Endoscopic Removal of Premalignant Lesions Reduces Long-Term Colorectal Cancer Risk: Results From the Japan Polyp Study.

BACKGROUND & AIMS: To date, no regional evidence of long-term colorectal cancer (CRC) risk reduction after endoscopic premalignant lesion removal has been established. We aimed to analyze this over a long-term follow-up evaluation. METHODS: This was a prospective cohort study of participants from the Japan Polyp Study conducted at 11 Japanese institutions. Participants underwent scheduled follow-up colonoscopies after a 2-round baseline colonoscopy process. The primary outcome was CRC incidence after randomization. The observed/expected ratio of CRC was calculated using data from the population-based Osaka Cancer Registry. Secondary outcomes were the incidence and characteristics of advanced neoplasia (AN). RESULTS: A total of 1895 participants were analyzed. The mean number of follow-up colonoscopies and the median follow-up period were 2.8 years (range, 1-15 y) and 6.1 years (range, 0.8-11.9 y; 11,559.5 person-years), respectively. Overall, 4 patients (all males) developed CRCs during the study period. The observed/expected ratios for CRC in all participants, males, and females, were as follows: 0.14 (86% reduction), 0.18, and 0, respectively, and 77 ANs were detected in 71 patients (6.1 per 1000 person-years). Of the 77 ANs detected, 31 lesions (40.3%) were laterally spreading tumors, nongranular type. Nonpolypoid colorectal neoplasms (NP-CRNs), including flat (<10 mm), depressed, and laterally spreading, accounted for 59.7% of all detected ANs. Furthermore, 2 of the 4 CRCs corresponded to T1 NP-CRNs. CONCLUSIONS: Endoscopic removal of premalignant lesions, including NP-CRNs, effectively reduced CRC risk. More than half of metachronous ANs removed by surveillance colonoscopy were NP-CRNs. The Japan Polyp Study: University Hospital Medical Information Network Clinical Trial Registry: University Hospital Medical Information Network Clinical Trial Registry, C000000058; cohort study: UMIN000040731.

[A Case of Penile Calciphylaxis in a Hemodialysis Patient].

In the present case of a 56-year-old male, hemodialysis was introduced from December 20XX-2 due to chronic renal failure caused by diabetic nephropathy. In February 20XX, a glans penis ulcer was observed. It gradually expanded. Angiography conducted in April revealed complete occlusion of the left internal pudendal artery and poor visualization of the bilateral penile arteries. Given the high risk of obstruction, endovascular treatment was not conducted. The glans penis ulcer continued to expand, and maintenance dialysis became difficult due to intractable pain. Opioids were introduced, but the pain could not be controlled. In May 20XX, the patient was referred to our department for surgical treatment, and partial penile resection was performed. The patient was diagnosed with penile calciphylaxis based on clinical findings and pathological diagnosis. After the surgery, the pain subsided considerably, and the patient is being followed on an out-patient basis.

Feasibility of endoscopic submucosal dissection for cecal tumors involving the ileocecal valve or appendiceal orifice.

BACKGROUND AND AIM: Endoscopic resection of the ileocecal valve lesions (ICVL) and peri-appendiceal orifice lesions (PAOL), is challenging. This study aimed to evaluate the feasibility of endoscopic submucosal dissection (ESD) for ICVLs and PAOLs compared with other cecal lesions (OCEL). METHODS: This was a multicenter, retrospective cohort study conducted at a cancer center hospital and two community hospitals. Non-pedunculated cecal lesions that were intended to be treated by ESD followed by at least one surveillance colonoscopy were included. The main outcome was curative resection defined as en-bloc resection and R0 resection without risk factors of metastases. The secondary outcome was co lon preservation. RESULTS: A total of 206 patients with 206 cecal lesions, including 37 ICVL, 27 PAOL, and 142 OCEL, who were to be treated with ESD were included in this study. Curative resection rates were 75.7% for ICVL, 70.4% for PAOL, and 77.5% for OCEL (P = 0.67). In the multivariate analysis of predictors of curative resection, tumor size (<40 mm) (odds ratio [OR] 2.40; 95% confidence intervals [CI], 1.14-5.04; P = 0.02) and a negative non-lifting sign (OR 6.12; 95% CI, 2.55-14.60; P < 0.01) were significant. Colon preservation was achieved for 91.9% of the ICVL, 92.6% of the PAOL, and 90.8% of the OCEL (P = 0.947). CONCLUSIONS: Based on curative resection and colon preservation rates, ESD was found to be feasible for ICVL and PAOL. Large tumor size (≥ 40 mm) and positive non-lifting signs were significant factors for non-curative resection.

