Evidence-based clinical practice guidelines for management of colorectal polyps

White spots around colorectal tumors are cancer-related findings and may aid endoscopic diagnosis: a prospective study in Japan

BACKGROUND/AIMS

During endoscopy, white spots (WS) are sometimes observed around benign or malignant colorectal tumors; however, few reports have investigated WS, and their significance remains unknown. Therefore, we investigated the significance of WS from clinical and pathological viewpoints and evaluated its usefulness in endoscopic diagnosis.

METHODS

Clinical data of patients with lesions diagnosed as epithelial tumors from January 1, 2019, to December 31, 2020, were analyzed (n=3,869). We also performed a clinicopathological analysis of adenomas or carcinomas treated with endoscopic resection (n=759). Subsequently, detailed pathological observations of the WS were performed.

RESULTS

The positivity rates for WS were 9.3% (3,869 lesions including advanced cancer and non-adenoma/carcinoma) and 25% (759 lesions limited to adenoma and early carcinoma). Analysis of 759 lesions showed that the WS-positive lesion group had a higher proportion of cancer cases and larger tumor diameters than the WS-negative group. Multiple logistic analysis revealed the following three statistically significant risk factors for carcinogenesis: positive WS, flat lesions, and tumor diameter ≥5 mm. Pathological analysis revealed that WS were macrophages that phagocytosed fat and mucus and were white primarily because of fat.

CONCLUSIONS

WS are cancer-related findings and can become a new criterion for endoscopic resection in the future.

Risk factors and prediction model for delayed bleeding after cold snare polypectomy: a retrospective study

BACKGROUND

Delayed bleeding (DB) is a serious complication after cold snare polypectomy (CSP) for polyps in the colon. The present study aimed to investigate the incidence and risk factors of DB after CSP and to develop a risk-scoring model for predicting DB.

METHODS

A retrospective study was conducted in four Chinese medical institutions. 10650 patients underwent CSP from June 2019 to May 2023. The study analyzed the rate of DB and extracted the general clinical information and polyp-related information of patients with postoperative DB. As a control, non-DB patients who received CSP at the same 4 hospitals were analyzed. A multivariate Cox regression analysis was performed to develop the prediction model. The model was further validated using a Kaplan-Meier log-rank analysis, receiver operating characteristic curve (ROC) plot and risk plot.

RESULTS

In our study, we found a 0.24% rate of DB and the risk factors were history of hypertension, hyperlipidemia, antithrombotics use, antiplatelet use, anticoagulant use, abdominal operation, sigmoid colon lesion, hematoma, cold snare defect protrusion, polyp size, wound size, the grade of wound bleeding, and morphology of Ip. These factors were incorporated into the prediction model for DB after CSP. For 1, 3, and 5 days of bleeding, the AUC of the ROC curve was 0.912, 0.939, and 0.923, respectively. The Kaplan-Meier analysis indicated that the high-risk group had a significantly higher risk of DB than the low-risk group.

CONCLUSIONS

This study screened the risk factors and established a prediction model of DB after CSP. The results may help preventing and reducing the DB rate after CSP of colorectal polyps.

Risk Factors for Post-Endoscopic Submucosal Dissection Electrocoagulation Syndrome in Patients with Colorectal Neoplasms: A Multicenter, Large-Scale, Retrospective Cohort Study by the Honam Association for the Study of Intestinal Disease (HASID)

Background and Objectives: Colorectal endoscopic submucosal dissection (ESD) is an effective technique for removing colorectal neoplasms with large or cancerous lesions. However, there are few studies on post-ESD electrocoagulation syndrome (PECS), a complication of colorectal ESD. Therefore, this study aimed to investigate the various risk factors for PECS after colorectal ESD. Materials and Methods: We retrospectively analyzed the medical records of 1413 lesions from 1408 patients who underwent colorectal ESD at five tertiary hospitals between January 2015 and December 2020. We investigated the incidence and risk factors associated with PECS. Based on the data, we developed a risk-scoring model to predict the risk of PECS after colorectal ESD. Results: The incidence rate of PECS was 2.6% (37 patients). In multivariate analysis, the use of anti-platelet agents (odds ratio (OR), 2.474; 95% confidence interval (CI), 1.088-5.626; p < 0.031), a lesion larger than 6 cm (OR 3.755; 95% CI, 1.237-11.395; p = 0.028), a deep submucosal invasion (OR 2.579; 95% CI, 1.022-6.507; p = 0.045), and an ESD procedure time ≥ 60 min (OR 2.691; 95% CI, 1.302-5.560; p = 0.008) were independent risk factors of PECS after colorectal ESD. We developed a scoring model for predicting PECS using these four factors. As the score increased, the incidence of PECS also increased, from 1.3% to 16.6%. PECS occurred more frequently in the high-risk group (≥2) (1.8% vs. 12.4%, p < 0.001). Conclusions: In this study, the risk factors for PECS after colorectal ESD were the use of anti-platelet agents, a lesion larger than 6 cm, a deep submucosal invasion, and an ESD procedure time ≥ 60 min. The risk-scoring model developed in this study using these factors could be effective in predicting and preventing PECS.

Endoscopic submucosal dissection for colorectal neoplasms: Risk factors for local recurrence and long-term surveillance

Objectives

Endoscopic submucosal dissection (ESD) is an effective procedure for the en bloc resection of colorectal neoplasms. However, risk factors for local recurrence after ESD have not been identified. This study aimed to evaluate such risk factors after ESD for colorectal neoplasms.

Methods

This retrospective study included 1344 patients with 1539 consecutive colorectal lesions who underwent ESD between September 2003 and December 2019. We investigated various factors associated with local recurrence in these patients. The main outcomes were the incidence of local recurrence and its relationship with clinicopathological factors during long-term surveillance.

Results

The en bloc resection rate was 98.6%, the R0 resection rate was 97.2%, and the histologically complete resection rate was 92.7%. Local recurrence was observed in 7/1344 (0.5%) patients and the median follow-up period was 72 months (range 4-195 months). The incidence of local recurrence was significantly higher in lesions ≥40 mm in diameter (hazard ratio [HR] 15.68 [1.88-130.5]; p = 0.011), piecemeal resection (HR 48.42 [10.7-218.7]; p < 0.001), non-R0 resection (HR 41.05 [9.025-186.7]; p < 0.001), histologically incomplete resection (HR 16.23 [3.627-72.63]; p<0.001), and severe fibrosis (F2; HR 9.523 [1.14-79.3]; p = 0.037).

Conclusions

Five risk factors for local recurrence after ESD were identified. Patients with such factors should undergo careful surveillance colonoscopy.

Improved dual-aggregation polyp segmentation network combining a pyramid vision transformer with a fully convolutional network

Automatic and precise polyp segmentation in colonoscopy images is highly valuable for diagnosis at an early stage and surgery of colorectal cancer. Nevertheless, it still posed a major challenge due to variations in the size and intricate morphological characteristics of polyps coupled with the indistinct demarcation between polyps and mucosas. To alleviate these challenges, we proposed an improved dual-aggregation polyp segmentation network, dubbed Dua-PSNet, for automatic and accurate full-size polyp prediction by combining both the transformer branch and a fully convolutional network (FCN) branch in a parallel style. Concretely, in the transformer branch, we adopted the B3 variant of pyramid vision transformer v2 (PVTv2-B3) as an image encoder for capturing multi-scale global features and modeling long-distant interdependencies between them whilst designing an innovative multi-stage feature aggregation decoder (MFAD) to highlight critical local feature details and effectively integrate them into global features. In the decoder, the adaptive feature aggregation (AFA) block was constructed for fusing high-level feature representations of different scales generated by the PVTv2-B3 encoder in a stepwise adaptive manner for refining global semantic information, while the ResidualBlock module was devised to mine detailed boundary cues disguised in low-level features. With the assistance of the selective global-to-local fusion head (SGLFH) module, the resulting boundary details were aggregated selectively with these global semantic features, strengthening these hierarchical features to cope with scale variations of polyps. The FCN branch embedded in the designed ResidualBlock module was used to encourage extraction of highly merged fine features to match the outputs of the Transformer branch into full-size segmentation maps. In this way, both branches were reciprocally influenced and complemented to enhance the discrimination capability of polyp features and enable a more accurate prediction of a full-size segmentation map. Extensive experiments on five challenging polyp segmentation benchmarks demonstrated that the proposed Dua-PSNet owned powerful learning and generalization ability and advanced the state-of-the-art segmentation performance among existing cutting-edge methods. These excellent results showed our Dua-PSNet had great potential to be a promising solution for practical polyp segmentation tasks in which wide variations of data typically occurred.

Endoscopist-related factors affecting adenoma detection during colonoscopy: Data from the J-SCOUT study

OBJECTIVES

Colonoscopy withdrawal times are associated with the adenoma detection rate (ADR). However, the relationship between ADR and cecal insertion time has been inadequately characterized. We aimed to evaluate endoscopist-related factors involved in the ADR, including the average individual colonoscopy insertion and withdrawal times.

METHODS

This observational study used a colonoscopy database with pathology data from routine clinical practice in Japanese institutions. The odds ratios (OR) of endoscopist-related factors related to ADRs were examined using a generalized linear mixed model.

