Introduction

Cold snare polypectomy (CSP) has become popular as a safe and simple treatment for small colonic lesions. According to the Japanese guidelines, CSP is indicated for adenomas <10 mm with no suspicion of carcinoma [1]. Occasionally, colorectal carcinoma is diagnosed after resection, and there is no consensus on the treatment of such lesions [2-4].

Aims & Methods

This single-center retrospective study aimed to investigate the long-term prognosis of Japanese patients with pathologically diagnosed colorectal carcinoma after resection by CSP. Patients who underwent CSP for small colonic lesions at our hospital in 2013–2022 and were histopathologically diagnosed with colorectal carcinoma were included in this study. We examined the local residual or recurrence rate, scar detection rate, and recurrence-free survival rate in patients who underwent at least one colonoscopy after CSP.

Results

Out of 12,935 lesions (6,082 cases) that were resected using CSP during the study period, 81 lesions (0.63%; 81 cases) were histologically diagnosed as colorectal carcinoma (mean age, 69.7 years; male patients, 69% [56/81]). Histologically, all tumours were well-differentiated adenocarcinomas. Negative lateral and vertical margins of the resected specimens were 47% (38/81) and 72% (58/81), respectively. Of these 81 cases, 47 (58%) were followed up at least once by colonoscopy. The breakdown of cases that were not followed up endoscopically is as follows: concurrent advanced cancer (n=15), advanced age (n=7), dropout (n=7), and others (n=5). Endoscopic evidence of residual disease or recurrence was found in 1/47 patients (2%), and the remaining 46 patients had a median colonoscopic follow-up of 425 days (interquartile range, 192.5–1078.5 days) with no endoscopic evidence of local recurrence. In 51% (24/47) of cases, post-polypectomy scars could be identified. In one case where local residual carcinoma was confirmed, a retrospective review of the CSP revealed incomplete resection at the time of treatment. Abdominal CT performed immediately after CSP showed coincidental peritoneal dissemination, and the patient died 177 days after diagnosis. In 46 patients with no endoscopic evidence of local recurrence, the median observation period was 921 days (interquartile range, 475–1654.5 days), with six cases of death from causes other than colorectal cancer, and the others were alive without recurrence.

Conclusion

The frequency of residual disease or recurrence of colorectal carcinoma treated by CSP was low, and the long-term prognosis was favourable once the absence of residual lesions was confirmed endoscopically.

References

1. Uraoka T, Takizawa K, Tanaka S et al. Guidelines for Colorectal Cold Polypectomy (supplement to "Guidelines for Colorectal Endoscopic Submucosal Dissection/Endoscopic Mucosal Resection"). Dig Endosc 2022; 34: 668-675.
2. Yoshii S, Hayashi Y, Nakamura T et al. Endoscopic features and clinical course of colorectal carcinoma resected by cold snare polypectomy. J Gastroenterol Hepatol 2023, in press
3. Inoki K, Takamaru H, Furuhashi H et al. Management of colorectal high-grade dysplasia or cancer resected by cold snare polypectomy: a multicenter exploratory study. J Gastroenterol 2023, in press
4. Yoshida N, Fukumoto K, Hasegawa D et al. Recurrence rate and lesions characteristics after cold snare polypectomy of high-grade dysplasia and T1 lesions: A multicenter analysis. J Gastroenterol Hepatol 2021; 36: 3337-3344.

Introduction

Several studies have shown that a low quality of colonoscopy reduces its effect in preventing colorectal cancer (CRC), but it is not clear to which extent a low-quality colonoscopy is still effective compared to no colonoscopy. We aimed to compare the 13-year risk of developing CRC between persons with I) a high-quality screening colonoscopy, II) a low-quality screening colonoscopy and III) without a screening colonoscopy.

