Clinical outcomes and learning curve of Tip-in endoscopic mucosal resection for 15-25 mm colorectal neoplasms among non-experts

BACKGROUND AND AIM

Tip-in endoscopic mucosal resection (EMR) has a high en bloc resection rate for large colorectal neoplasms. However, non-experts' performance in Tip-in EMR has not been investigated. We investigated whether Tip-in EMR can be achieved effectively and safely even by non-experts.

METHODS

This retrospective study included consecutive patients who underwent Tip-in EMR for 15-25 mm colorectal nonpedunculated neoplasms at a Japanese tertiary cancer center between January 2014 and December 2020. Baseline characteristics, treatment outcomes, learning curve of non-experts, and risk factors of failing self-achieved en bloc resection were analyzed.

RESULTS

A total of 597 lesions were analyzed (438 by experts and 159 by non-experts). The self-achieved en bloc resection (69.8% vs 88.6%, P < 0.001) and self-achieved R0 resection (58.3% vs 76.5%, P < 0.001) rates were significantly lower in non-experts with <10 cases of experience than in experts, but not in non-experts with >10 cases. Adverse event (P = 0.165) and local recurrence (P = 0.892) rates were not significantly different between experts and non-experts. Risk factors of failing self-achieved en bloc resection were non-polypoid morphology (OR 3.4, 95% CI 1.6-7.3, P = 0.001), lesions with an underlying semilunar fold (OR 3.6, 95% CI 1.6-7.3, P < 0.001), positive non-lifting sign (OR 3.1, 95% CI 1.2-8.0, P = 0.023), and non-experts with an experience of ≤10 cases (OR 3.6, 95% CI 2.1-6.3, P < 0.001).

CONCLUSION

The clinical outcomes of Tip-in EMR for 15-25 mm lesions performed by non-experts were favorable.

A Japanese Family Meeting the Clinical Diagnostic Criteria for MEN1 with a MEN1 Variant of Uncertain Significance

Multiple gastroenteric, pancreatic, and pituitary neuroendocrine neoplasms (NENs) were diagnosed in a 74-year-old man with a history of primary hyperparathyroidism (PHPT). Germline testing demonstrated a variant of MEN1 (c.1694T>A, p.L565Q), whose pathogenicity was classified as a variant of uncertain significance (VUS) according to the ACMG/AMP guidelines. The same germline variant was detected in the patient's son and daughter, who also showed PHPT or hypercalcemia and met the clinical diagnostic criteria for multiple endocrine neoplasia type 1 (MEN1). During surveillance of the son, multiple pancreatic tumors suggestive of NENs were detected. The pathogenicity of the current MEN1 variant was re-evaluated as likely pathogenic, based on additional family data.

A novel low-power pure-cut hot snare polypectomy for 10-14 mm colorectal adenomas: An ex vivo and a clinical prospective feasibility study (SHARP trial)

BACKGROUND AND AIM

Hot snare polypectomy using blend or coagulation current is widely used; however, it causes deeper tissue heat injury, leading to adverse events. We hypothesized that hot polypectomy using low-power pure cut current (PureCut, effect 1 10 W) could reduce deeper tissue heat injury. We conducted animal experiments to evaluate the deeper tissue heat injury and conducted a prospective clinical study to examine its cutting ability.

METHODS

In a porcine rectum, hot polypectomy using Blend current (EndoCut, effect 3 40 W) and low-power pure cut current was performed. The deepest part of heat destruction and thickness of the non-burned submucosal layer were evaluated histologically. Based on the results, we performed low-power pure cut current hot polypectomy for 10-14 mm adenoma. The primary endpoint was complete resection defined as one-piece resection with negative for adenoma in quadrant biopsies from the defect margin.