RESULTS

Of the 186,293 colonoscopies performed during the study period, 47,705 colonoscopies by 189 endoscopists in four hospitals were analyzed for ADR. The overall ADR was 38.3% (95% confidence interval [CI] 37.8, 38.7). Compared to endoscopists with mean cecal insertion times of <5 min, the OR of ADR for those with mean cecal insertion times of 5-9, 10-14, and ≥15 min were 0.84 (95% 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 mean withdrawal times of <6 min, the OR of ADR for those with mean withdrawal times of 6-9, 10-14, and ≥15 min were 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. There were no significant differences in ADRs by endoscopist specialty, gender, or the total number of examinations performed.

CONCLUSION

Individual mean colonoscopy insertion time was associated with ADR and might be considered as a colonoscopy quality indicator as well as withdrawal time.

Colorectal cancer treatment guidelines and shared decision making quality and reporting assessment: Systematic review

INTRODUCTION

Physicians must share decisions and choose personalised treatments regarding patients´ beliefs and values.

OBJECTIVE

To analyse the quality of the recommendations about shared decision making (SDM) in colorectal (CRC) and anal cancer treatment clinical practice guidelines (CPGs) and consensus statements (CSs).

METHODS

Guidelines were systematically reviewed following prospective registration (Prospero: CRD42021286146) without language restrictions searching 15 databases and 59 professional society websites from January 2010 to November 2021. A validated 31-item SDM quality assessment tool was employed to extract data in duplicate.

RESULTS

We identified 134 guidelines. Only 46/134 (34.3 %) mentioned SDM. Fifteen (11.1 %) made clear, precise and actionable recommendations, while 9/134 (6.7 %) indicated the strength of the SDM-related recommendations. CPGs underpinned by systematic reviews reported SDM more often than those based on consensus or reviews (35.9 % vs 32.0 %; p = 0.031). Guidelines that reported following quality tools (i.e., AGREE II) more commonly commented about SDM than when it was not reported (75.0 % vs 32.0 %; p = 0.003).

CONCLUSION AND PRACTICE IMPLICATIONS

Most of the CRC and anal treatment guidelines did not mention SDM and it was superficial. Guidelines based on systematic reviews and those using quality tools demonstrated better reporting of SDM. Recommendations about SDM in these guidelines merit urgent improvement.

Impact of WeChat guidance on bowel preparation for colonoscopy: a quasi-experiment study

Colonoscopy is a standard procedure for screening, monitoring, and treating colorectal lesions. To explore the impact of WeChat guidance on bowel preparation before colonoscopy. This quasi-experiment study included patients who underwent colonoscopy at Qingdao Endoscopy Center between March 2016 and September 2016. The primary outcome was bowel preparation quality (Ottawa score), the secondary outcomes were intubation time, withdrawal time, adenoma detection rate (ADR), and adverse reactions. Finally, 588 patients were included and divided into the WeChat guide (n = 295) and the non-WeChat guide (n = 293) groups, they were comparable in baseline characteristics. The Ottawa score (1.59 ± 1.07 vs. 6.62 ± 3.07, P < 0.001), intubation time (6.47 ± 1.81 vs. 11.61 ± 3.34, P < 0.001), withdrawal time (13.15 ± 3.93 vs. 14.99 ± 6.77, P < 0.001), and occurrence rate of adverse reactions (2.0% vs. 5.5%, P = 0.029) were significantly lower in the WeChat guide group than those in the non-WeChat guide group. ADR was significantly higher in the WeChat guide than that in the non-WeChat guide group (1.47 ± 2.30 vs. 0.84 ± 1.66, P < 0.001). WeChat guidance might improve the quality of bowel preparation and adenoma detection rate, shorten the time of colonoscopy, and reduce adverse reactions in bowel preparation.

Image acquisition as novel colonoscopic quality indicator: a single-center retrospective study

Purpose

In order to reduce the incidence and mortality of colorectal cancer, improving the quality of colonoscopy is the top priority. At present, the adenoma detection rate is the most used index to evaluate the quality of colonoscopy. So, we further verified the relevant factors influencing the quality of colonoscopy and found out the novel quality indicators by studying the relationship between the influencing factors and the adenoma detection rate.

Materials/methods

The study included 3824 cases of colonoscopy from January to December 2020. We retrospectively recorded the age and sex of the subjects; the number, size, and histological features of lesions; withdrawal time and the number of images acquired during colonoscopy. We analyzed the associated factors affecting adenoma and polyp detection, and verified their effectiveness with both univariate and multivariate logistic regression analyses.

Results

Logistic regression analyses showed that gender, age, withdrawal time and the number of images acquired during colonoscopy could serve as independent predictors of adenoma/polyp detection rate. In addition, adenoma detection rate (25.36% vs. 14.29%) and polyp detection rate (53.99% vs. 34.42%) showed a marked increase when the number of images taken during colonoscopy was ≥29 (P<0.001).

Conclusions

Gender, age, withdrawal time and the number of images acquired during colonoscopy are influencing factors for the detection of colorectal adenomas and polyps. And we can gain higher adenoma/polyp detection rate when endoscopists capture more colonoscopic images.

Complete endoscopic removal rate of detected colorectal polyps in a real world out-patient practical setting

OBJECTIVES

Colonoscopy with adenomatous polypectomy reduces the incidence and mortality of colorectal cancer. We introduced a strategy of removing all neoplastic polyps in single-session out-patient colonoscopy using cold polypectomy. We aimed to investigate the achievement of single-session complete removal rate of detected colorectal polyps in clinical practice.

MATERIALS AND METHODS

This retrospective study included colonoscopy-scheduled 40-79-year-old outpatients, with at least one colorectal neoplasm, between January 2015 and December 2016. Exclusion criteria were: colorectal neoplasms 21 mm or larger in size; pre-examination for colorectal surgery or endoscopic submucosal dissection; colonoscopy performed by health check program; ongoing antithrombotic treatment; inflammatory bowel disease; familial adenomatous polyposis. We defined 'clean colon' as the removal of all detected neoplastic polyps in a single-session colonoscopy. We evaluated clean colon rate, factors relating to clean colon failure and complications.

RESULTS

We evaluated 2527 patients (mean age 68 years; 799 women) with 8203 colorectal polyps (7675 adenomas, 423 serrated lesions, 105 Tis and T1 cancers). In 1-4 mm polyps, cold snare polypectomy (CSP; 51.8%) and cold forceps polypectomy (CFP; 45.8%) were applied. Clean colon rates were 95.1% per patient and 97.1% per lesion. The significant factors denoting clean colon failure were inadequate bowel preparation, ≥5 lesions, and the most advanced estimated histology of adenocarcinoma, on multivariate analyses. Post-polypectomy bleeding requiring endoscopic hemostasis occurred in five patients (0.2%) who had undergone endoscopic mucosal resection (EMR) or hot snare polypectomy (HSP). Perforation occurred in one patient (0.04%) with EMR.

CONCLUSIONS

The clean colon rates were satisfactory in single-session out-patient colonoscopy using cold polypectomy.

Through the Looking Glass: Surveillance Following Colonoscopic Polypectomy of Malignant Polyps

Introduction Colonoscopic polypectomy is a well-established screening and surveillance modality for malignant colorectal polyps. Following the detection of a malignant polyp, patients are either put on endoscopic surveillance or planned for a surgical procedure. We studied the outcome of colonoscopic excision of malignant polyps and their recurrence rates. Methods We performed a retrospective analysis over a period of five years (2015-2019) of patients who underwent colonoscopy and resection of malignant polyps. Size of polyp, follow-up with tumour markers, CT scan, and biopsy were considered individually for pedunculate and sessile polyps. We analysed the percentage of patients who underwent surgical resection, the percentage of patients who were managed conservatively, and the percentage of recurrence post-excision of malignant polyps. Results A total of 44 patients were included in the study. Of the 44 malignant polyps, most were present in the sigmoid colon at 43% (n=19), with the rectum containing 41% (n=18). The ascending colon accounted for 4.5% (n=2), transverse colonic polyps were 7% (n=3), and the descending colon polyps were 4.5% (n=2). Pedunculated polyps made up 55% (n=24). These were Level 1-3 based on Haggits classification; 14 were Haggits Level 1, eight were Haggits Level 2, and two were Haggits Level 3. The rest were sessile polyps making up 45% (n=20). Based on the Kikuchi classification, these were predominantly SM1 (n=12) and SM2 (n=8). Out of 44 cases, 11% (n=5) underwent surgical resection on follow-up in the form of bowel resection. This included three right hemicolectomies, one sigmoid colectomy, and one low anterior resection. Seven per cent (n=3) underwent endoscopic resection as trans-anal endoscopic mucosal resection (TEMS) and 82% (n=36) of the remaining cases were managed with regular follow-up and surveillance. Conclusions Colonoscopic polypectomy offers excellent benefits in detecting colorectal cancer and treating pre-malignant polyps. Colonoscopic polypectomy provides excellent benefits in colorectal cancer (CRC) detection and treatment of malignant polyps. However, it remains to be seen if post-polypectomy surveillance for low-risk polyp cancers would require a change in surveillance.

Clinicopathological features and expression of regulatory mechanism of the Wnt signaling pathway in colorectal sessile serrated adenomas/polyps with different syndrome types

BACKGROUND

Colorectal cancer (CRC) is the third most common cancer worldwide, with the fourth highest mortality among all cancers. Reportedly, in addition to adenomas, serrated polyps, which account for 15%-30% of CRCs, can also develop into CRCs through the serrated pathway. Sessile serrated adenomas/polyps (SSAs/Ps), a type of serrated polyps, are easily misdiagnosed during endoscopy.