Aims & Methods

Using observational data from a German claims database (GePaRD; 20% population coverage) we emulated a target trial with three arms: High-quality screening colonoscopy (highQualSC) vs. low-quality screening colonoscopy (lowQualSC) vs. no screening colonoscopy (noSC) at baseline. The quality of baseline colonoscopy was categorized based on the polyp detection rate of the examining physician. We included persons at average CRC risk aged 55–69 years and without a colonoscopy, polypectomy or fecal occult blood test before baseline. We estimated adjusted cumulative CRC incidence over 13 years of follow-up.

Results

Overall, we included 142,960 persons in the highQualSC arm, 62,338 persons in the lowQualSC arm and 124,040 persons in the noSC arm. The adjusted 13-year risk of any CRC was 1.77% in the highQualSC arm, 2.09% in the lowQualSC arm and 2.74% in the noSC arm. Compared to the noSC arm, the adjusted relative risk (aRR) was 0.76 (95% CI: 0.70-0.84) in the lowQualSC arm and 0.65 (95% CI: 0.60-0.69) in the highQualSC arm.

Conclusion

Our study demonstrated that the effect of screening colonoscopy in preventing CRC is substantially lower in persons with a low-quality as compared to a high-quality screening colonoscopy. However, it also showed that attending a low-quality screening colonoscopy still markedly reduces the risk of CRC compared to no screening colonoscopy.

Introduction

Opium tincture in oral solution has been used for antidiarrheal treatment for centuries, and it is often used to treat chronic idiopathic diarrhea as a secondary choice after loperamide and bulking agents. However, the underlying mechanisms of opium tincture on gastrointestinal function are not evident and have not been investigated in clinical trials. This study aimed to investigate the effects of opium tincture on gastrointestinal motility, intestinal volumes, and water content of different gut segments assessed by magnetic resonance imaging (MRI).

Aims & Methods

Twenty healthy volunteers were included in a randomized, placebo-controlled, cross-over study with 9-day treatment (30 drops per day of opium tincture corresponding to 15 mg of oral morphine or placebo). MRI was performed on day 1 (before treatment) and day 9 (during treatment) using a pan-alimentary scan protocol. Images were obtained during fasting and after a 285-kcal granola bar meal. MRI measurements included assessments of gastric volume, gastric emptying half-time, gastric motility, small bowel volume, small bowel water content, small bowel motility, colon volume, colon water content, and whole gut transit. Data was analyzed using repeated measure mixed models and adjusted using baseline data as a covariate and a Bonferroni post hoc correction.

Results

The median age of the included subjects was 24 years (range 20-72 years), and 10 subjects were female. Opium tincture delayed gastric half-emptying time as compared to placebo (mean [95% confidence intervals] values: 38.5 [35.3-41.6] min vs. 32.8 [29.9-35.8] min, p=0.004). Opium tincture increased gastric meal volumes 15 and 30 minutes after the meal as compared to placebo (ps<0.018). Gastric contraction amplitude and frequency were not affected by treatment. Small bowel endpoints were not different between treatments (all p>0.05). Ascending-, transverse-, and descending colon volumes were increased after opium tincture as compared to placebo (ascending: 226 [197-253] ml vs 168 [140-195] ml, p=0.003; transverse: 208 [180-236] ml vs. 158 [131-185] ml, p=0.017; descending: 155 [125-184] ml vs. 110 [83-138] ml, p=0.045). T1-relaxation time (a proxy for water content) of the descending colon chyme was decreased during opium tincture as compared to placebo, indicating dryer feces (517 [425-609] ms vs. 690 [595-786] ms, p=0.030). Whole gut transit time was delayed during opium tincture as compared to placebo (p=0.027).

Conclusion

Opium tincture as compared to placebo induces changes in gastric and colonic motility and volumes as measured using a pan-alimentary MRI framework in a population of healthy volunteers. Based on the current results, opium tincture seems to affect the gastrointestinal tract in ways that are relevant for treating diarrhea. An improved understanding of how opioids affect gut functions may lead to a better understanding of and optimized management of diarrhea.