Tip-in Endoscopic Mucosal Resection for 15- to 25-mm Colorectal Adenomas: A Single-Center, Randomized Controlled Trial (STAR Trial).

INTRODUCTION: One-piece endoscopic mucosal resection (EMR) for lesions >15 mm is still unsatisfactory, and attempted 1-piece EMR for lesions >25 mm can increase perforation risk. Therefore, modifications to ensure 1-piece EMR of 15- to 25-mm lesions would be beneficial. The aim of this study was to investigate whether Tip-in EMR, which anchors the snare tip within the submucosal layer, increases en bloc resection for 15- to 25-mm colorectal lesions compared with EMR. METHODS: In this prospective randomized controlled trial, patients with nonpolypoid colorectal neoplasms of 15-25 mm in size were recruited and randomly assigned in a 1:1 ratio to undergo Tip-in EMR or standard EMR, stratified by age, sex, tumor size category, and tumor location. The primary endpoint was the odds ratio of en bloc resection adjusted by location and size category. Adverse events and procedure time were also evaluated. RESULTS: We analyzed 41 lesions in the Tip-in EMR group and 41 lesions in the EMR group. En bloc resection was achieved in 37 (90.2%) patients undergoing Tip-in EMR and 30 (73.1%) who had EMR. The adjusted odds ratio of en bloc resection in Tip-in EMR vs EMR was 3.46 (95% confidence interval: 1.06-13.6, P = 0.040). The Tip-in EMR and EMR groups did not differ significantly in adverse event rates (0% vs 4.8%) or median procedure times (7 vs 5 minutes). DISCUSSION: In this single-center randomized controlled trial, we found that Tip-in EMR significantly improved the en bloc resection rate for nonpolypoid lesions 15-25 mm in size, with no increase in adverse events or procedure time.

Small-Dose Endoscopic Tattooing Using a Novel Needle for Localization Prior to Laparoscopic Surgery of Colorectal Cancer.

BACKGROUNDS: Endoscopic tattooing failure by deep mural injection or tattoo leakage-induced massive staining causes localization errors or decreased laparoscopic visualization. To overcome these, we developed a novel tattoo needle with comparatively shorter needle (length, 2.5 mm) and minimal-caliber catheter (volume, 0.3 mL). AIMS: The single-center, prospective observational study aimed to determine the efficacy and safety of a small-doze endoscopic tattooing prior to laparoscopic surgery for colorectal cancer, using the needle. METHODS: Patients with colorectal cancer indicated for laparoscopic surgery were recruited. With the novel needle, a single tattoo was created at the anterior wall close to the lesion. During laparoscopic surgery, surgeons assessed the tattoo visibility, tattoo leakage, and the disturbance of laparoscopic view by tattoo leakage. The primary endpoint was an accurate localization by visible tattoo. Secondary endpoints were adverse events related to tattooing, the need for intraoperative endoscopy, and tattoo leakage. RESULTS: A total of 383 tattoos in 358 patients were analyzed. Accurate tumor localization rate was 96.6% (95% confidence interval [CI]: 94.3-98.0%). No adverse events occurred. Intraoperative colonoscopy was performed in 7 (1.8%) patients with invisible tattoo. Tattoo leakage was found in 4.2% (95%CI: 2.6-6.7%), and leakage disturbed the laparoscopic view of the surgical plane in 0.7% (95%CI: 0.3-2.3%). CONCLUSIONS: Prior to laparoscopic surgery for colorectal cancer, our endoscopic tattooing with a standardized protocol using a novel needle is considered a simple, highly reliable localization technique with an extremely safe profile, which would be valuable to reduce physician's efforts and redundant medical resources. Trial registration number UMIN000021012. Date of registration: June 2016.

[A Case of Pelvic Lymph Node Recurrence Detected by PSMA PET/CT after Primary Proton Beam Radiotherapy for Prostate Cancer].

