Comparison of the efficacy and tolerability of elobixibat plus sodium picosulfate with magnesium citrate and split-dose 2-L polyethylene glycol with ascorbic acid for bowel preparation before outpatient colonoscopy: a study protocol for the multicentre, randomised, controlled E-PLUS trial.

BACKGROUND: Sodium picosulfate (SP)/magnesium citrate (MC) and polyethylene glycol (PEG) plus ascorbic acid are recommended by Western guidelines as laxative solutions for bowel preparation. Clinically, SP/MC has a slower post-dose defaecation response than PEG and is perceived as less cleansing; therefore, it is not currently used for major bowel cancer screening preparation. The standard formulation for bowel preparation is PEG; however, a large dose is required, and it has a distinctive flavour that is considered unpleasant. SP/MC requires a small dose and ensures fluid intake because it is administered in another beverage. Therefore, clinical trials have shown that SP/MC is superior to PEG in terms of acceptability. We aim to compare the novel bowel cleansing method (test group) comprising SP/MC with elobixibat hydrate and the standard bowel cleansing method comprising PEG plus ascorbic acid (standard group) for patients preparing for outpatient colonoscopy. METHODS: This phase III, multicentre, single-blind, noninferiority, randomised, controlled, trial has not yet been completed. Patients aged 40-69 years will be included as participants. Patients with a history of abdominal or pelvic surgery, constipation, inflammatory bowel disease, or severe organ dysfunction will be excluded. The target number of research participants is 540 (standard group, 270 cases; test group, 270 cases). The primary endpoint is the degree of bowel cleansing (Boston Bowel Preparation Scale [BBPS] score ≥ 6). The secondary endpoints are patient acceptability, adverse events, polyp/adenoma detection rate, number of polyps/adenomas detected, degree of bowel cleansing according to the BBPS (BBPS score ≥ 8), degree of bowel cleansing according to the Aronchik scale, and bowel cleansing time. DISCUSSION: This trial aims to develop a "patient-first" colon cleansing regimen without the risk of inadequate bowel preparation by using both elobixibat hydrate and SP/MC. TRIAL REGISTRATION: Japan Registry of Clinical Trials (jRCT; no. s041210067; 9 September 2021; https://jrct.niph.go.jp/ ), protocol version 1.5 (May 1, 2023).

An unusual cytological presentation of solid pseudopapillary neoplasm of the pancreas mimicking adenoid cystic carcinoma: a case report and literature review.

Endoscopic ultrasound-guided fine-needle aspiration has become the common procedure for the diagnosis of pancreatic mass, and cytological examination is usually the first approach. Solid pseudopapillary neoplasm (SPN) cytologically represents papillary structures of branching capillaries surrounded by discohesive neoplastic cells. However, it may present various degrees of tissue degeneration, causing diagnostic challenges. Here, we report a 21-year-old female who had a 2-cm-sized mass in the pancreas head. Cytological examination revealed clumps of small round/oval cells that represented microcystic configurations with mucus, mimicking adenoid cystic carcinoma or mucinous adenocarcinoma. Cercariform cells, nuclear grooves/folding, and cytoplasmic vacuoles were not observed. Histopathological examination revealed confluent small glandular structures containing acidic mucus. The tumor cells were positively stained for ß-catenin, CD10, and CD56, and negative for chromogranin A and E-cadherin, suggesting SPN, micropseudocystic variant. This variant has been scarcely described, but we should recognize it for accurate cytological triage of pancreatic tumors.

M2 tumor-associated macrophages promote tumor progression in non-small-cell lung cancer.