AIM

To observe the difference in the Wnt signaling pathway expression in SSAs/Ps patients with different syndrome types.

METHODS

From January 2021 to December 2021, patients with SSAs/Ps were recruited from the Endoscopy Room of Shanghai Traditional Chinese Medicine-Integrated Hospital, affiliated with Shanghai University of Traditional Chinese Medicine. Thirty cases each of large intestine damp-heat (Da-Chang-Shi-Re, DCSR) syndrome and spleen-stomach weakness (Pi-Wei-Xu-Ruo) syndrome were reported. Baseline comparison of the general data, typical tongue coating, colonoscopy findings, and hematoxylin and eosin findings was performed in each group. The expression of the Wnt pathway-related proteins, namely β-catenin, adenomatous polyposis coli, and mutated in colorectal cancer, were analyzed using immunohistochemistry.

RESULTS

Significant differences were observed with respect to the SSAs/Ps size between the two groups of patients with different syndrome types (P = 0.001). The other aspects did not differ between the two groups. The Wnt signaling pathway was activated in patients with SSAs/Ps belonging to both groups, which was manifested as β-catenin protein translocation into the nucleus. However, SSAs/Ps patients with DCSR syndrome had more nucleation, higher β-catenin expression, and negative regulatory factor (adenomatous polyposis coli and mutated in colorectal cancer) expression (P < 0.0001) than SSA/P patients with Pi-Wei-Xu-Ruo syndrome. In addition, the SSA/P size was linearly correlated with the related protein expression.

CONCLUSION

Patients with DCSR syndrome had a more obvious Wnt signaling pathway activation and a higher risk of carcinogenesis. A high-quality colonoscopic diagnosis was essential. The thorough assessment of clinical diseases can be improved by combining the diseases of Western medicine with the syndromes of traditional Chinese medicine.

Bleeding Risk With Cold Snare Polypectomy of ≤10 mm Pedunculated Colon Polyps

OBJECTIVES

Pedunculated polyps (PPs) in the colon are usually resected with hot snare polypectomy to prevent immediate postpolypectomy bleeding (IPPB). This study aimed to evaluate the safety of CSP of <10 mm PPs.

MATERIALS AND METHODS

Patients undergoing colonoscopy from February 18, 2019, to April 24, 2020, and were found to have at least 1 ≤10 mm PP resected with CSP were included prospectively in a continuous quality improvement project to assess the risk of IPPB and delayed postpolypectomy bleeding. Polyp location, size, and pathology, as well as the method of resection, were recorded. In addition, we assessed the occurrence and severity of IPPB and the need for intervention.

RESULTS

We found 239 eligible polyps in 182 patients. The mean (SD) age was 58.8 (8.3) years, and 61% were males. IPPB occurred in 72 of 239 polyps, corresponding to a per-polyp bleeding percentage of 30.1% and in 65 of 182 patients, equating to a per-patient bleeding rate of 35.7%. We successfully treated bleeding by endoscopic hemostasis in 57%; the remaining 31 polyps (43%) did not require endoscopic intervention. There was no association between IPPB with age, gender, or use of aspirin or antithrombotic agents. In the bivariate model, polyp size and pathology were not associated with the risk of IPPB. Right-sided polyps were associated with a reduced risk of IPPB in the bivariate model by 61% (odds ratio=0.39; 95% confidence interval, 0.21-0.74; P =0.0057). In the multivariate model, choking the polyp base decreased the likelihood of IPPB by 97% (odds ratio=0.03; 95% confidence interval, 0.00-0.86; P =0.0459). There were no instances of delayed bleeding, perforation, or postpolypectomy syndrome.

CONCLUSIONS

CSP can be used for resection of ≤10 mm PPs. It is associated with a lower risk of immediate bleeding than the common perception among gastroenterologists.

[Prevention of bleeding in polypectomy]

OBJECTIVE

To improve early treatment outcomes in patients with gastrointestinal polyps using a new device designed for prevention of bleeding during endoscopic minimally invasive polypectomy.

MATERIAL AND METHODS

A prospective trial included 35 patients with 36 colonic polyps (stalk diameter >5 mm). Polyp ligation procedure was performed using a novel device providing delivery and tightening the knot before polypectomy.

RESULTS

All polyps were successfully removed without any technical difficulties and exposed to histological examination. Mean age of patients was 64 years (52-81), mean dimension of polyps - 15.6 mm (10-40), mean thickness of stalk - 8 mm (5-12). There were no intraoperative and early postoperative complications. All patients were discharged after 2 postoperative days.

CONCLUSION

The proposed method for prevention of bleeding during polypectomy is simple, effective and safe for clinical practice.

Appendectomy Is Oncologically Equivalent to Right Hemicolectomy for Well-Differentiated T1 Appendiceal Adenocarcinoma

BACKGROUND

Right hemicolectomy is recommended for appendiceal adenocarcinoma but may not be needed for early stage disease.

OBJECTIVE

This study aimed to determine whether appendectomy offers adequate oncologic outcomes for T1 appendiceal adenocarcinoma from a national cohort of patients.

DESIGN

Patients with T1 appendiceal adenocarcinoma (mucinous and nonmucinous histology) treated with either a right hemicolectomy or appendectomy between 2004 and 2016 were retrieved. Multivariate Cox regression analysis was used to identify predictors of overall survival.

SETTING

The study was conducted using a national cancer database.

PATIENTS

A total of 320 patients (median age, 62 y; 47% women) were identified: 69 (22%) underwent an appendectomy and 251 (78%) underwent a right hemicolectomy.

MAIN OUTCOME MEASURE

Overall survival was measured.

RESULTS

Nonmucinous adenocarcinoma was identified in 194 (61%), whereas 126 (39%) had mucinous adenocarcinoma. Of the overall cohort, 43% had well-differentiated histology, 39% had moderately differentiated disease, and 4% had poorly differentiated tumors. The rate of lymph node metastasis was lower in well-differentiated tumors (3%) compared with moderately (10%) or poorly differentiated tumors (25%). On univariate survival analysis, right hemicolectomy was associated with improved 1-, 3-, and 5-year overall survival in patients with moderately/poorly differentiated disease ( p < 0.001) but not for well-differentiated disease ( p = 1.000). After adjustment, right hemicolectomy was associated with overall survival improvement for moderately/poorly differentiated T1 adenocarcinoma (HR = 0.26 [95% CI, 0.08-0.82]; p = 0.02) but not for well-differentiated disease.

LIMITATIONS

This study was limited by its retrospective nature.

CONCLUSIONS

The current analysis from the National Cancer Database demonstrates that appendectomy is associated with equivalent survival to right hemicolectomy for well-differentiated T1 adenocarcinoma, whereas for moderately and poorly differentiated disease, right hemicolectomy is oncologically superior to appendectomy. See Video Abstract at http://links.lww.com/DCR/B689 .

LA APENDICECTOMA ES ONCOLGICAMENTE EQUIVALENTE A LA HEMICOLECTOMA DERECHA PARA EL ADENOCARCINOMA APENDICULAR T BIEN DIFERENCIADO

ANTECEDENTES:La hemicolectomía derecha se recomienda para el adenocarcinoma apendicular, pero puede no ser necesaria para la enfermedad en estadio temprano.OBJETIVO:Este estudio tuvo como objetivo determinar si la apendicectomía ofrece resultados oncológicos adecuados para el adenocarcinoma apendicular T1 de una cohorte nacional de pacientes.DISEÑO:Se recuperaron pacientes con adenocarcinoma apendicular T1 (histología mucinoso y no mucinoso) tratados con hemicolectomía derecha o apendicectomía entre 2004-2016. Se utilizó un análisis de regresión de Cox multivariante para identificar los predictores de la supervivencia global.ENTORNO CLÍNICO:Base de datos nacional sobre cáncer.PACIENTES:Se identificaron un total de 320 pacientes (mediana de edad 62 años, 47% mujeres): 69 (22%) se sometieron a una apendicectomía y 251 (78%) se sometieron a una hemicolectomía derecha.PRINCIPAL MEDIDA DE RESULTADO:Sobrevida global.RESULTADOS:Se identificó adenocarcinoma no mucinoso en 194 (61%) mientras que 126 (39%) tenían adenocarcinoma mucinoso. De la cohorte general, el 43% tenía una histología bien diferenciada, el 39% tenía una enfermedad moderadamente diferenciada y el 4% tenía tumores poco diferenciados. La tasa de metástasis en los ganglios linfáticos fue menor en los tumores bien diferenciados (3%) en comparación con los tumores moderadamente (10%) o pobremente diferenciados (25%). En el análisis de sobrevida univariante, la hemicolectomía derecha se asoció con una mejor sobrevida general a 1, 3, y 5 años en pacientes con enfermedad moderada / pobremente diferenciada ( p < 0,001) pero no para la enfermedad bien diferenciada ( p = 1,000). Después del ajuste, la hemicolectomía derecha se asoció con una mejora de la sobrevida general para el adenocarcinoma T1 moderadamente / poco diferenciado (HR = 0,26, IC del 95%: 0,08-0,82, p = 0,02) pero no para la enfermedad bien diferenciada.LIMITACIONES:Este estudio estuvo limitado por su naturaleza retrospectiva.CONCLUSIONES:El análisis actual de la base de datos nacional de cáncer demuestra que la apendicectomía se asocia con una sobrevida similar a la hemicolectomía derecha para el adenocarcinoma T1 bien diferenciado, mientras que para la enfermedad moderada y pobremente diferenciada, la hemicolectomía derecha es oncológicamente superior a la apendicectomía. Consulte Video Resumen en http://links.lww.com/DCR/B689 . (Traducción-Dr. Yazmin Berrones-Medina ).