The patient is a 72-year-old man who was referred to our hospital with an elevated prostate specific antigen (PSA) level. He was diagnosed with prostate cancer (cT2aN0M0) at the age of 62 years. He had undergone radical proton beam radiotherapy. The PSA level decreased to a nadir of 0.217 ng/ml after 5 years, gradually increasing thereafter to 1.595 ng/ml during the next 5 years. Although magnetic resonance imaging of the prostate showed an abnormal signal area in the prostate, repeated biopsies of the prostate revealed no malignant findings. Contrast-enhanced abdominal computed tomography (CT), bone scintigraphy and fluoro-2-deoxy-D-glucose positron emission tomography (FDG-PET)/CT did not detect any abnormalities in the prostate or metastatic lesions. ¹8F-prostate specific membrane antigen (PSMA)-PET/CT showed no accumulation in the prostate, but some accumulation in a left obturator lymph node. Open pelvic lymph node dissection was performed, and pathological examination confirmed lymph node metastasis from the prostate cancer. The PSA level decreased from 2.482 ng/ml preoperatively to 0.391 ng/ml at 3 months postoperatively. PSMA-PET/CT might be useful for early localization of recurrent lesions in biochemical recurrence after radical treatment for prostate cancer.

Randomised comparison of postpolypectomy surveillance intervals following a two-round baseline colonoscopy: the Japan Polyp Study Workgroup.

OBJECTIVE: To assess whether follow-up colonoscopy after polypectomy at 3 years only, or at 1 and 3 years would effectively detect advanced neoplasia (AN), including nonpolypoid colorectal neoplasms (NP-CRNs). DESIGN: A prospective multicentre randomised controlled trial was conducted in 11 Japanese institutions. The enrolled participants underwent a two-round baseline colonoscopy (interval: 1 year) to remove all neoplastic lesions. Subsequently, they were randomly assigned to undergo follow-up colonoscopy at 1 and 3 years (2-examination group) or at 3 years only (1-examination group). The incidence of AN, defined as lesions with low-grade dysplasia ≥10 mm, high-grade dysplasia or invasive cancer, at follow-up colonoscopy was evaluated. RESULTS: A total of 3926 patients were enrolled in this study. The mean age was 57.3 (range: 40-69) years, and 2440 (62%) were male. Of these, 2166 patients were assigned to two groups (2-examination: 1087, 1-examination: 1079). Overall, we detected 29 AN in 28 patients at follow-up colonoscopy in both groups. On per-protocol analysis (701 in 2-examination vs 763 in 1-examination group), the incidence of AN was similar between the two groups (1.7% vs 2.1%, p=0.599). The results of the non-inferiority test were significant (p=0.017 in per-protocol, p=0.001 in intention-to-treat analysis). NP-CRNs composed of dominantly of the detected AN (62%, 18/29), and most of them were classified into laterally spreading tumour non-granular type (83%, 15/18). CONCLUSION: After a two-round baseline colonoscopy, follow-up colonoscopy at 3 years detected AN, including NP-CRNs, as effectively as follow-up colonoscopies performed after 1 and 3 years.

A risk-prediction model for en bloc resection failure or perforation during endoscopic submucosal dissection of colorectal neoplasms.

OBJECTIVES: Technical difficulties in colorectal endoscopic submucosal dissections (ESD) result in en bloc resection failure or perforation. This study aimed to develop and validate a risk score for predicting en bloc resection failure or perforation in ESD of colorectal neoplasms. METHODS: This single-center observational study included 1133 colorectal neoplasms treated with ESD in a Japanese tertiary cancer center. With a derivation set (n = 716), we performed multiple logistic regression to identify significant risk factors for en bloc resection failure or perforation. Based on odds ratios, we developed a risk score, ranging from 0 to 10: 0-1 'low risk' (LR); 2-4 'moderate risk' (MR); and 5-10 'high risk' (HR). An independent validation set comprised prospectively enrolled subjects (n = 417) that underwent ESDs from January 2014 to August 2016. The performance of the risk score for predicting en bloc resection failure or perforation for each risk tier was evaluated. RESULTS: The baseline incidences of en bloc resection failure or perforation were 14.5% and 5.5% in the derivation and validation sets, respectively. We identified the following significant risk factors: endoscopist experience, tumor location, morphology, scope operability, underlying fold, and fold convergence. In the validation set, the incidences of en bloc resection failure or perforation were 0% in the LR tier (n = 62; 14.8%), 2.3% in the MR tier (n = 293; 70.4%), and 25.8% in the HR tier (n = 62; 14.8%) (P < 0.001, Cochran-Armitage trend test). CONCLUSIONS: A risk scoring system, which was developed and prospectively validated, can successfully estimate the incidence of en bloc resection failure or perforation.