Tumor-associated macrophages (TAMs) are key components of the tumor microenvironment that can be polarized into different phenotypes, including tumor-inhibiting M1 macrophages and tumor-promoting M2 macrophages. To elucidate the biological and clinical significance of M2 TAMs in non-small-cell lung cancer (NSCLC), a comprehensive clinical assessment of the tissue distribution of M2 TAMs was performed. The tissue distribution of M2 TAMs was retrospectively analyzed using CD163 immunohistochemistry in 160 consecutive patients who underwent NSCLC resection. Tumor proliferation was evaluated via the Ki-67 proliferation index. The results revealed that the stromal density of M2 TAMs was significantly associated with the C-reactive protein (CRP) level (P=0.0250), the Ki-67 proliferation index (P=0.0090) and invasive size (P=0.0285). Furthermore, the stromal M2 TAM density was significantly associated with tumor differentiation (P=0.0018), lymph node metastasis (P=0.0347) and pathological stage (P=0.0412). The alveolar M2 TAM density was also significantly associated with the CRP level (P=0.0309), invasive size (P<0.0001), tumor differentiation (P=0.0192), tumor status (P=0.0108) and pathological stage (P=0.0110). By contrast, no association was observed between islet M2 TAM density and the aforementioned biological and clinical factors. In regards to prognosis, disease-free survival rate was significantly lower in patients with stromal M2 TAM-high tumors (P=0.0270) and in those with alveolar M2 TAM-high tumors (P=0.0283). Furthermore, the overall survival rate was also significantly lower in patients with stromal M2 TAM-high tumors (P=0.0162) and in those with alveolar M2 TAM-high tumors (P=0.0225). Therefore, during NSCLC progression, M2 TAMs may induce tumor cell aggressiveness and proliferation and increase metastatic potential, resulting in a poor prognosis in patients with NSCLC.

PD-L1 expression on tumor-infiltrating immune cells is highly associated with M2 TAM and aggressive malignant potential in patients with resected non-small cell lung cancer.

OBJECTIVES: PD-L1 expression on tumor cells (TCs) and tumor-infiltrating immune cells (ICs) plays important roles in regulating the antitumor T cell response. However, the mechanistic and clinical significance of the effect of PD-L1 on TCs versus ICs remains unclear. On the other hand, tumor-associated macrophages (TAMs), M2 macrophages in particular, can promote tumor progression. METHODS: We evaluated PD-L1 expression on TCs and ICs using Ventana SP263 assay and the stromal M2 TAM distribution using CD163 staining in 160 consecutive patients with resected non-small cell lung cancer (NSCLC). RESULTS: PD-L1 expression on TCs and ICs was significantly higher in stromal M2 TAM-high group than in stromal M2 TAM-low group (p < 0.001 and p < 0.001, respectively). Regarding the clinical significance of PD-L1, PD-L1 expression on TCs was significantly associated with histology (p = 0.001), tumor differentiation (p < 0.001) and nodal status (p = 0.029). Furthermore, PD-L1 expression on ICs was significantly associated with histology (p < 0.001), tumor differentiation (p < 0.001), tumor status (p = 0.024), nodal status (p = 0.016), and pathologic stage (p = 0.004). The disease-free survival rate was significantly lower in patients with PD-L1-positive TC than in those with PD-L1-negative TC (p = 0.023), as well as in patients with PD-L1-positive IC than in those with PD-L1-negative IC (p < 0.001). Furthermore, the overall survival rate was significantly lower in patients with PD-L1-positive IC than in those with PD-L1-negative IC (p = 0.023). CONCLUSIONS: During tumor progression in NSCLC, the presence of M2 TAMs might affect PD-L1 expression both on TCs and ICs. In patients with NSCLC, PD-L1 expression both on TCs and ICs was associated with malignant behaviors, which was more in case of ICs.

Oil Gel-Based Phantom for Evaluating Quantitative Accuracy of Speed of Sound Measured in Ultrasound Computed Tomography.