"Endoscopic" adenoma detection rate as a quality indicator of colonoscopy: First report from the J-SCOUT study

OBJECTIVES

To examine whether reasonable detection rate of endoscopically diagnosed lesions as adenoma ("endoscopic" adenoma detection rate [ADR]) could be calculated with a database generated from colonoscopy reports and whether it could be used as a surrogate colonoscopy quality indicator of "pathological" ADR.

METHODS

A lesion-by-lesion database of colonoscopies performed between 2010 and 2020 at eight Japanese endoscopy centers and corresponding pathology database were integrated. Differences in numbers of detected polyps, "endoscopic" and "pathological" adenomas, and what these differences could be attributed to were examined. Polyp detection rate (PDR), "endoscopic" and "pathological" ADRs, and correlation coefficients between "pathological" ADR and PDR or "endoscopic" ADR by each endoscopist were calculated.

RESULTS

Overall, 129,065 colonoscopy reports were analyzed. Among a total of 146,854 polyps, more "endoscopic" adenomas (n = 117,359) were observed than "pathological" adenomas (n = 70,076), primarily because adenomas were not resected on site, rather than because of a misdiagnosis. In all patients analyzed, PDR, "endoscopic" and "pathological" ADRs were 56.4% (95% confidence interval [CI] 56.2-56.7), 48.0% (95% CI 47.7-48.3), and 32.7% (95% CI 32.5-33.0), respectively. "Endoscopic" and "pathological" ADRs from each endoscopist showed a high correlation in hospitals where adenomas were usually resected at the time of examination.

CONCLUSIONS

By appropriately describing endoscopically diagnosed lesions as "adenomas" in endoscopy reports, "endoscopic" ADR might be used as a surrogate colonoscopy quality indicator of "pathological" ADR (UMIN000040690).

Systematic review of shared decision-making in guidelines about colorectal cancer screening

INTRODUCTION

We aimed to systematically evaluate quality of shared decision-making (SDM) in colorectal cancer (CRC) screening clinical practice guidelines (CPGs) and consensus statements (CSs).

METHODS

Search for CRC screening guidances was from 2010 to November 2021 in EMBASE, Web of Science, MEDLINE, Scopus and CDSR, and the World Wide Web. Three independent reviewers and an arbitrator rated the quality of each guidance using a SDM quality assessment tool (maximum score: 31). Reviewer agreement was 0.88.

RESULTS

SDM appeared in 41/83 (49.4%) CPGs and 9/19 (47.4%) CSs. None met all the quality criteria, and 51.0% (52/102) failed to meet any quality items. Overall compliance was low (mean 1.63, IQR 0-2). Quality was better in guidances published after 2015 (mean 1, IQR 0-3 vs. mean 0.5, IQR 0-1.5; p = 0.048) and when the term SDM was specifically reported (mean 4.5, IQR 2.5-4.5 vs. mean 0.5, IQR 0-1.5; p < 0.001). CPGs underpinned by systematic reviews showed better SDM quality than consensus (mean 1, IQR 0-3 vs. mean 0, IQR 0-2, p = 0.040).

CONCLUSION

SDM quality was suboptimal and mentioned in less than half of the guidances, and recommendations were scarce. Guideline developers should incorporate evidence-based SDM recommendations in guidances to underpin the translation of evidence into practice.

Post-polypectomy surveillance: the present and the future

An appropriate post-polypectomy surveillance program requires the effectiveness of reducing colorectal cancer and safety. In addition, the post-polypectomy surveillance program should consider the burden of limited medical resource capacity, cost-effectiveness, and patient adherence. In this sense, a risk-stratified surveillance program based on baseline colonoscopy results is ideal. Major international guidelines for post-polypectomy surveillance, such as those from the European Union and the United States, have recommended risk-stratified surveillance programs. Both guidelines have recently been updated to better differentiate between high- and low-risk individuals. In both updated guidelines, more individuals have been downgraded to lower-risk groups that require less frequent or no surveillance. Furthermore, increased attention has been paid to the surveillance of patients who undergo serrated polyp removal. Previous guidelines in Japan did not clearly outline the risk stratification in post-polypectomy surveillance. However, the new colonoscopy screening and surveillance guidelines presented by the Japan Gastroenterological Endoscopy Society include a risk-stratified post-polypectomy surveillance program. Further discussion and analysis of unresolved issues in this field, such as the optimal follow-up after the first surveillance, the upper age limit for surveillance, and the ideal method for improving adherence to surveillance guidelines, are warranted.

TGF-β-induced FLRT3 attenuation is essential for cancer-associated fibroblast-mediated epithelial-mesenchymal transition in colorectal cancer

Cancer-associated fibroblasts (CAFs) constitute a major component of the tumor microenvironment. The effects of CAFs on the progression of colorectal cancer (CRC) remain controversial. In this study, we found the ectopic overexpression of Fibronectin leucine-rich transmembrane protein 3 (FLRT3) inhibited the process of Epithelial-mesenchymal transition (EMT), as well as the proliferation, migration, invasion, and promote apoptosis of CRC cells, whereas silencing FLRT3 expression resulted in the opposite phenomenon. FLRT3 downregulation was associated with a poor prognosis in CRC. Also, FLRT3 expression was significantly related to some clinicopathological factors, including T stage (p=0.037), N stage (p=0.042), and E-cadherin (p=0.002) level. Via univariate and multivariate analyses, M stage (p<0.0001), FLRT3 (p=0.044), and E-cadherin (p=0.003) were associated with overall survival and were independent prognostic factors for it. Mechanistically, CAFs secreted TGF-β, which downregulated FLRT3 expression by activating SMAD4 to promote aggressive phenotypes in CRC cells. Moreover, FLRT3 repressed tumorigenesis and lung metastasis, which could be reversed by LY2109761, a dual inhibitor of TGF-β receptor type I and II. Treatment with LY2109761 increased IFN-γ expression in CD8+ T cells and reduced the number of regulatory T cells in the tumor microenvironment. Taken together, we revealed the metastasis-suppressive function of FLRT3, which was attenuated during the CAFs-mediated activation of the TGF-β/SMAD4 signaling pathway to promote EMT in CRC. LY2109761 that significantly inhibited metastasis could be a new treatment option for advanced CRC. Implications: CAFs enhance CRC aggressiveness by reducing FLRT3 expression through activating TGF-β/SMAD4 signaling pathway. CAFs-targeted therapy and/or LY2109761 were promising treatments for CRC.

Clinicopathological characteristics of colorectal serrated polyposis syndrome (SPS): results of a multicenter study by the SPS Study Group in Japan

BACKGROUND

Serrated polyposis syndrome (SPS), a type of colorectal polyposis characterized by multiple serrated polyps, is associated with a high risk of colorectal carcinoma (CRC). This study aimed to clarify the clinicopathological characteristics of SPS in Japan.

METHODS

We investigated the clinicopathological characteristics of patients with SPS from the "Multicenter Study on Clinicopathological Characteristics of SPS (UMIN 000032138)" by the Colorectal Serrated Polyposis Syndrome (SPS) Study Group. In this study, patients were diagnosed with SPS based on the 2019 World Health Organization (WHO) SPS diagnostic criteria.

RESULTS

Ninety-four patients were diagnosed with SPS in 10 institutions between January 2001 and December 2017. The mean number (± standard deviation [SD]) of resected lesions per patient was 11.3 ± 13.8. The mean age at diagnosis of SPS was 63.3 ± 11.6 years, and 58 patients (61.7%) were male. Eighty-seven (92.6%) and 16 (17.0%) patients satisfied WHO diagnostic criteria I and II, respectively. Nine patients (9.6%) satisfied both criteria I and II. Carcinoma (T1-T4) were observed in 21 patients (22.3%) and 24 lesions. Of the 21 patients with CRC, 19 (90.4%) satisfied diagnostic criterion I, 1 (4.8%) satisfied diagnostic criterion II, and 1 (4.8%) satisfied diagnostic criteria I and II. There was no notable difference in the prevalence of CRC among patients who met diagnostic criterion I, II, and both I and II.

CONCLUSIONS

Patients with SPS have a high risk of CRC and should undergo regular surveillance colonoscopy. Raising awareness of this syndrome is crucial.

Cost-effectiveness analysis of endoscopic resection for colorectal laterally spreading tumors: Endoscopic submucosal dissection versus piecemeal endoscopic mucosal resection

OBJECTIVES

The cost-effectiveness of endoscopic submucosal dissection (ESD) and piecemeal endoscopic mucosal resection (pEMR) for colorectal laterally spreading tumors (LSTs) remains unclear. We examined the cost-effectiveness of these procedures for cases of colon/rectal LST-non-granular-type ≥2 cm and LST-granular-mixed-type ≥3 cm.

METHODS

We performed a simulation model analysis using parameters based on clinical data from the National Cancer Center Hospital, Tokyo, and previous literature. The number of recurrences and surgeries and the required costs for 5 years following ESD and pEMR were assessed. Japanese cost data were used in the base-case analysis, and probabilistic sensitivity analysis (PSA) was performed. The Swedish cost data were used in the scenario analysis.