Magnified endoscopy with narrow-band imaging for the differential diagnosis of superficial non-ampullary duodenal epithelial tumors.

BACKGROUND AND AIM: Differentiation of low-grade adenoma (Vienna category 3, C3) and high-grade adenoma/carcinoma (C4/5) among superficial non-ampullary duodenal epithelial tumors (SNADETs) using magnified endoscopy with narrow-band imaging (MNBI) is not established. The aim of this study is to clarify the diagnostic ability of MNBI to differentiate between C3 and C4/5 among SNADETs. METHODS: A total of 585 MNBI images taken from 156 SNADETs were evaluated in a test and validation phase. In the test phase, MNBI patterns were extracted based on the combination of surface structure and vasculature. Comparison between MNBI patterns and histology was performed to establish diagnostic criteria to differentiate between C3 and C4/5. In the validation phase, the accuracy and interobserver agreement of the diagnostic criteria were assessed. RESULTS: Four MNBI patterns (network, disappeared, white opaque substance and intrastructural vessels) with distinctive histological features were selected. The median number of MNBI patterns observed among C3 and C4/5 differed with significance (1 vs 2, p < .01). The pattern of disappeared was suggestive of C4/5. Diagnosis of C4/5 by using the criteria of 2 or more MNBI patterns or presence of disappeared pattern revealed a sensitivity of 76%, specificity of 63% and accuracy of 72%. Interobserver agreement of recognizing MNBI patterns was moderate (kappa 0.59). CONCLUSION: Diagnosis based on MNBI patterns is useful to differentiate between C3 and C4/5 lesions among SNADETs.

Endoscopic prediction of advanced histology in diminutive and small colorectal polyps.

BACKGROUND AND AIM: Most polyps detected during colonoscopies are diminutive or small, and they rarely have advanced histology. Real-time prediction of advanced histology would help clinicians to assess the need for pathological evaluation. Here, we investigated endoscopic predictors of advanced histology in diminutive and small polyps. METHODS: Consecutive patients with adenomatous polyps (<10 mm) removed endoscopically from January 2013 to December 2014 at a single tertiary cancer center were eligible for inclusion. Two endoscopists reviewed all endoscopic images to identify significant findings associated with advanced histology using multivariate models. The sensitivity, specificity, and negative predictive value of the identified endoscopic predictors for advanced histology were calculated. RESULTS: Of 6170 polyps (4746 diminutive) removed from 2611 patients, 320 (5.2%) showed advanced histology, including five submucosal invasive cancers. In multivariate analysis, advanced histology was significantly associated with the following: loss of lobulation (odds ratio [OR] 61.7; 95% confidence interval [95% CI]: 19.1-199.0); heterogeneity in mucosal patterns (OR 29.0; 95% CI: 14.6-57.3); non-polypoid growth (OR 15.7; 95% CI: 4.4-55.5); white spots (OR 13.5; 95% CI: 7.8-23.5); and surface redness (OR 6.6; 95% CI: 3.0-14.5); and irregular capillary pattern (OR 4.8; 95% CI: 2.5-9.1). These significant predictors successfully predicted all submucosal invasive cancers as advanced histology. The sensitivity, specificity, and negative predictive values were 37.2%, 97.8%, and 96.6%. CONCLUSIONS: We identified six endoscopic predictors for advanced histology in diminutive or small colon polyps. Diminutive and small polyps lacking these predictors would not be considered to have advanced histology.

Treatment strategy for local recurrences after endoscopic resection of a colorectal neoplasm.