Introduction

Volatile organic compounds (VOCs) form a specific chemical profile that can be used to detect the colorectal cancer-related changes in human metabolism and thereby, to diagnose this type of cancer even at an early stage.

Aims & Methods

The aim of this study was to characterize the volatile chemical patterns associated with cancer and normal tissues obtained from colorectal cancer patients and identify potential volatile biomarkers of colorectal cancer. In total 50 paired tissue samples were analyzed. Volatiles released by the tissue samples were captured using solid phase microextraction (HS-SPME) and next identified and quantified using gas chromatography with mass spectrometric detection (GC-MS). A Wilcoxon signed-rank test was used to compare the emissions of VOCs from cancer and non-cancerous tissues and p<0.05 was taken as significant threshold.

Results

A total of 163 compounds were found in the headspace of the tissue samples. Amongst these, 149 VOCs were identified in cancer tissues and 147 in non-cancerous ones. 138 volatiles were found in both types of tissues. The predominant chemical classes in both tissues are hydrocarbons (25%) and alcohols (15%). These are followed by aldehydes, ketones and aromatics. Only 40 VOCs (27%) exhibited incidence higher than 50% in cancerous tissues. In case of healthy tissue this number amounted to 44 (30%). 11 volatiles occurred in at least 90% of both types of samples and thereby can be considered as omnipresent. 15 VOCs showed consistent differences in their headspace concentrations above samples under study. Of these, 4 compounds were found to have increased emissions from the cancer tissue, and the other 11 showed the reduced release from this type of samples. The species emitted in higher amounts by cancerous tissue comprised 1-propanol, pyridine, isoprene and methyl thiolacetate (p<0.05).

Conclusion

The results of this study confirm that the chemical fingerprint formed by volatiles in colorectal tissue is altered by colorectal cancer. These VOCs - 1-propanol, pyridine, isoprene, methyl thiolacetate were found to be the most promising biomarker candidates for detecting colorectal cancer.

Introduction

Post-colonoscopy colorectal cancer (PCCRC) is that diagnosed after a colonoscopy in which no cancer is found. PCCRC has become an important quality indicator. We aimed to determine its rates, characteristics, and index colonoscopy-related predictive factors.

Aims & Methods

Multicenter, observational, retrospective study between 2015 and 2018. We considered as PCCRC those developing up to 10 years after colonoscopy. PCCRC rates were calculated and PCCRC were categorized according to their most plausible explanation using the World Endoscopy Organization (WEO) methodology. Our PCCRC population was compared to a control cohort without CRC matched 1:4 by sex, age, index colonoscopy date and indication, endoscopist, and hospital.

Results

107 PCCRC were detected, of 101,524 colonoscopies (0.1%) and 2,508 CRC (4.3%), leading to rates of 0.4% (1-year), 2.2% (3-year), 3.1% (5-year), 4.1% (10-year). PCCRCs were in right (42.4%), left (41.4%), transverse (16.4%) colon with 31.5% at stage I, 24.7% stage II, 32.6% stage III, 11.2% stage IV. 20.3% of PCCRCs were classified as incomplete resection, 5.4% as unresected detected lesions, 48.6% as missed lesions with adequate colonoscopy, and 25.7% as missed lesions with inadequate colonoscopy. Mean time from previous colonoscopy to PCCRC was 42 months. Previous inadequate preparation (OR 3.05, 95%CI 1.73-5.36) and piecemeal polypectomy (OR 19.89, 95%CI 8.67-45.61) were independently associated with PCCRC.

Conclusion

In our population, 4.3% of CRCs were PCCRC. Most of these lesions were in the right colon and almost half attributable to lesions not visualized despite adequate bowel cleansing. Previous inadequate cleansing and piecemeal polypectomy were associated with PCCRC.

Disclosure

RJ has received research grants from MSD, and has participated as an advisor to MSD, Norgine, Alpha-Sigma, and GISupply. The rest of authors have nothing to disclose.