RESULTS

Endoscopic submucosal dissection yielded a considerably lower number of recurrences and surgeries but required a higher cost than pEMR. The recurrence rates following ESD and pEMR were 0.9-1.3% and 21.1-25.9%, respectively. The incremental cost-effectiveness ratios for an avoided recurrence and surgery for ESD against pEMR were 376,796-476,496 JPY (3575-4521 USD) and 7,335,436-8,187,476 JPY (69,604-77,689 USD), respectively. PSA demonstrated that the probability of ESD being chosen as a more cost-effective option than pEMR was >50% at willingness-to-pay values of ≥400,000-500,000 JPY (3795-4744 USD) for avoiding a recurrence and ≥9,500,000-10,500,000 JPY (90,143-99,631 USD) for avoiding a surgery. In the scenario analysis, the required cost was also lower for ESD.

CONCLUSIONS

Our findings suggest potentially favorable cost-effectiveness of ESD, depending on cost settings and the willingness-to-pay value for avoiding recurrence/surgery.

Evaluation of cold snare polypectomy for small pedunculated (Ip) polyps with thin stalks: a prospective clinical feasibility study

BACKGROUND

Although the use of cold snare polypectomy (CSP) has spread rapidly, no prospective studies evaluating the safety of CSP for pedunculated (Ip) polyps have been carried out.

AIM

We performed this study to provide an accurate evaluation of the safety of CSP for Ip polyps.

METHODS

This is a prospective study (UMIN000035687). From January 2019 to February 2021, the safety of CSP for use on Ip polyps <10 mm with thin stalks was evaluated at our hospital. The primary outcome measure was the incidence of bleeding (delayed post-polypectomy bleeding (DPPB) and immediate bleeding).

RESULTS

During the study period, 89 consecutive patients (including 92 colonoscopies and 114 polyps) were prospectively enrolled. The en-bloc resection rate was 100%. The rate of DPPB after CSP was 0%, however, DPPB after conversion to HSP occurred in 1 case (33.3% (1/3)). The rate of immediate bleeding during CSP was 28.9% (33/114). Polyps with diameters ≥6 mm (OR (95% CI): 2.77 (1.041-7.376); p = .041) were extracted as independent risk factors for immediate bleeding during CSP for Ip polyps. In all, 104 (91.2%) polyps were low-grade adenomas, and the percentage of cases with negative pathological margins was 96.5% (110/114).

CONCLUSIONS

CSP for Ip polyps was safe and had good outcomes. We believe that Ip polyps could be included as an indication for CSP, and that CSP may become the next step in the 'cold revolution.' To confirm our results and verify CSP's inclusion in future guidelines, prospective, randomized studies are necessary.

Impact of the clinical use of artificial intelligence-assisted neoplasia detection for colonoscopy: a large-scale prospective, propensity score-matched study (with video)

BACKGROUND AND AIMS

Recently, the use of computer-aided detection (CADe) for colonoscopy has been investigated to improve the adenoma detection rate (ADR). We aimed to assess the efficacy of a regulatory-approved CADe in a large-scale study with high numbers of patients and endoscopists.

METHODS

This was a propensity score-matched prospective study that took place at a university hospital between July 2020 and December 2020. We recruited patients aged ≥20 years who were scheduled for colonoscopy. Patients with polyposis, inflammatory bowel disease, or incomplete colonoscopy were excluded. We used a regulatory-approved CADe system and conducted a propensity score matching-based comparison of the ADR between patients examined with and without CADe as the primary outcome.

RESULTS

During the study period, 2261 patients underwent colonoscopy with the CADe system or routine colonoscopy, and 172 patients were excluded in accordance with the exclusion criteria. Thirty endoscopists (9 nonexperts and 21 experts) were involved in this study. Propensity score matching was conducted using 5 factors, resulting in 1836 patients included in the analysis (918 patients in each group). The ADR was significantly higher in the CADe group than in the control group (26.4% vs 19.9%, respectively; relative risk, 1.32; 95% confidence interval, 1.12-1.57); however, there was no significant increase in the advanced neoplasia detection rate (3.7% vs 2.9%, respectively).

CONCLUSIONS

The use of the CADe system for colonoscopy significantly increased the ADR in a large-scale prospective study including 30 endoscopists (Clinical trial registration number: UMIN000040677.).

Large polyps: Pearls for the referring and receiving endoscopist

Polyps are precursors to colorectal cancer, the third most common cancer in the United States. Large polyps, i.e.,, those with a size ≥ 20 mm, are more likely to harbor cancer. Colonic polyps can be removed through various techniques, with the goal to completely resect and prevent colorectal cancer; however, the management of large polyps can be relatively complex and challenging. Such polyps are generally more difficult to remove en bloc with conventional methods, and depending on level of expertise, may consequently be resected piecemeal, leading to an increased rate of incomplete removal and thus polyp recurrence. To effectively manage large polyps, endoscopists should be able to: (1) Evaluate the polyp for characteristics which predict high difficulty of resection or incomplete removal; (2) Determine the optimal resection technique (e.g., snare polypectomy, endoscopic mucosal resection, endoscopic submucosal dissection, etc.); and (3) Recognize when to refer to colleagues with greater expertise. This review covers important considerations in this regard for referring and receiving endoscopists and methods to best manage large colonic polyps.

Acromegaly and the Colon: Scoping Beyond the Pituitary

Acromegaly is a complex endocrinological disorder commonly caused by hypersecretion of growth hormone (GH) typically due to pituitary gland tumors. Patients with acromegaly who are successfully treated and biochemically managed have a reasonably average life expectancy. However, it causes a cascade of multi-systemic involvement throughout the patient's life, including cardiovascular, neuropsychiatric, respiratory, metabolic, neurological, neoplastic, and gastrointestinal involvement, resulting in a higher rate of hospitalization, lower quality of life, and a shorter life expectancy. Although cardiovascular complications are the primary cause of death in patients with acromegaly, malignancy is now emerging as a major killer in these individuals. Colorectal carcinoma has been reported to be prevalent in acromegaly individuals. This review article has compiled studies to demonstrate a link between acromegaly and colorectal neoplasia, intending to provide a strong foundation for their clinical relationship. This article has summarised a potential pathogenic mechanism and provided insights into the clinical presentation of such patients. Furthermore, this article has provided a brief overview of current screening recommendations for colorectal neoplasia in acromegaly patients.

Long-term cumulative incidence of metachronous advanced colorectal neoplasia after colonoscopy and a novel risk factor: a cohort study

BACKGROUND AND AIM

Long-term cumulative incidence of and risk factors for metachronous advanced colorectal neoplasia, including both advanced colorectal adenoma (≥10 mm, or with villous or high-grade dysplasia) and colorectal cancer, are critical for surveillance strategies. The aim of this study was to determine the cumulative incidence of metachronous advanced colorectal neoplasia and its risk factors.

METHODS

A retrospective cohort study was conducted on 6720 consecutive individuals who underwent general health check-ups and colonoscopy. Colorectal adenomas at initial colonoscopy were categorized as low-risk (1-2 small [<10 mm] tubular adenomas) or high-risk adenoma (≥3 tubular adenomas of any size; at least one adenoma ≥10 mm; or villous adenoma or adenoma with high-grade dysplasia). Kaplan-Meier estimates and hazard ratio by Cox-proportional hazard regression were calculated.

RESULTS

The cumulative incidence (95% confidence interval [CI]) of metachronous advanced colorectal neoplasia at 5 and 10 years was 5.7% [4.6-7.1], and 11% [8.9-14] in the low-risk adenoma group, and 10% [8.6-13], and 17% [14-21] in high-risk adenoma group, respectively. Adjusted hazard ratio [95% CI] of low-risk adenoma (vs. no colorectal adenoma), high-risk adenoma (vs. no colorectal adenoma), current smoking and positive fecal immunochemical test were 1.34 [1.04-1.74], 1.94 [1.48-2.55], 1.55 [1.2-2.02] and 1.69 [1.35-2.1], respectively. Adjusted hazard ratio [95% CI] of positive fecal immunochemical test was 1.88 [1.29-2.74] in those with normal colonoscopy.

CONCLUSIONS

Both low-risk and high-risk adenomas confer substantial risk for metachronous advanced colorectal neoplasia at 10 years. Positive fecal immunochemical test was a significant risk factor for metachronous advanced colorectal neoplasia despite normal colonoscopy.

Evolving management of colorectal polyps

Advances in endoscopic technology have led to increased success in colorectal cancer (CRC) screening and polyp management, with reduction of CRC incidence and mortality. Despite these advances, CRC is still one of the leading causes of cancer deaths, and half of all CRC develops from lesions that were missed during colonoscopy while one-fifth of CRC arise from prior incomplete resection. Techniques to improve polyp detection are needed, along with optimization of complete resection of any abnormal lesions that are found. This article will review the currently available endoscopic resection techniques and will discuss where they fit in the management of polyps of different sizes and types, such as pedunculated versus nonpedunculated, and those with or without suspected invasion.

Complications of colonoscopy in Japan: An analysis using large-scale health insurance claims data

BACKGROUND AND AIM

In Japan, screening colonoscopy for colorectal cancer is expected to reduce colorectal cancer mortality, although its complication rate has not been sufficiently examined. The aim of this study is to analyze severe complications due to colonoscopy.