BACKGROUND AND AIM: Endoscopic salvage treatment for recurrent or residual neoplasms is sometimes technically challenging, and information in choice of treatment methods is lacking. This study aimed to clarify the appropriate treatment strategy for local recurrence after endoscopic resection (ER). METHODS: Seventy-four patients with 74 lesions who received endoscopic treatment for local recurrence after ER for colorectal epithelial neoplasms between January 2010 and December 2016 were enrolled. Patients with hyperplastic polyp, sessile-serrated adenoma/polyp, and submucosal invasive cancer in their initial ER were excluded. Treatment methods, treatment outcomes, and recurrence rate were evaluated for each recurrence based on the preoperative endoscopic diagnosis (adenomatous or cancerous). RESULTS: Forty-nine of the 74 patients diagnosed with adenomatous recurrence were treated using cold polypectomy, endoscopic mucosal resection (EMR), and endoscopic submucosal dissection (ESD) in 15, 26, and 8 patients, respectively. Cold polypectomy was applied only to diminutive lesions. EMR and ESD en bloc resection rates were 53.8 and 100%, respectively (p = 0.030). Two patients (7.7%) in the EMR group developed local recurrence, but an additional ER achieved complete resection. Meanwhile, the remaining 25 patients diagnosed with cancerous recurrence were treated via EMR and ESD for 7 and 18 patients, respectively. EMR and ESD en bloc resection rates were 28.6 and 83.3%, respectively (p = 0.017). Three patients (42.9%) in the EMR group developed recurrence. CONCLUSIONS: Selecting appropriate treatment methods for adenomatous recurrence could be decided based on estimated pathology and lesion size. ESD was effective for cancerous recurrence to achieve complete disease control.

Hybrid closed wedge high tibial osteotomy improves patellofemoral joint congruity compared with open wedge high tibial osteotomy.

PURPOSE: To evaluate clinical outcomes and radiographic changes in patellofemoral (PF) joint congruity between open wedge high tibial osteotomy (OWHTO) and hybrid closed wedge HTO (HCWHTO). METHODS: From 2011 to 2013, 36 knees in 31 patients who underwent OWHTO and 21 knees in 17 patients who underwent HCWHTO were evaluated in this retrospective study with a minimum 5-year follow-up. Radiological outcomes including hip-knee-ankle angle (HKA), femoral patellar height index (FPHI), preoperative PF osteoarthritis (OA) grade, medial and lateral joint spaces of the PF joint, and congruence angle were measured. Clinical parameters including the Knee injury and Osteoarthritis Outcome Score (KOOS) and the Oxford Knee Score (OKS) were also evaluated. Preoperative and final follow-up values for each procedure were compared in outcome analyses. RESULTS: Mean preoperative HKA and the degree of PF-OA were significantly more severe for patients treated with HCWHTO compared with those treated with OWHTO (p = 0.001, p = 0.0001). Mean postoperative FPHI was significantly decreased with proximalization of the patella in HCWHTO (p = 0.01) but showed no significant change in OWHTO (n.s.). Regarding PF joint congruity after HCWHTO, lateral joint space and congruence angle were significantly improved (p = 0.0001, p = 0.005), while medial joint space was not significantly changed (n.s.). After OWHTO, congruence angle showed no significant difference (n.s.), but medial and lateral joint spaces were significantly decreased (p = 0.0001, p = 0.018). There were no significant differences in KOOS and OKS between the groups (n.s., n.s.). CONCLUSIONS: Although degrees of varus knee and PF-OA were more severe in HCWHTO than those in OWHTO, HCWHTO led to improved PF joint congruity, and its mid-term clinical outcomes were equivalent to those of OWHTO. Therefore, in patients with varus knee combined with PF-OA preoperatively, HCWHTO is a more effective treatment than OWHTO. LEVEL OF EVIDENCE: Therapeutic level III.

Can the Ki-67 Labeling Index in Biopsy Specimens Predict the World Health Organization Grade of Rectal Neuroendocrine Tumors?