To evaluate the quantitative accuracy of the measured speed of sound in ultrasound computed tomography for breast imaging, it is necessary to use a phantom with inclusions whose speed of sound is known. Accordingly, a phantom with known-speed-of-sound inclusions (e.g., containing water and saltwater solution) under the control of temperature was developed. In addition, an oil gel was used as the phantom material for mimicking wave refraction from fatty breast tissue to dense breast tissue. The oil gel was generated by adding SEBS (styrene-ethylene/butylene-styrene, 10% w/w) to paraffin oil. The oil gel-based phantom has a cylindrical shape and contains rod-shaped inclusions that can be filled with water or saltwater solution (3.5% w/w sodium chloride in water). When temperature increases, the speed of sound in the water increases, while that in the oil gel decreases; in particular, the speed of sound in the oil gel was higher than that in the water at temperatures <20.6°C, while the speed of sound in the oil gel was lower than that in the water at temperatures >20.6°C. It has been reported that the speed of sound in dense breast tissue is higher than that in water, while that in fatty breast tissue is lower than that in water. Ultrasound is refracted owing to the difference between the speed of sound in the breast tissue and that in the background water. By controlling the temperatures of the oil gel and water, the oil gel-based phantom simulates the refraction of an ultrasound wave from fatty breast tissue to dense breast tissue. For 43 d, the variation ranges of the speed of sound and attenuation in the oil gel in the reconstructed images were 0.7 m/s and 0.03 dB/MHz/cm, respectively. The concentration of the saltwater solution in the polyacrylamide gel-based phantom decreased from 1% (w/w) to 0.48% (w/w) after 24 h, while that in the oil-gel-based phantom was constant. In addition, magnetic resonance imaging of the oil gel-based phantom revealed that NiSO4 solution was stably contained in the phantom for 42 d. It is therefore concluded that the liquid cannot penetrate the oil gel. This oil gel-based phantom with such high temporal stability is suitable for multicenter distribution and may be used for standardization of data acquisition and image reconstruction across centers.

Incidence of Advanced Colorectal Neoplasia in Individuals With Untreated Diminutive Colorectal Adenomas Diagnosed by Magnifying Image-Enhanced Endoscopy.

OBJECTIVES: Because of the increasing number of detected diminutive colorectal adenomas, the "diagnose-and-do-not-resect" approach has recently attracted attention as an alternative to resection. We evaluated the cumulative incidence of advanced colorectal neoplasia (ACN) in individuals with untreated diminutive adenomas and compared this incidence in individuals without adenomas. METHODS: Data from 1,378 individuals who underwent first screening colonoscopy (CS) and at least one follow-up CS without polypectomy were analyzed. Patients with no adenomas or with only nonadvanced diminutive adenomas (<5 mm) diagnosed by magnifying image-enhanced endoscopy were scheduled to undergo a follow-up CS within 5 years after the initial CS without treatment. The participants were divided into 2 groups: those with untreated diminutive adenomas (group A) and those with no adenomas (group B). The cumulative incidence of ACN and the hazard ratio were assessed using Gray's test and the Fine and Gray model. RESULTS: During the median follow-up period of 60.9 months, 21 ACNs were detected. The 5-year cumulative incidences of ACN in group A (n = 361) and group B (n = 1,017) were 1.4% (95% confidence interval [CI]: 0.5-3.4) and 0.8% (95% CI: 0.3-1.7), respectively, without a statistically significant difference (P = 0.23). No ACNs developed from unresected adenomas. The smoking status was significantly associated with the incidence of ACN, and the hazard ratio for ACN in group A vs group B adjusted for smoking status was 1.43 (95% CI: 0.52-3.90; P = 0.48). DISCUSSION: The low 5-year cumulative incidence of ACN suggests the potential to adopt the "diagnose-and-do-not-resect" strategy as an alternative option for diminutive adenomas not requiring excessive surveillance.

Effects of vessel interruption sequence during thoracoscopic lobectomy for non-small cell lung cancer.