METHODS

As a study population, we retrospectively used commercially anonymized health insurance claims data covering 5.71 million patients from January 2005 to August 2018. We extracted patients who received colonoscopy with lesions resection or without treatment. Main outcomes were rates of hemorrhage, perforation, fatal events, and their risk factors.

RESULTS

Among 341 852 colonoscopy without treatment in 260 128 patients (mean age: 49.6 ± 11.7 years), the rates of hemorrhage, perforation, and fatal events were 0.0059% (95% confidence interval [CI] 0.0031-0.0085), 0.0032% (95% CI 0.0011-0.0052), and 0.00029% (95% CI 0-0.0012), respectively. Regarding hemorrhage, compared with the rate for patients <50 years old (0.0050%), the rates for those 50-59, 60-69, and ≥70 years old were 0.0095% (P = 0.17), 0.0031% (P = 0.17), and 0%, respectively. Regarding perforation, compared with patients <50 years old (0.0056%), the rates for those 50-59, 60-69, and ≥70 years old were 0%, 0.0015% (P = 0.99), and 0.0102% (P = 0.99), respectively. A multivariate analysis for risk factors showed no significant findings for hemorrhage and perforation without treatment. Among 123 087 colonoscopy with lesions resection in 102 058 patients (mean age: 53.7 ± 9.3 years), the rates of hemorrhage, perforation, and fatal events were 0.136% (95% CI 0.1157-0.1572), 0.033% (95% CI 0.0228-0.0437), and 0.00081% (95% CI 0-0.0035), respectively.

CONCLUSIONS

The analysis using health insurance claims data demonstrated the safety of colonoscopy.

Artificial intelligence-assisted colonoscopy: A prospective, multicenter, randomized controlled trial of polyp detection

BACKGROUND

Artificial intelligence (AI) assistance has been considered as a promising way to improve colonoscopic polyp detection, but there are limited prospective studies on real-time use of AI systems.

METHODS

We conducted a prospective, multicenter, randomized controlled trial of patients undergoing colonoscopy at six centers. Eligible patients were randomly assigned to conventional colonoscopy (control group) or AI-assisted colonoscopy (AI group). AI assistance was our newly developed AI system for real-time colonoscopic polyp detection. Primary outcome is polyp detection rate (PDR). Secondary outcomes include polyps per positive patient (PPP), polyps per colonoscopy (PPC), and non-first polyps per colonoscopy (PPC-Plus).

RESULTS

A total of 2352 patients were included in the final analysis. Compared with the control, AI group did not show significant increment in PDR (38.8% vs. 36.2%, p = 0.183), but its PPC-Plus was significantly higher (0.5 vs. 0.4, p < 0.05). In addition, AI group detected more diminutive polyps (76.0% vs. 68.8%, p < 0.01) and flat polyps (5.9% vs. 3.3%, p < 0.05). The effects varied somewhat between centers. In further logistic regression analysis, AI assistance independently contributed to the increment of PDR, and the impact was more pronounced for male endoscopists, shorter insertion time but longer withdrawal time, and elderly patients with larger waist circumference.

CONCLUSION

The intervention of AI plays a limited role in overall polyp detection, but increases detection of easily missed polyps; ChiCTR.org.cn number, ChiCTR1800015607.

Propensity score-matched analysis of endoscopic resection for recurrent colorectal neoplasms: A pilot study

BACKGROUND AND AIM

Local residual/recurrent colorectal lesions after endoscopic resection (ER) are difficult to treat with conventional ER. Underwater endoscopic mucosal resection (UEMR) and endoscopic submucosal dissection (ESD) are reportedly effective. We investigated the appropriate indications of ESD and UEMR for recurrent colorectal lesions.

METHODS

This single-center, retrospective, observational study was conducted at a tertiary cancer institute. Patients who underwent UEMR or ESD for residual/recurrent colorectal lesions after ER from October 2013 to February 2019 were enrolled. Propensity score matching was performed between the UEMR and ESD groups to compare the clinical characteristics, treatment, and outcomes.

RESULTS

In total, 30 UEMRs and 21 ESDs were performed. Median (range) diameter of the lesions was 8 mm (2-22 mm) in UEMR and 15 mm (2-58 mm) in ESD. Median procedure time in UEMR was significantly shorter than that of ESD (4 min [2-15 min] vs 70 min [17-193 min], P < 0.001). En bloc and complete resection rates of ESD were significantly higher than that of UEMR (73% vs 100%, 41% vs 81%, respectively). No adverse events occurred with UEMR, but there were two cases (10%) of delayed perforation with ESD. Neither group reported recurrence after treatment. Propensity score-matched cases showed significantly shorter procedure time and hospitalization period in UEMR than in ESD.

CONCLUSIONS

The outcomes of UEMR and ESD were comparable. UEMR could be a useful salvage therapy for small local residual/recurrent colorectal lesions after ER with shorter procedure time and hospitalization period.

Efficacy of Underwater Endoscopic Mucosal Resection for Nonpedunculated Colorectal Polyps: A Systematic Review and Meta-Analysis

Recently, underwater endoscopic mucosal resection (UEMR) without submucosal injection was introduced as a new replacement for conventional EMR (CEMR) and was reported to be useful for resecting large colonic polyps. Here, we aimed to assess the efficacy and safety of these two methods by a systematic review and meta-analysis. We comprehensively searched multiple databases until July 2021 to identify randomized controlled trials (RCTs) comparing UEMR with CEMR. The primary outcomes were the proportion of R0 resection and mean procedure time, and the secondary outcomes were the proportion of en bloc resection and all adverse events. Three reviewers independently searched for articles, extracted data, and assessed the risk of bias. We evaluated the certainty of evidence using the Grading of Recommendations, Assessment, Development, and Evaluation approach. This study was registered in www.protocols.io (Protocol Integer ID: 40849). We included six RCTs (1,374 polyps). We judged that a meta-analysis was not available, and the data were summarized narratively for the proportion of R0 resection. Regarding procedure time, UEMR likely resulted in a large reduction (mean difference = -64.3 seconds; 95% confidence interval (CI) = -122.5 to -6.0 seconds; I2 = 86%; moderate certainty of evidence). UEMR likely resulted in a large increase in en bloc resection (odds ratio = 1.85; 95% CI = 1.15 to 2.98; I2 = 60%; moderate certainty of evidence). Percentages of adverse events were 0-17% with CEMR and 0-16% with UEMR. In summary, UEMR might have higher efficacy than CEMR in the endoscopic resection of nonpedunculated colorectal polyps, with likely a large reduction in procedure time.

Risk of metachronous neoplastic lesions during post-polypectomy surveillance in individuals with advanced colorectal neoplasia at initial screening colonoscopy

BACKGROUND AND AIM

The evidence of associations between some types of advanced colorectal neoplasia (ACN) at baseline and the risk of metachronous neoplasia is inconsistent. This study aimed to elucidate the incidence of metachronous neoplasia during post-polypectomy surveillance in individuals with ACN at baseline and examine the risk factors for its high incidence.

METHODS

Data from individuals who underwent endoscopic resection for ACN and received surveillance colonoscopy were analyzed. Data from individuals with no neoplastic lesions at baseline were used as reference. The incidence of metachronous ACN and clinically significant neoplasia (ACN and nonadvanced adenomas sized ≥ 5 mm) were evaluated. Risk factors for the higher incidence of these lesions were examined in individuals with ACN at baseline.

RESULTS

During the median follow-up period of 61.8 months, metachronous ACN and nonadvanced adenomas sized ≥ 5 mm were detected in 9.6% and 32.4% of individuals with ACN at baseline (n = 136), respectively. The cumulative incidence of metachronous ACN and clinically significant neoplasia in individuals with ACN at baseline (3-year incidence: 5.5% and 16.9%, respectively) was higher than that in individuals with no neoplastic lesions at baseline (P < 0.01 for both). The presence of advanced histology at baseline, ≥ 5 neoplastic lesions at baseline, and family history of colorectal cancer were identified as risk factors for the higher incidence of clinically significant neoplasia.

CONCLUSIONS

The relatively high incidence of metachronous neoplasia in individuals with ACN at baseline was confirmed; careful surveillance is required for these individuals, particularly in those with the risk factors.

Clinical Features and Genomic Characterization of Post-Colonoscopy Colorectal Cancer

INTRODUCTION

Some colorectal cancers (CRCs) may be missed during colonoscopies. We aimed to determine the clinicopathological, biological, and genomic characteristics of post-colonoscopy CRCs (PCCRCs).

METHODS

Of the 1,619 consecutive patients with 1,765 CRCs detected between 2008 and 2016, 63 patients with 67 PCCRCs, when colonoscopies were performed 6-60 months before diagnosis, were recruited. After excluding patients with inflammatory bowel disease, familial polyposis syndrome, CRCs that developed from diminutive adenomatous polyps, and recurrent CRCs after endoscopic resection, 32 patients with 34 PCCRCs were enrolled. The lesions' clinicopathological features, mismatch repair proteins (MMRs), and genomic alterations were investigated.

RESULTS

The overall PCCRC-5y rate, rate of intramucosal (Tis) lesions, and rate of T1 or more deeply invasive cancers were 3.7% (66/1,764), 3.9% (32/820), and 3.6% (34/944), respectively. Thirty-three patients' MMRs were investigated; 7 (21%) exhibited deficient MMRs (dMMRs), comprising 4 with T2 or more deeply invasive cancers and 5 whose lesions were in the proximal colon. Twenty-three tumors' genomic mutations were investigated; PIK3CA had mutated in 5 of 6 T2 or more deeply invasive cancers, of which, 4 were located in the proximal colon. Two patients with dMMRs and BRAF mutations had poor prognoses. Sixty-one percent (17/28) of the macroscopic type 0 lesions were superficial. All superficial Tis and T1 PCCRCs were detected <24 months after the negative colonoscopies. They were distributed throughout the colon and rectum.