RESULTS

In experiments, all low-power pure-cut resections were limited within the submucosal layer whereas blend current resections coagulated the muscular layer in 13% (3/23). The remaining submucosal layer was thicker in low-power pure cut current than in blend current resections. In the clinical study, low-power pure-cut hot polypectomy removed all 100 enrolled polyps. For 98 pathologically neoplastic polyps, complete resection was achieved in 84 (85.7%, 95% confidence interval, 77-92%). The lower limit of the 95% confidence interval was not more than 15% below the pre-defined threshold of 86.6%. No severe adverse events occurred.

CONCLUSIONS

A novel low-power pure-cut hot polypectomy may be feasible for adenoma measuring 10-14 mm. (UMIN000037678).

Evaluating false-positive detection in a computer-aided detection system for colonoscopy

BACKGROUND AND AIM

Computer-aided detection (CADe) systems can efficiently detect polyps during colonoscopy. However, false-positive (FP) activation is a major limitation of CADe. We aimed to compare the rate and causes of FP using CADe before and after an update designed to reduce FP.

METHODS

We analyzed CADe-assisted colonoscopy videos recorded between July 2022 and October 2022. The number and causes of FPs and excessive time spent by the endoscopist on FP (ET) were compared pre- and post-update using 1:1 propensity score matching.

RESULTS

During the study period, 191 colonoscopy videos (94 and 97 in the pre- and post-update groups, respectively) were recorded. Propensity score matching resulted in 146 videos (73 in each group). The mean number of FPs and median ET per colonoscopy were significantly lower in the post-update group than those in the pre-update group (4.2 ± 3.7 vs 18.1 ± 11.1; P < 0.001 and 0 vs 16 s; P < 0.001, respectively). Mucosal tags, bubbles, and folds had the strongest association with decreased FP post-update (pre-update vs post-update: 4.3 ± 3.6 vs 0.4 ± 0.8, 0.32 ± 0.70 vs 0.04 ± 0.20, and 8.6 ± 6.7 vs 1.6 ± 1.7, respectively). There was no significant decrease in the true positive rate (post-update vs pre-update: 95.0% vs 99.2%; P = 0.09) or the adenoma detection rate (post-update vs pre-update: 52.1% vs 49.3%; P = 0.87).

CONCLUSIONS

The updated CADe can reduce FP without impairing polyp detection. A reduction in FP may help relieve the burden on endoscopists.

A Japanese case of ovarian mucinous adenocarcinoma with germline double variants of MSH2 and BRCA2

Germline double heterozygosity (GDH) is rarely reported in cases of inherited cancer syndromes, and GDH of a mismatch repair gene and BRCA has never been reported in Japan. Nonetheless, the current report demonstrates a case of ovarian mucinous adenocarcinoma with initiated Lynch syndrome (LS)-related surveillance because of a known germline MSH2 variant. Six and a half years after oophorectomy, multiple tumors developed in the patient's lungs, bones, and lymph nodes, and histology results confirmed mucinous adenocarcinoma. Systemic chemotherapy including an anti-PD-L1 antibody was effective for >1 year, but brain metastases developed. Pathology of the brain tumors showed mucinous adenocarcinoma without expression of MSH2 and MSH6, while multi-gene panel testing demonstrated not only high microsatellite instability and a high tumor mutation burden, but also germline BRCA2 variants. Further, germline testing in relatives confirmed both variants were from the paternal line, from which many LS-related cancers develop, but not BRCA-related cancer.

Endoscopic causes and characteristics of missed gastric cancers after endoscopic submucosal dissection

BACKGROUND AND AIMS

Because endoscopic submucosal dissection (ESD) for early gastric cancer (EGC) preserves the entire stomach, missed gastric cancers (MGCs) are often found in the remaining gastric mucosa. However, the endoscopic causes of MGCs remain unclear. Therefore, we aimed to elucidate the endoscopic causes and characteristics of MGCs after ESD.

METHODS

From January 2009 to December 2018, all patients undergoing ESD for initially detected EGC were enrolled. According to a review of EGD images before ESD, we identified the endoscopic causes (perceptual, exposure, sampling errors, and inadequate preparation) and characteristics of MGC in each endoscopic cause.