OBJECTIVE: This study aimed to determine if the vessel interruption sequence during thoracoscopic lobectomy affects disease recurrence. METHODS: We retrospectively analyzed 187 consecutive patients who underwent video-assisted thoracoscopic surgery lobectomy with curative intent for non-small cell lung cancer between January 2007 and December 2013. Their clinicopathological, operative, and postoperative data were compared. Patients with minimally invasive adenocarcinoma were excluded. RESULTS: A total of 104 patients underwent total venous interruption before interruption of any artery branch (V-first), while 83 patients underwent some artery interruption first (non-V-first). Clinicopathological characteristic distributions were similar between both groups except for the resected lobe. Seven of 104 patients in the V-first group and 15 of 83 patients in the non-V-first group experienced disease recurrences. Among the 187 patients who underwent thoracoscopic lobectomy, overall survival tended to be longer in the V-first group than in the non-V-first group (P = 0.080). Furthermore, disease-free survival was significantly longer in the V-first group than in the non-V-first group (P = 0.019), particularly in stage I patients (P = 0.047). Multivariate analysis showed that vessel interruption sequence was a significant prognostic factor for poor disease-free survival, after adjusting for pathological stage and histology (hazard ratio 2.127; 95% confidence interval 1.009-4.481). There was no significant difference in intraoperative blood loss between both groups. CONCLUSIONS: Interrupting the pulmonary vein first may be associated with improved disease-free survival in patients undergoing thoracoscopic lobectomy for non-small cell lung cancer.

Middle Mediastinal Thymoma.

Thymoma is a common neoplasm in the anterior mediastinum but rarely arises from the middle mediastinum. We report 3 patients with thymoma that arose from the middle mediastinum. Surgical resections were performed with dissection of the azygos vein, which led to safe separation of the tumors from mediastinal structures. Although rare, thymoma should be included in the differential diagnosis for middle mediastinal tumors.

Development and validation of a preoperative prognostic index independent of TNM stage in resected non-small cell lung cancer.

BACKGROUND: Previously reported prognostic tools for patients with resected non-small cell lung cancer (NSCLC) include factors found postoperatively, but not preoperatively. However, it would be important to predict patient prognosis before NSCLC resection. To suggest a novel preoperative prognostic tool, we evaluated the relationship of preoperative prognostic factors with the survival of patients with resected NSCLC. METHODS: We retrospectively reviewed the data of two independent cohorts of patients with completely resected NSCLC. To develop the prognostic index in one cohort, the overall survival (OS) was evaluated using the Cox proportional hazards model. We assessed the disease-free survival (DFS) and OS of three risk groups defined according to the prognostic index. Then, the prognostic index was validated in the other cohort. RESULTS: Seven independent risk factors for OS were selected: age ≥ 70 years, ever-smokers, vital capacity <80%, neutrophil-to-lymphocyte ratio ≥ 2.1, cytokeratin 19 fragment >normal limit, non-usual interstitial pneumonia (UIP) pattern, and UIP pattern. Three risk groups were defined: low-risk (36.9%), intermediate-risk (54.0%), and high-risk (9.1%). In the derivation cohort, the 5-year DFS rate was 77.8%, 58.8%, and 22.6% (P < 0.001), and the 5-year OS rate was 95.2%, 70.4%, and 28.9% (P < 0.001), respectively. Multivariate analyses showed that the prognostic index predicted DFS and OS, independent of pathological stage and tumor histology, in both derivation and validation cohorts. CONCLUSIONS: We developed and validated a simple preoperative prognostic index composed of seven variables, which may help clinicians predict prognosis before surgery in patients with NSCLC.

Emphysematous lungs do not affect visibility of virtual-assisted lung mapping.

BACKGROUND: It has recently been suggested that virtual-assisted lung mapping may enable safer and more reliable intraoperative navigation compared to conventional preoperative lung marking strategies. This study aimed to examine the relationship between emphysematous lungs and the intraoperative visibility of virtual-assisted lung mapping markings. METHODS: We retrospectively analyzed the data of 21 patients who underwent virtual-assisted lung mapping followed by lung resection between October 2013 and May 2015. The visibility of the intraoperative lung markings was graded. The degree of pulmonary emphysema was assessed by the percentage of low attenuation area on computed tomography. We elucidated the associations between the marking grade and other factors such as patient age or sex, pulmonary lobe mapped, marking operator, Brinkman index, and percentage of low attenuation area of the pulmonary lobe. RESULTS: In Spearman rank correlation analysis, there was no correlation between the Brinkman index and the percentage of low attenuation area (n = 26, r = -0.016, p = 0.937). In stepwise multivariate regression analysis, the marking grade correlated with the marking operator (p < 0.001) and the Brinkman index (p = 0.008), but not with patient age or sex, the pulmonary lobe mapped, or degree of pulmonary emphysema. CONCLUSION: The skill of the marking operator and the patient's smoking history had significant effects on the intraoperative visibility of markings made by virtual-assisted lung mapping, whereas emphysematous lungs did not affect the intraoperative visibility of lung markings.