DISCUSSION

PCCRCs may be invasive cancers in the proximal colon that exhibit dMMRs and/or PIK3CA mutations or missed early CRCs especially superficial lesions.

Management of Less Than 10-mm-Sized Pedunculated (Ip) Polyps with Thin Stalk: Hot Snare Polypectomy Versus Cold Snare Polypectomy

BACKGROUND

Although the use of cold snare polypectomy (CSP) has spread rapidly, its safety for pedunculated (Ip) polyps remains controversial. In particular, the outcomes of hot snare polypectomy (HSP) and CSP for Ip polyps have not been previously compared.

AIMS

This study evaluated whether the rate of delayed postpolypectomy bleeding (DPPB) after CSP for Ip polyps was higher than that after HSP for Ip polyps and compared other outcomes (the rates of immediate bleeding and pathological margins) between the HSP and CSP procedures.

METHODS

A total of 5905 colorectal polyps in 4920 patients were resected at Omori Red Cross Hospital between October 2012 and June 2019. The polyps were divided into two groups: the HSP group (86 polyps, 64 patients) and the CSP group (102 polyps, 87 patients). The primary outcome measure was the incidence of DPPB. The secondary outcome measures were the incidences of immediate bleeding during the procedure and pathological margins of the resected specimen.

RESULTS

The rate of immediate bleeding during CSP was significantly higher than that for the HSP group [38.2% (39/102) versus 3.5% (3/86); p < 0.001]. However, the rate of DPPB was significantly higher in the HSP group than in the CSP group [4.7% (4/86) versus 0% (0/102); p < 0.001]. The rate of DPPB after CSP was 0%.

CONCLUSIONS

This is the first study to compare the outcomes of HSP and CSP for Ip polyps. CSP is safer than HSP for Ip polyps measuring < 10 mm in diameter.

Platelet-to-lymphocyte ratio and C-reactive protein as markers for colorectal polyp histological type

Background

The platelet-to-lymphocyte ratio (PLR) and C-reactive protein (CRP) level are markers that have been reported to predict the histological type of various tumors, and here, we evaluated their utility in predicting colorectal polyp histological types.

Methods

We retrospectively reviewed 172 patients with colorectal polyps who underwent endoscopic polypectomy. The associations between histological type and clinicopathologic parameters were assessed by multivariate analysis.

Results

The optimal PLR and CRP cut-off values were 113.32 and 0.39, respectively. The PLR (P = 0.002) and CRP (P = 0.009) values were associated with the histological type according to the univariate analysis, whereas low PLR (P ≤ 0.001) and CRP (P = 0.017) values were independent risk factors in the multivariate analysis together with maximum tumor diameter (P ≤ 0.001) and tumor number (P = 0.0014).

Conclusions

Preoperative PLR and CRP are correlated with the colorectal polyp histological type.

Accurate measurement of colorectal polyps using computer-aided analysis

INTRODUCTION

As we know, the majority of colorectal cancers are thought to evolve from colorectal adenomas. In this study, we explored the use of Computer-aided diagnosis (CAD) in the detection of colorectal polyps and the estimation of their sizes, which is important for the diagnosis and management of colorectal cancer.

MATERIALS AND METHODS

As the distance between colonoscopy and lesion increases, magnification tends to decrease. Therefore, the size of colorectal polyps can be calculated by taking into account the captured image and the shooting distance. In this study, the fitting curve of the magnification of electronic colonoscopy was obtained by simulating intestinal tract and polyps in vitro. Then, the distance was artificially controlled in the endoscopic operation, and the image was taken at a preset distance. The CAD system was then trained on the overall shape of colorectal polyps. Image segmentation was employed to accurately identify colorectal polyps. Finally, on the basis of the magnification factor, the real value of polyps was predicted from the shooting distance and the segmentation image size.

RESULTS

The CAD system can automatically calculate the range of colorectal polyps and calculate the true size of the colorectal polyps according to the magnification of the corresponding distance.

CONCLUSIONS

In this study, we developed a method of accurately estimating the size of colorectal polyps. This approach is compatible with many devices, which would expand its range of applications. This method has the potential for application in other areas of clinical diagnosis.

Clinical validation of the SIMPLE classification for optical diagnosis of colorectal polyps

Background and study aims  A novel endoscopic optical diagnosis classification system (SIMPLE) has recently been developed. This study aimed to evaluate the SIMPLE classification in a clinical cohort. Patients and methods  All diminutive and small colorectal polyps found in a cohort of individuals undergoing screening, diagnostic, or surveillance colonoscopies underwent optical diagnosis using image-enhanced endoscopy (IEE) and the SIMPLE classification. The primary outcome was the agreement of surveillance intervals determined by optical diagnosis compared with pathology-based results for diminutive polyps. Secondary outcomes included the negative predictive value (NPV) for rectosigmoid adenomas, the percentage of pathology exams avoided, and the percentage of immediate surveillance interval recommendations. Analysis of optical diagnosis for polyps ≤ 10 mm was also performed. Results  399 patients (median age 62.6 years; 55.6 % female) were enrolled. For patients with at least one polyp ≤ 5 mm undergoing optical diagnosis, agreement with pathology-based surveillance intervals was 93.5 % (95 % confidence interval [CI] 91.4-95.6). The NPV for rectosigmoid adenomas was 86.7 % (95 %CI 77.5-93.2). When using optical diagnosis, pathology analysis could be avoided in 61.5 % (95 %CI 56.9-66.2) of diminutive polyps, and post-colonoscopy surveillance intervals could be given immediately to 70.9 % (95 %CI 66.5-75.4) of patients. For patients with at least one ≤ 10 mm polyp, agreement with pathology-based surveillance intervals was 92.7 % (95 %CI 89.7-95.1). NPV for rectosigmoid adenomas ≤ 10 mm was 85.1 % (95 %CI CI 76.3-91.6). Conclusions  IEE with the SIMPLE classification achieved the quality benchmark for the resect and discard strategy; however, the NPV for rectosigmoid polyps requires improvement.

Salvage endoscopic submucosal dissection for local residual/recurrent colorectal tumor after endoscopic resection: Large multicenter 10-year study

OBJECTIVES

For local residual/recurrent and endoscopic resection (ER) interrupted colorectal tumors, endoscopic retreatment is often difficult due to severe submucosal fibrosis. Endoscopic submucosal dissection (ESD) can achieve en bloc resection, even for tumors with severe submucosal fibrosis, although it is a risk factor for incomplete resection and perforation. We aimed to determine the safety and efficacy of colorectal ESD for local residual/recurrent tumors including ER interrupted tumors from a large multicenter study.

METHODS

From January 2008 until December 2018, 3,937 colorectal tumors were resected by ESD at the Hiroshima GI Endoscopy Research Group. From this group, 81 local residual/recurrent tumors and 21 ER interrupted tumors were included. We analyzed ESD outcomes, particularly the difference between the early and late phases and re-recurrence after ESD for local residual/recurrent tumors.

RESULTS

For local residual/recurrent tumors, en bloc and R0 resection rates were 95% (77/81) and 90% (73/81), respectively. The intraoperative perforation rate was 6% (5/81), and one patient required surgery. The delayed perforation rate was 2% (2/81), and one patient required surgery. For ER interrupted tumors, both the en bloc and R0 resection rates were 86% (18/21), with no major adverse events. For local residual/recurrent and ER interrupted tumors, the intraoperative perforation rate was significantly lower in the late phase compared with the early phase. Following curative resection for local residual/recurrent tumors, no local re-recurrences occurred.

CONCLUSIONS

Colorectal ESD is an effective treatment for local residual/recurrent and ER interrupted tumors.

Effect of water exchange method on adenoma miss rate of patients undergoing selective polypectomy: A randomized controlled trial

BACKGROUND

Adenomas may be missed in up to 40% of screening colonoscopies. Although the water exchange (WE) method can improve ADR, as shown in several RCTs, it remains uncertain whether it can increase the detection of missing adenomas compared with standard air-insufflated (AI) colonoscopy.

METHODS

Patients aged 18-80 years who underwent selective polypectomy were randomly allocated to the WE or AI group. The primary endpoint was the adenoma miss rate (AMR), defined as the number of patients with one or more additional adenomas during the polypectomy procedure divided by the total number of patients in each group.

RESULTS

A total of 450 patients were enrolled, with 225 in each group. The overall AMRs were 45.8% (103/225) in the WE group and 35.6% (80/225) in the AI group (p = 0.035). More patients in the WE group had at least one missed adenoma in the proximal colon (38.2% vs 24.4%, p = 0.002). The adenoma-level miss rate was also higher in the WE group than in the AI group (35.1% vs 29.0%, p = 0.036). Subgroup analysis showed that patients in the WE group had more missed adenomas located in the proximal colon or with flat shapes.

CONCLUSIONS

This study confirmed that substantial adenomas were missed in patients undergoing selective polypectomy. The WE method significantly improved the detection of missed adenomas, especially those located in the proximal colon or with flat shapes. (ClnicalTrials.gov number: NCT02880748).