Introduction

Histopathological assessment remains the gold standard for evaluating diminutive colorectal polyps, despite the potential of optical diagnosis (OD) to reduce colonoscopy-associated costs (1). However, implementing OD strategies remains limited in clinical practice (2). This study aimed to evaluate patient acceptance of truly replacing pathology evaluation of diminutive polyps with resect and discard (RD) and diagnose and leave (DL) strategies using computer-aided polyp diagnosis (CADx).

Aims & Methods

In this prospective clinical pilot study at the Montreal University Hospital Center, 102 patients undergoing colonoscopy were invited to participate in the study. Patients received information on CADx, RD, DL and were informed that if they agree to participate in the study, we will diagnose all polyps using CADx during the colonoscopy, but polyps will be discarded or left in place and no pathology exams will be performed. For consenting patients, blue light imaging (BLI)-assisted CADx was used and endoscopists made the final histology determination and rated their confidence level (high vs. low) in the OD. Endoscopists also determined if high-risk features were present before using RD or DL strategies. Then all diminutive polyps optically diagnosed with high confidence as adenomas were resected and discarded and all diminutive rectosigmoid polyps optically diagnosed as hyperplastic with high confidence were left in situ. All polyps >5mm, with disagreement between endoscopists and CADx OD, low-confidence OD, or high-risk features (JNET 2b or higher) were sent for pathology evaluation. All cases were video recorded, and a quality review of the diagnoses performed with two expert endoscopists (DR and HP).

Results

Among the 102 patients approached, 97 (95%) accepted participating and utilization of CADx instead of pathology. Three stated that they did not want to participate in any research, and two patients stated that they did not trust OD or CADx as the reason for refusal. Overall, 164 diminutive polyps were removed in 97 patients (mean age=67.2 years), of which 36% were in the rectosigmoid and 64% in the proximal colon. CADx-assisted OD was performed on 97% of the polyps. The proportion of polyps with a low-confidence OD or disagreement between endoscopists' and CADx-based OD was 19/159 (11.9%). Overall, 98/159 (61.6%) polyps underwent the RD strategy, of which 4 polyps were discarded by the endoscopist's discretion despite disagreement between endoscopists and CADx OD. One of these 4 polyps had to undergo the DL strategy but was RD because of serrated features. One polyp in the proximal colon was resected and retrieved because of serrated features. 40 polyps were DL in the rectosigmoid, of which 1 polyp was neoplastic based on CADx and endoscopist's OD.

Conclusion

We observed a very high patient acceptance for truly replacing diminutive polyp histopathology with CADx-assisted OD. CADx-based OD was used to RD 98/159 (61.6%) or DL 40/159 (25.2%) diminutive polyps found in the cohort.

References

1) Rex, Douglas K. It’s not lack of evidence holding back resect and discard. Gastrointestinal Endoscopy, Volume 96, Issue 6, 1033 - 1035.
2) Willems P, Djinbachian R, Ditisheim S, Orkut S, Pohl H, Barkun A, Bouin M, Faulques B, von Renteln D. Uptake and barriers for implementation of the resect and discard strategy: an international survey. Endosc Int Open. 2020 May;8(5):E684-E692.

Disclosure

Dr Rex is a consultant for Olympus Corporation, Boston Scientific, Aries Pharmaceutical, Braintree Laboratories, Lumendi Ltd., Norgine, Endokey, GI Supply,
Medtronic, and Acacia Pharmaceuticals; the recipient of research support from EndoAid, Olympus Corporation, Medivators, Erbe USA Inc, and Braintree Laboratories; and a shareholder in Satisfai Health. Dr Pohl has received research funding from Steris, Cosmo, and is an advisory board member of InterVenn. Dr von Renteln has received research funding from ERBE Elektromedizin GmbH, Ventage, Pendopharm, Fujifilm, and Pentax and has received consultant or speaker fees from Boston Scientific Inc, ERBE Elektromedizin GmbH, and Pendopharm. The remaining authors disclose no conflicts.