Clinical impact of endoscopic clip closure of perforations during endoscopic submucosal dissection for colorectal tumors.

BACKGROUND AND AIMS: Despite advances in endoscopic submucosal dissection (ESD), perforation can still occur. The purpose of this study is to determine the clinical course and effectiveness of endoscopic closure in addition to the clinicopathologic features related to perforation. METHODS: A total of 935 lesions in 900 consecutive patients between February 1998 and February 2013 underwent ESD for colorectal tumors at our institution. We studied the clinical course and histologic features of perforation through a matched case-control study that included 24 patients with intraprocedural perforation and 240 matched patients without perforation as a control group. Endoscopic closure by using through-the-scope endoclips was attempted in all cases of intraprocedural perforations immediately after perforation was recognized during the procedure. RESULTS: Perforation occurred in 25 cases (2.7%), including 24 intraprocedural perforation and 1 delayed perforation. All but 1 patient with intraprocedural perforation was conservatively managed by endoscopic closure. One patient with unsuccessful endoscopic closure required emergency surgery. Analysis of clinical courses revealed statistically significant differences (P < .01) between the patients with perforation and the case-controlled, nonperforation patients in total procedure time, white blood cell count, and level of serum C-reactive protein on the day after the procedure, admission period, and fasting period. Both location (P = .027) and submucosal fibrosis (P = .04) of the lesion were significantly associated with perforation. Multivariate analysis revealed that fibrosis was a significant risk factor associated with perforation (odds ratio 2.86; 95% confidence interval, 1.03-7.90). CONCLUSIONS: Endoscopic closure allows effective nonsurgical management in cases of intraprocedural perforation during ESD.

Surveillance using capsule endoscopy is safe in post-colectomy patients with familial adenomatous polyposis: a prospective Japanese study.

The utility of capsule endoscopy (CE) for the surveillance of small intestinal lesions in familial adenomatous polyposis (FAP) patients has been reported. However, few studies have investigated the safety of CE in FAP patients who have undergone colon surgery. We aimed to assess the safety of surveillance CE in post-colectomy FAP patients and the endoscopic findings associated with small intestinal lesions. We assessed the safety of CE surveillance of small intestinal lesions in 41 FAP patients who had undergone colectomies. Forty-two CEs were performed in 41 patients at our facility from April 2012 to July 2014. CE was conducted safely and none of the capsules were retained, despite the inclusion of patients who had undergone several abdominal surgeries previously. Thirty-nine out of 42 capsules (93 %) were retrieved within the examination timeframe; hence, the retrieval rate was favorable. The findings from this study indicate that surveillance CE can be safely conducted in post-colectomy FAP patients.

Endocuff-assisted colonoscopy increases polyp detection rate: a simulated randomized study involving an anatomic colorectal model and 32 international endoscopists.