RESULTS

Of 2208 patients who underwent ESD for initial EGC, 82 patients (3.7%) had 100 MGCs. The breakdown of endoscopic causes of MGCs was as follows: 69 (69%) perceptual errors, 23 (23%) exposure errors, 7 (7%) sampling errors, and 1 (1%) inadequate preparation. Logistic regression analysis showed that the risk factors for perceptual error were male sex (odds ratio [OR], 2.45; 95% confidence interval [CI], 1.16-5.18), isochromatic coloration (OR, 3.17; 95% CI, 1.47-6.84), greater curvature (OR, 2.31; 95% CI, 1.121-4.40), and lesion size ≤12 mm (OR, 1.74; 95% CI, 1.07-2.84). The sites of exposure errors were around the incisura angularis (11 [48%]), posterior wall of the gastric body (6 [26%]), and antrum (5 [21%]).

CONCLUSIONS

We identified MGCs in 4 categories and clarified their characteristics. Quality improvements in EGD observation, with attention to the risks of perceptual and site of exposure errors, can potentially prevent missing EGCs.

Discordant microsatellite instability findings in two samples from a patient with biliary cancer that responded to pembrolizumab

Microsatellite instability (MSI) is a key marker to predict response to immune checkpoint inhibitors; however, only 1-2% of biliary cancers have this genomic feature. In a patient with hilar biliary cancer, MSI was examined in two cancer specimens (forceps biopsy from the biliary stricture and endoscopic ultrasound-guided fine-needle aspiration biopsy [EUS-FNAB] from the adjacent lymph node). We observed discordant results, as high frequency of MSI was found only in the forceps biopsy. Although the FNAB sample was 10 times larger than that of the forceps biopsy, the tumor concentration was much lower, which is a possible reason for the discordance. Besides, immunohistochemistry of four mismatch-repair (MMR) proteins showed proficient MMR expressions. The tumor became refractory to gemcitabine, cisplatin, and S-1 but responded well to pembrolizumab. Caution is needed for sample selection and for interpretation of the test's results, to avoid missing rare chance for effective molecular target agents.

Local recurrence risk of esophageal squamous cell carcinoma due to intralesional damage during endoscopic submucosal dissection

BACKGROUND AND AIM

It is unclear whether additional treatment should be considered given the recurrence risk after endoscopic submucosal dissection (ESD) for esophageal squamous cell carcinoma (ESCC) when the vertical margin is positive or unclear (VM1/VMX) due to intralesional damage. This study aimed to elucidate the local recurrence risk of ESCC caused by intralesional damage during ESD.

METHODS

Among consecutive patients with pT1a ESCCs initially treated by ESD at our institution between January 2006 and December 2018, ESCCs diagnosed as VM1/VMX were retrospectively reviewed. Exclusion criteria were piecemeal resection and any additional treatment after ESD. Intralesional damage included the following three types: a macroscopic hole inside the lesion, an incision from the lateral margin of the specimen into the lesion, and crushing injury or burn effect into the deepest area of the lesion without an obvious hole. The local recurrence rate after ESD was primarily analyzed.

RESULTS

Of 1174 pT1a ESCCs initially treated using ESD, 22 lesions were histopathologically diagnosed as VM1/VMX due to intralesional damage (1.9%; 95% confidence interval [CI], 1.2-2.8%). At a median follow-up period of 60.0 (interquartile range, 15.0-84.0) months, no local recurrence was observed (0.0%; 95% CI, 0.0-13.3%) among 21 lesions finally evaluated.

CONCLUSIONS

The impact of intralesional damage during ESD for ESCC on local recurrence might be negligible. Follow-up without additional treatment may be acceptable even if intralesional damage occurs and results in VM1/VMX after ESD for pT1a ESCCs.

