomas-Gibson S, Bhandari P, Saunders BP, Veitch AM, Anderson J, Rembacken BJ, Loughrey MB, Pullan R. British Society of Gastroenterology/Association of Coloproctologists of Great Britain and Ireland guidelines for the management of large non-pedunculated colorectal polyps. Gut. 2015 Dec 1;64(12):1847-73.

Disclosure

No conflicts of interest.