BACKGROUND: The undetected colonic lesions behind the folds and flexures are a major factor contributing to the adenoma miss rate. OBJECTIVE: To assess the efficacy of Endocuff, a special attachment was fixed at the distal tip of a colonoscope, for the polyp detection. This soft accessory is composed of a plastic cap surrounded by flexible finger-like projections on the lateral sides of the cap that make holding of the folds during scope withdrawal easier. DESIGN: This was a simulated pilot study with one anatomic colorectal model, containing 13 polyps positioned in obvious locations and behind the folds. Thirty-two endoscopists (16 Japanese and 16 foreign visitors) with different levels of experience performed examinations on the model in a randomized order by using Endocuff-assisted colonoscopy (EAC) and standard colonoscope (SC). MAIN OUTCOME MEASUREMENTS: To assess the detection rate of polyps and the feasibility of Endocuff insertion. RESULTS: EAC detected significantly more polyps than SC with 9.9 versus 7.5 mean lesions (p = 0.03), respectively, comparing the 16 first colonoscopies in each group. Endocuff was useful independent of the level of experience of the participants. After crossover, EAC in second position allowed an additional detection of 1.8 polyps compared with SC (p = 0.001). After adjustment on experience, time of detection, and order of colonoscopy, EAC over-detected 1.2 polyps (p = 0.0037). The insertion time (p = 0.99) was identical. There was no difference in the mean time of polyp detection between EAC and SC groups (p = 0.520). LIMITATIONS: This was not a clinical study. The stiffness of the folds in the colonic model was higher than in the human large bowel. CONCLUSION: EAC was associated with a higher polyp detection rate. Even in such relatively stiff anatomic model, it was easier to spread out the colonic mucosa between the folds using this cap. This study provides an additional argument for the routine application of this easy-to-use accessory to improve polyp detection.

The relationship between perioperative administration of inhaled corticosteroid and postoperative respiratory complications after pulmonary resection for non-small-cell lung cancer in patients with chronic obstructive pulmonary disease.

OBJECTIVES: Inhaled corticosteroid (ICS) treatment has been shown to increase the risk of respiratory complications in patients with stable chronic obstructive pulmonary disease (COPD). However, the effects of perioperative ICS treatment on postoperative respiratory complications after lung cancer surgery have not been elucidated. The aim of this study was to investigate whether perioperative ICS treatment would increase the risk of postoperative respiratory complications after lung cancer surgery in patients with COPD. METHODS: We retrospectively analyzed 174 consecutive COPD patients with non-small-cell lung cancer (NSCLC) who underwent lobectomy or segmentectomy between January 2007 and December 2014. Subjects were grouped based on whether or not they were administered perioperative ICS treatment. Postoperative cardiopulmonary complications were compared between the groups. RESULTS: There were no statistically significant differences in the incidence of postoperative respiratory complications (P = 0.573) between the perioperative ICS treatment group (n = 16) and the control group (n = 158). Perioperative ICS treatment was not significantly associated with postoperative respiratory complications in the univariate or multivariate analysis (odds ratio [OR] = 0.553, 95% confidence interval [CI] = 0.069-4.452, P = 0.578; OR = 0.635, 95% CI = 0.065-6.158, P = 0.695, respectively). Kaplan-Meier analysis showed that there were no statistically significant differences in the postoperative respiratory complications-free durations between the groups (P = 0.566), even after propensity score matching (P = 0.551). CONCLUSION: There was no relationship between perioperative ICS administration and the incidences of postoperative respiratory complications after surgical resection for NSCLC in COPD patients.

Association of gastric cancer risk factors with DNA methylation levels in gastric mucosa of healthy Japanese: a cross-sectional study.

Helicobacter pylori infection induces aberrant DNA methylation, and methylation levels of several specific marker genes in gastric mucosa are associated with gastric cancer risk. However, it is unclear whether gastric cancer risk factors are associated with methylation levels of marker genes in healthy individuals. We conducted a cross-sectional study of 281 Japanese cancer screenees aged 40-69 years with no history of H.pylori eradication therapy who responded to a validated food frequency questionnaire. DNA methylation levels of marker genes (miR-124a-3, EMX1 and NKX6-1) in gastric mucosa were quantified by real-time methylation-specific polymerase chain reaction. A multivariate beta regression model was used to investigate the association of pack-years of smoking and intakes of green/yellow vegetables, fruit and salt with methylation levels of marker genes. All analyses were stratified by H.pylori status. We found 2.5 to 34.1 times higher mean methylation levels among those with current H.pylori infection (n = 117) compared to those without (n = 164). After adjustment for potential confounders, we found increased levels of miR-124a-3 methylation according to pack-years of smoking and decreased levels of methylation according to green/yellow vegetable intake. We did not detect these associations among those without H.pylori infection. In conclusion, smoking habits and green/yellow vegetable intake were associated with DNA methylation levels in gastric mucosae of healthy individuals with current H.pylori infection. Our study suggests that these risk factors may modify the effect of H.pylori on methylation induction and maintenance in gastric mucosa.