BACKGROUND: Being grade 2 is a known risk factor for metastasis in rectal neuroendocrine tumors (R-NETs). We aimed to identify the efficacy of the Ki-67 labeling index (LI) in endoscopic biopsy specimens to predict the World Health Organization (WHO) grade of R-NETs. METHODS: A total of 59 patients with 60 R-NETs (43 WHO grade 1 and 17 WHO grade 2), treated between October 2002 and December 2014, were retrospectively evaluated. The patients included in the study underwent biopsies followed by endoscopic submucosal resection with a ligation device, trans-anal full-thickness surgical resection, or radical surgery with lymph node dissection. The Ki-67 LI in the biopsy and resected specimens were compared between the 2 tumor grade groups, and the diagnostic sensitivity, specificity, and positive and negative predictive values for the detection of WHO grade 2 tumors were evaluated. RESULTS: The sensitivity, specificity, and positive and negative predictive values of the Ki-67 LI in biopsy specimens for predicting grade 2 tumors were 53% (9 of 17), 95% (41 of 43), 100% (9 of 9), and 87% (41 of 47), respectively. Pearson's rank correlation coefficient between the Ki-67 LI in the biopsy and resected specimens was 0.92. CONCLUSIONS: The Ki-67 LI of the biopsy specimen is useful for determining the appropriate treatment for R-NETs.

Risk factors of post-endoscopic submucosal dissection electrocoagulation syndrome for colorectal neoplasm.

BACKGROUND AND AIM: Colorectal endoscopic submucosal dissection (ESD) is used for the treatment of large colorectal superficial neoplasms. However, there have been no large studies on electrocoagulation syndrome developing after colorectal ESD. The aim of this study was to clarify the incidence and clinical risk factors of post-ESD electrocoagulation syndrome (PECS). METHODS: A total of 692 patients (median age: 70 years; 395 men) with 692 lesions, who underwent colorectal ESD at a tertiary cancer center between July 2010 and December 2015, were eligible. PECS was clinically diagnosed based on the presence of localized abdominal tenderness matching the ESD enforcement site and fever (> 37.5 °C) or an inflammatory response (C-reactive protein level > 0.5 mg/dL or leukocytosis > 10 000 cells/µL), without obvious findings of perforation, which developed at > 6 h post-ESD. Outcomes of the procedure, the incidence of PECS, and risk factors associated with PECS were assessed. RESULTS: The incidence of PECS was 4.8% (33 patients), and all patients improved by conservative treatment. On multivariate analysis, the female sex (odds ratio [OR] 2.6; 95% confidence interval [95% CI]: 1.2-5.7), tumor location at the cecum (OR 14.5; 95% CI: 3.7-53.7 vs rectum), and the presence of submucosal fibrosis (OR 2.8; 95% CI: 1.1-7.5) were found to be independent risk factors of PECS. CONCLUSIONS: This study identified the risk factors for PECS. Patients with high-risk factors of PECS require careful management after colorectal ESD.

Validation study for development of the Japan NBI Expert Team classification of colorectal lesions.

BACKGROUND AND AIM: The Japan narrow-band imaging (NBI) Expert Team (JNET) was organized to unify four previous magnifying NBI classifications (the Sano, Hiroshima, Showa, and Jikei classifications). The JNET working group created criteria (referred to as the NBI scale) for evaluation of vessel pattern (VP) and surface pattern (SP). We conducted a multicenter validation study of the NBI scale to develop the JNET classification of colorectal lesions. METHODS: Twenty-five expert JNET colonoscopists read 100 still NBI images with and without magnification on the web to evaluate the NBI findings and necessity of the each criterion for the final diagnosis. RESULTS: Surface pattern in magnifying NBI images was necessary for diagnosis of polyps in more than 60% of cases, whereas VP was required in around 90%. Univariate/multivariate analysis of candidate findings in the NBI scale identified three for type 2B (variable caliber of vessels, irregular distribution of vessels, and irregular or obscure surface pattern), and three for type 3 (loose vessel area, interruption of thick vessel, and amorphous areas of surface pattern). Evaluation of the diagnostic performance for these three findings in combination showed that the sensitivity for types 2B and 3 was highest (44.9% and 54.7%, respectively), and that the specificity for type 3 was acceptable (97.4%) when any one of the three findings was evident. We found that the macroscopic type (polypoid or non-polypoid) had a minor influence on the key diagnostic performance for types 2B and 3. CONCLUSION: Based on the present data, we reached a consensus for developing the JNET classification.

Can positron emission tomography detect colorectal adenomas and cancers?