TOX Acts as a Tumor Suppressor by Inhibiting mTOR Signaling in Colorectal Cancer

The treatment and prognosis of advanced colorectal cancer (CRC) remain a challenging clinical research focus. Here, we describe a new CRC tumor suppressor and potential therapeutic target: thymocyte selection associated high mobility group box (TOX) protein. The expression of TOX was lower in CRC than para-CRC. With the increase of tumor stage, TOX expression decreased, indicating the presence of TOX relates to better overall survival (OS). TOX suppressed the mechanistic target of rapamycin kinase (mTOR) signaling to inhibit cell proliferation, migration, invasion, and change the epithelial-mesenchymal transition (EMT) process. In addition, TOX promoted apoptosis. As tumor mutation burden and tumor microenvironment play vital roles in the occurrence and development of tumors, we analyzed the TOX expression in the immune microenvironment of CRC. The high TOX expression was negatively correlated with TumorPurity. Moreover, it was positively related to ImmuneScore, StromalScore, microsatellite instability (MSI) status, and Consensus Molecular Subtypes (CMS) 3 typing. Based on gene set enrichment analysis (GSEA), the reduced expression of TOX activated mTOR. We found rapamycin, a mTOR inhibitor, partly inhibited cell proliferation, invasion, and migration in shTOX HCT116 cells. Lastly, TOX suppressed tumorigenesis and lung metastasis of CRC in vivo. Rapamycin alone or combined with PD1 inhibitor is more effective than PD1 inhibitor alone in a tumor model. Taken together, these findings highlight the tumor-suppressive role of TOX in CRC, especially in MSI CRC, and provide valuable information that rapamycin alone or combined with PD1 inhibitor has therapeutic potential in CRC.

Evidence-based clinical practice guidelines for management of colorectal polyps

BACKGROUND

The Japanese Society of Gastroenterology (JSGE) published ''Daicho Polyp Shinryo Guideline 2014'' in Japanese and a part of this guideline was published in English as "Evidence-based clinical practice guidelines for management of colorectal polyps" in the Journal of Gastroenterology in 2015. A revised version of the Japanese-language guideline was published in 2020, and here we introduce a part of the contents of revised version.

METHODS

The guideline committee discussed and drew up a series of clinical questions (CQs). Recommendation statements for the CQs were limited to items with multiple therapeutic options. Items with established conclusions that had 100% agreement with previous guidelines (background questions) and items with no (or old) evidence that are topics for future research (future research questions: FRQs) were given descriptions only. To address the CQs and FRQs, PubMed, ICHUSHI, and other sources were searched for relevant articles published in English from 1983 to October 2018 and articles published in Japanese from 1983 to November 2018. The Japan Medical Library Association was also commissioned to search for relevant materials. Manual searches were performed for questions with insufficient online references.

RESULTS

The professional committee created 18 CQs and statements concerning the current concept and diagnosis/treatment of various colorectal polyps, including their epidemiology, screening, pathophysiology, definition and classification, diagnosis, management, practical treatment, complications, and surveillance after treatment, and other colorectal lesions (submucosal tumors, nonneoplastic polyps, polyposis, hereditary tumors, ulcerative colitis-associated tumors/carcinomas).

CONCLUSIONS

After evaluation by the moderators, evidence-based clinical practice guidelines for management of colorectal polyps were proposed for 2020. This report addresses the therapeutic related CQs introduced when formulating these guidelines.

Risk stratification for advanced colorectal neoplasia based on the findings of the index and first surveillance colonoscopies

Risk stratification by index colonoscopy is well established for first surveillance endoscopy, but whether the previous two colonoscopies affect the subsequent advanced neoplasias has not been established. Therefore, the subsequent risk based on the findings of the index and first surveillance colonoscopies were investigated. This retrospective, cohort study was conducted in two clinics and included participants who had undergone two or more colonoscopies after index colonoscopy. High-risk was defined as advanced adenoma (≥ 1 cm, or tubulovillous or villous histology, or high-grade dysplasia). Based on the findings of the index and first surveillance colonoscopies, patients were classified into four categories: category A (both colonoscopy findings were normal), category B (no high-risk findings both times), category C (one time high-risk finding), and category D (high-risk findings both times). The incidence of subsequent advanced neoplasia was examined in each category. A total of 13,426 subjects were included and surveyed during the study periods. The subjects in category D had the highest risk of advanced neoplasia (27.4%, n = 32/117). The subjects in category A had the lowest risk (4.0%, n = 225/5,583). The hazard ratio for advanced neoplasia of category D compared to category A was 9.90 (95% Confidence interval 6.82-14.35, P<0.001). Classification based on the findings of index and first surveillance colonoscopies more effectively stratifies the risk of subsequent advanced neoplasia, resulting in more proper allocation of colonoscopy resources after two consecutive colonoscopies.

Comparative Study of Narrow-Band Imaging and i-scan for Predicting the Histology of Intermediate-to-Large Colorectal Polyps: A Prospective, Randomized Pilot Study

Background/Aims

To date, no reports have compared the diagnostic efficacy of narrow-band imaging (NBI) and i-scan for the histologic prediction of intermediate-to-large colorectal polyps. We aimed to compare the diagnostic accuracy of NBI and i-scan in predicting histology, and their inter-/intra-observer agreement.

Methods

We performed a prospective, randomized study that included 66 patients (NBI, n=33 vs. i-scan, n=33) with colorectal polyps (size >10 mm but <50 mm) who underwent colonoscopic resection. During the procedure, three endoscopists documented their prediction using the Japan NBI Expert Team (JNET) classification. Two months after study completion, the endoscopists reviewed still images and video clips for analysis.

Results

The overall diagnostic accuracies in the NBI and i-scan groups were 73.7% (73/99) and 75.8% (75/99), respectively, and there was no statistical significance between the two groups (p=0.744). The JNET classification as applied to NBI and i-scan showed substantial inter-observer agreement (NBI κ-value 0.612, p=0.001 vs. i-scan κ-value 0.662, p=0.002). Additionally, the κ-values of intra-observer agreement were in the range of 0.385–0.660 with NBI and 0.364–0.741 with i-scan.

Conclusions

NBI and i-scan have similar diagnostic accuracies for the histologic prediction of intermediate-to-large colorectal polyps. Furthermore, the inter-/intra-observer agreement was acceptable for both modalities when the JNET classification was applied.

The efficacy and safety of sulindac for colorectal polyps: A protocol for systematic review and meta-analysis

BACKGROUND

Sulindac has been used for treating colorectal polyps widely. However, the efficacy and safety of sulindac for colorectal polyps are unclear. This study aims to evaluate the efficacy and safety of sulindac for colorectal polyps.

METHODS

Randomized controlled trials of sulindac in the treatment of colorectal polyps will be searched in PubMed, EMbase, Cochrane Library, Web of Science, China National Knowledge Infrastructure (CNKI), WanFang, the Chongqing VIP Chinese Science, and Technology Periodical Database, and China biomedical literature database (CBM) from inception to August, 2020. And Baidu Scholar, Google Scholar, International Clinical Trials Registry Platform, and Chinese Clinical Trials Registry will be searched to obtain more relevant studies comprehensively. Two researchers will perform data extraction and risk of bias assessment independently. Statistical analysis will be conducted in RevMan 5.3.

RESULTS

This study will summarize the present evidence by exploring the efficacy and safety of sulindac in the treatment of colorectal polyps.

CONCLUSION

The findings of the study will provide helpful evidence for the efficacy and safety of sulindac in the treatment of colorectal polyps, facilitating clinical practice and further scientific studies.

ETHICS AND DISSEMINATION

The private information from individuals will not publish. This systematic review also will not involve endangering participant rights. Ethical approval is not required. The results may be published in a peer-reviewed journal or disseminated in relevant conferences.

OSF REGISTRATION NUMBER

DOI 10.17605/OSF.IO/N5GDH.

Cost-effectiveness analysis of colorectal cancer screening using colonoscopy, fecal immunochemical test, and risk score

BACKGROUND AND AIM

A risk-stratification score may be useful for colorectal cancer (CRC) screening, alongside screening colonoscopy (CS) and fecal immunochemical test (FIT). This study aimed to evaluate the effectiveness and cost-effectiveness of population-based CRC screening strategies using CS, FIT, and the Japanese CRC screening score.

METHODS

The effectiveness in quality-adjusted life years (QALYs), cost-effectiveness, and required number of CS procedures were evaluated for screening strategies with primary screening CS (strategy 1), FIT (strategy 2), and the risk score (strategy 3), using a simulation model analysis with two scenarios. In scenario 1, uptake rates for all tests were 60%. In scenario 2, uptake rates for FIT and a risk score were 40%, and those for screening CS and CS following a positive FIT or high risk score were 20% and 70%, respectively.

RESULTS

In scenario 1, strategy 1 gained the highest QALYs and required the highest cost. The incremental cost-effectiveness ratios per QALY gained for strategy 1 against the others were lower than 5 000 000 JPY. Strategy 1 required more than twice as many CS procedures as the other strategies. In scenario 2, strategy 3 had the highest QALYs and lowest cost, and strategy 1 had the lowest QALYs and highest cost.

CONCLUSIONS

Screening CS has the potential to be the most effective and cost-effective form of CRC screening, although it requires a large number of CS procedures. However, if non-invasive tests are preferred by recipients, other screening strategies, particularly those using the risk score, can be more effective and cost-effective.