Relationship between indeterminate or positive lateral margin and local recurrence after endoscopic resection of colorectal polyps.

BACKGROUND AND STUDY AIMS: Although endoscopic resection is widely used for the treatment of superficial colorectal neoplasms, the rate of local recurrence of lesions with a positive or indeterminate lateral margin on histologic evaluation is unclear. We aimed to demonstrate the relationship between lateral margin status and local recurrence after the endoscopic resection of intramucosal colorectal neoplasms. PATIENTS AND METHODS: We retrospectively collected the clinical and pathologic data for 844 endoscopically resected colorectal intramucosal neoplasms with a size of 10 mm or larger. We investigated the relationship between the local recurrence rate and the lateral margin status (categorized as LM0 [negative], LM1 [positive], or LMX [indeterminate]). RESULTS: In total, 389 lesions were evaluated as LM0 and showed no local recurrence. Of the 455 lesions evaluated as LMX or LM1, 30 showed local recurrence within a median period of 6.3 months (range, 1.7 - 48.1) from the initial endoscopic resection. The local recurrence rate of the en bloc-LMX group (2.2 %) was significantly lower than that of the piecemeal-LMX group (15.2 %). Of the 30 cases of recurrence, 28 were successfully treated with a second endoscopic resection. Of the two lesions that showed further recurrence, one was treated with a third endoscopic resection, whereas the other - which was a piecemeal-LMX lesion - was eventually diagnosed as invasive cancer and treated with surgery. CONCLUSIONS: The local recurrence rate was lower in the en bloc-LMX group than in the piecemeal-LMX group. Thus, we believe that en bloc-LMX lesions that are completely and confidently resected endoscopically can be treated as en bloc-LM0 lesions.

Excellent prognosis following endoscopic resection of patients with rectal neuroendocrine tumors despite the frequent presence of lymphovascular invasion.

BACKGROUND: Endoscopic resection (ER) has been increasingly used for the treatment of rectal neuroendocrine tumors (NETs); however, only limited data are available on its long-term outcomes. This study analyzed the long-term outcomes of rectal NETs treated by ER and characterized potential risk factors for metastasis in these cases, with emphasis on lymphovascular invasion. METHODS: We retrospectively analyzed the clinicopathological features and outcomes of 86 patients with 90 rectal NETs who had been treated by ER. Lymphovascular invasion was reevaluated using elastic-staining and double-staining immunohistochemistry. RESULTS: En bloc resection with tumor-free margins was achieved in 87 lesions (96.7%). The median tumor size was 5 mm (range 2-13), and all the lesions were confined to the submucosal layer. The Ki-67 index was less than 3% in all the lesions, which were therefore classified as NET G1. Elastic-staining and double-staining immunohistochemistry revealed the presence of lymphatic and venous invasion in 23 (25.6%) and 35 lesions (36.7%), respectively. Collectively, lymphatic and/or vascular invasion was identified in 42 lesions (46.7%). All cases were followed up without additional surgery, and no metastasis or recurrence was detected during the median follow-up period of 67.5 months. CONCLUSIONS: This study showed an excellent long-term prognosis following ER of patients with rectal NETs, confirming that ER is a valid treatment option for small rectal NETs. The present study also revealed highly prevalent lymphovascular invasion even in minute rectal NETs; this observation raises a question regarding its significance as a risk factor for metastasis.

Investigating endoscopic features of sessile serrated adenomas/polyps by using narrow-band imaging with optical magnification.