BACKGROUND AND AIM: Fluorine-18 2-fluoro-2-deoxy-d-glucose positron emission tomography (PET) is effective and less invasive than other modalities used to diagnose tumors, including colorectal cancer (CRC). However, the detectability of adenomas and CRCs, especially in the early stages, is unclear. METHODS: We evaluated the records of 2323 consecutive eligible patients who underwent both a total colonoscopy (TCS) and PET between October 2002 and September 2012 at a tertiary cancer center. The PET findings were verified by TCS performed independently within 1 year. Target lesions were defined as CRCs and adenomas that were 6 mm or larger in size. RESULTS: Total colonoscopy detected 532 target lesions ≥ 6 mm in size: 56 T2-T4 CRCs, 39 T1 CRCs, 223 advanced adenomas, and 214 low-grade adenomas. Of the 532 lesions, 216 (40.6%) were PET positive. Of the 369 cases with positive uptakes, PET detected target lesions in the matched segments for 58.5% (216/369). Sensitivity of PET to T2-T4 CRCs, T1 CRCs, advanced adenomas, and low-grade adenomas was 92.9%, 79.5%, 50.7%, and 9.3%, respectively. PET could detect 76.5% (13/17) of T1 CRCs whose size is 10 to 19 mm and 85.0% (17/20) of T1 CRCs equal or larger than 20 mm. The multivariate analysis excluding T2-T4 CRCs showed malignant histology, larger size, protruded lesions, villous histology, and lesions in distal colon were significant factors. CONCLUSIONS: Sensitivity of PET for detecting T2-T4 and even T1 cancers are promising. However, sensitivity of PET to adenomas, even advanced adenomas, is limited.

Endoscopic submucosal dissection for large colorectal neoplasms.

BACKGROUND AND AIM: Endoscopic submucosal dissection (ESD) for colorectal neoplasms (CRN) of >50 mm is considered technically difficult. The ITknife nano™ was developed specifically for ESD of CRN and esophageal superficial neoplasms; however, only limited data are available regarding its use in this procedure. Here we assessed the safety and efficacy of ESD using the ITknife nano™ for large CRN (>50 mm). METHODS: We carried out a retrospective study, including consecutive patients with CRN larger than 50 mm that were treated by ESD between September 2002 and August 2016 at our institution. To clarify features of the ITknife nano™ and to assess its safety and efficacy, we compared en bloc/curative resection rates, complications, and resection speed between ESD done using the Dual knife™ with and without the ITknife nano™. RESULTS: We analyzed a total of 177 ESD-treated large CRN (median tumor size, 61 mm). Among the 133 CRN treated by ESD using the ITknife nano™, en bloc and curative resection rates were 96.2% and 80.5%, respectively. Perforation occurred in eight cases (6.0%) and delayed bleeding in four cases (3.0%). All complications were endoscopically managed. Resection speed was significantly faster for ESD using the ITknife nano™ (25.3 mm2 /min) compared to using the Dual knife™ only (19.9 mm2 /min; P = 0.02). CONCLUSIONS: Use of the ITknife nano™ for ESD treatment of large CRN (>50 mm) is feasible and may contribute to reduced procedure times. Further controlled studies are needed to confirm these findings.

Preoperative indicators of failure of en bloc resection or perforation in colorectal endoscopic submucosal dissection: implications for lesion stratification by technical difficulties during stepwise training.