BACKGROUND: A sessile serrated adenoma/polyp (SSA/P) is a common type of colorectal polyp that possesses malignant potential. Although narrow-band imaging (NBI) can easily differentiate neoplastic lesions from hyperplastic polyps (HPs), SSA/Ps can be a challenge to distinguish from HPs. OBJECTIVE: To investigate specific endoscopic features of SSA/Ps by using NBI with optical magnification. DESIGN: Retrospective study. SETTING: Single high-volume referral center. PATIENTS: A total of 289 patients with histopathologically proven SSA/Ps or HPs obtained from colonoscopic polypectomy. INTERVENTION: Endoscopic images obtained by using NBI with optical magnification of 242 lesions (124 HPs, 118 SSA/Ps) removed between January 2010 and December 2012 were independently evaluated by 2 experienced endoscopists. Three external experienced endoscopists systematically validated the diagnostic accuracies by using 40 lesions (21 HPs and 19 SSA/Ps) removed between January and March 2013. MAIN OUTCOME MEASUREMENTS: Specific endoscopic features of SSA/Ps by using 5 potential characteristics: dilated and branching vessels (DBVs), irregular dark spots, a regular network pattern, a disorganized network pattern, and a dense pattern. RESULTS: Multivariate analysis demonstrated that DBV had a 2.3-fold odds ratio (95% confidence interval, 0.96-5.69) among SSA/Ps compared with HPs (sensitivity, 56%; specificity, 75%; accuracy, 65%). Interobserver and intraobserver agreement indicated almost perfect agreement for DBVs in both the evaluation and validation studies. When DBVs, proximal location, and tumor size (≥10 mm) were combined, the positive predictive value was 92% and the area under the curve was 0.783 in the receiver-operating characteristics by using the validation group. LIMITATIONS: Retrospective study. CONCLUSIONS: The current study suggests that a DBV is a potentially unique endoscopic feature of a colorectal SSA/P.

Potential perioperative advantage of colorectal endoscopic submucosal dissection versus laparoscopy-assisted colectomy.

BACKGROUND: Endoscopic submucosal dissection (ESD) has recently provided a new treatment strategy for large colorectal neoplasms, as an alternative to laparoscopy-assisted colectomy (LAC). Prospective comparative data on the perioperative course of ESD vis-à-vis LAC are scarce. METHODS: We prospectively evaluated the perioperative course of colorectal ESD in 300 patients. We evaluated en bloc and curative resection, procedure duration, postoperative parameters [white blood cell count (WBC), C-reactive protein (CRP), and hemoglobin], pain, recovery duration (time to achieve full mobilization, normal diet, and length of hospitalization), and complications. We also prospectively evaluated 190 patients undergoing LAC as a control group. RESULTS: The median size of the lesions was 30 mm for ESDs (LACs: 20 mm). The median procedure time was 90 min for ESDs (LACs: 185 min). Postoperative pyrexia was reported in 4 % of ESDs (LACs: 54 %). Only 4 % of ESDs required analgesia (LACs: 61 %). Between the preoperative period and postoperative day 1, the mean difference in WBC and CRP was +1,300/µl for ESDs (LACs: +3,100/µl), and +0.91 mg/dl for ESDs (LACs: +3.96 mg/dl), respectively. A ≥2 g/dl decrease in hemoglobin was observed in 5 % of ESDs (LACs: 30.0 %). Complications were seen in 7 % of ESDs (LACs: 15 %). The rate of delayed bleeding and perforation was 5 and 1.7 % of ESDs, respectively. Although only one of them required laparotomy for peritonitis caused by delayed perforation, others could be managed endoscopically. Additional LAC was required in 16 ESDs due to redefined risk for lymph node metastases. The median hospital stay was 5 days for ESDs (LACs: 10 days). These were consecutive patients with prospective data collection. CONCLUSIONS: Colorectal ESD is effective, minimally invasive and safe in terms of periperative clinical course. Colorectal ESD provides advantages for treatment of large adenomas and early cancers with no risk of lymph node metastasis.