BACKGROUND AND AIMS: The technical difficulties inherent in endoscopic submucosal dissection (ESD) for colorectal neoplasms may result in the failure of en bloc resection or perforation. The aim of this retrospective study was to assess the predictors of en bloc resection failure or perforation by using preoperatively available factors. METHODS: Between September 2002 and March 2013, 716 colorectal ESDs in 673 consecutive patients were performed at a tertiary cancer center. Patient characteristics, tumor location, tumor type, colonoscopy-related factors, and endoscopist experience were assessed based on a prospectively recorded institutional ESD database. Logistic regression analysis was performed to identify predictors of failure of en bloc resection or perforations, with subgroup analyses of ESDs performed by endoscopists less experienced in colorectal ESD (<40 cases) and for colonic lesions only. RESULTS: On multivariate analysis, independent predictors of failure of en bloc resection or perforations were the presence of fold convergence (odds ratio [OR] 4.4; 95% confidence interval [95% CI], 1.9-9.9), protruding type (OR 3.6; 95% CI, 1.8-7.1), poor endoscope operability (OR 3.5; 95% CI, 1.8-6.9), right-sided colonic lesions (OR 3.0; 95% CI, 1.5-6.3 vs rectal lesions), left-sided colonic lesions (OR 3.2; 95% CI, 1.7-6.3, vs rectal lesions), the presence of an underlying semilunar fold (OR 2.1; 95% CI, 1.3-3.6), and a less-experienced endoscopist (OR 2.1; 95% CI, 1.3-3.6). Among less-experienced endoscopists, colonic lesions were independent predictors (right-sided colonic lesions 8.1; 95% CI, 2.9-25.1; left-sided colonic lesions 8.1; 95% CI, 2.5-28.3 vs rectal lesions). For colonic lesions, the presence of fold convergence (OR 3.7; 95% CI, 1.6-8.6), poor endoscope operability (OR 3.6; 95% CI, 1.8-7.2), a less-experienced endoscopist (OR 3.0; 95% CI, 1.7-1.8), and the presence of an underlying semilunar fold (OR 2.7; 95% CI, 1.5-4.7) were identified predictors. CONCLUSION: This study successfully identified predictors of en bloc resection failure or perforation. Understanding these indicators could help to accurately stratify lesions according to technical difficulty and to appropriately select endoscopists.

The Ki-67 labeling index and lymphatic/venous permeation predict the metastatic potential of rectal neuroendocrine tumors.

BACKGROUND: Endoscopic resection has been used to treat small rectal neuroendocrine tumors (NETs). However, the indication for additional surgery after endoscopic resection is unclear. The aim of this study was to identify risk factors for rectal NET metastasis and to determine the indication for additional surgery. METHODS: Fifty-five patients with a total of 57 rectal NETs, treated between October 2003 and January 2013, were retrospectively divided into metastatic (11 lesions) and non-metastatic (46 lesions) groups. Tumor size, central depression, invasion depth, lymphatic and venous permeation, mitotic activity, nuclear abnormality, Ki-67 labeling index, and World Health Organization grading classification (G1 or G2) were compared between the groups. Patients underwent endoscopic submucosal resection with a ligation device, transanal full-thickness surgical resection, or radical surgery. RESULTS: By univariate analysis, the odds ratios (OR) for a Ki-67 labeling index >3.0 %, positive lymphatic or venous permeation, World Health Organization grading classification G2, tumor size >10 mm, submucosal invasion >4000 µm, and central depression were 120 (P < 0.001), 67.6 (P < 0.001), 58.7 (P < 0.001), 9.8 (P = 0.0037), 6.8 (P = 0.012), and 5.7 (P = 0.018), respectively. Multivariate logistic regression analyses showed that vascular permeation (OR 111; P = 0.006) and a Ki-67 labeling index >3.0 % (OR 88; P = 0.012) were independent risk factors for metastasis. CONCLUSIONS: The Ki-67 labeling index and lymphatic/venous permeation were reliable predictors of rectal NET metastases.

Narrow-band imaging (NBI) magnifying endoscopic classification of colorectal tumors proposed by the Japan NBI Expert Team.

Many clinical studies on narrow-band imaging (NBI) magnifying endoscopy classifications advocated so far in Japan (Sano, Hiroshima, Showa, and Jikei classifications) have reported the usefulness of NBI magnifying endoscopy for qualitative and quantitative diagnosis of colorectal lesions. However, discussions at professional meetings have raised issues such as: (i) the presence of multiple terms for the same or similar findings; (ii) the necessity of including surface patterns in magnifying endoscopic classifications; and (iii) differences in the NBI findings in elevated and superficial lesions. To resolve these problems, the Japan NBI Expert Team (JNET) was constituted with the aim of establishing a universal NBI magnifying endoscopic classification for colorectal tumors (JNET classification) in 2011. Consensus was reached on this classification using the modified Delphi method, and this classification was proposed in June 2014. The JNET classification consists of four categories of vessel and surface pattern (i.e. Types 1, 2A, 2B, and 3). Types 1, 2A, 2B, and 3 are correlated with the histopathological findings of hyperplastic polyp/sessile serrated polyp (SSP), low-grade intramucosal neoplasia, high-grade intramucosal neoplasia/shallow submucosal invasive cancer, and deep submucosal invasive cancer, respectively.