Optimization of endoscopic ultrasound-guided tissue sample acquisition for commercially available comprehensive genome profiling

BACKGROUND AND AIM

Optimal tumor samples are crucial for successful analysis using commercially available comprehensive genomic profiling (CACGP). However, samples acquired by endoscopic ultrasound-guided tissue acquisition (EUS-TA) are occasionally insufficient, and no consensus on the optimal number of needle passes required for CACGP exists. This study aimed to explore the optimal number of needle passes required for EUS-TA to procure an ideal sample fulfilling the prerequisite criteria of CACGPs.

METHODS

Patients who underwent EUS-TA for solid masses between November 2019 and July 2021 were retrospectively studied. The correlation between the acquisition rate of an ideal sample and the number of needle passes mounted on a microscope slide was evaluated. Additionally, the factors predicting a successful analysis were investigated in patients scheduled for CACGP using EUS-TA-obtained samples during the same period.

RESULTS

EUS-TAs using 22- and 19-gauge (G) needles were performed in 336 and 57 patients, respectively. There was a positive correlation between the acquisition rate and the number of passes using a 22-G needle (38.9%, 45.0%, 83.7%, and 100% for 1, 2, 3, and 4 passes, respectively), while no correlation was found with a 19-G needle (84.2%, 83.3%, and 85.0% for 1, 2, and 3 passes, respectively). The analysis success rate in patients with scheduled CACGP was significantly higher with ideal samples than with suboptimal samples (94.1% vs 55.0%, P < 0.01).

CONCLUSIONS

The optimal estimated number of needle passes was 4 and 1-2 for 22- and 19-G needles, respectively.

Clinical risk management of breast, ovarian, pancreatic, and prostatic cancers for BRCA1/2 variant carriers in Japan

Opportunities for genetic counseling and germline BRCA1/2 (BRCA) testing are increasing in Japan owing to cancer genomic profiling testing and companion diagnostics being covered by national health insurance for patients with BRCA-related cancers. These tests are useful not only to judge whether platinum agents and PARP inhibitors are indicated but also to reveal an autosomal-dominant inherited cancer syndrome: hereditary breast and ovarian cancer. In individuals with germline BRCA variants, risk of cancers of the breast, ovary, pancreas, and prostate is significantly increased at various ages of onset, but the stomach, uterus, biliary tract, and skin might also be at risk. For women with pathogenic BRCA variants, breast awareness and image analyses should be initiated in their 20s, and risk-reducing procedures such as mastectomy are recommended starting in their 30s, with salpingo-oophorectomy in their late 30s. For male BRCA pathogenic variant carriers, prostatic surveillance should be applied using serum prostate-specific antigen starting in their 40s. For both sexes, image examinations ideally using endoscopic ultrasound and magnetic resonance cholangiopancreatography and blood testing should begin in their 50s for pancreatic surveillance. Homologous recombination pathway-associated genes are also causative candidates. Variant pathogenicity needs to be evaluated every 6-12 months when results are uncertain for clinical significance. Genetic counseling needs to be offered to the blood relatives of the pathogenic variant carriers with suitable timing. We review the recommended cross-organ BRCA risk management in Japan.

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.

A Cross-sectional Study of Regret in Cancer Patients After Sharing Test Results for Pathogenic Germline Variants of Hereditary Cancers With Relatives

BACKGROUND

Research on whole genome/exome sequencing is increasing worldwide. However, challenges are emerging in relation to receiving germline pathogenic variant results and sharing them with relatives.

OBJECTIVE

The aim of this study was to investigate the occurrence of and reasoning related to regret among patients with cancer who shared single-gene testing results and whole exome sequencing with family members.

METHODS

This was a single-center, cross-sectional study. The Decision Regret Scale was administered, and descriptive questionnaires were used with 21 patients with cancer.

RESULTS

Eight patients were classified as having no regret, 9 patients were classified as having mild regret, and 4 patients were classified as having moderate to strong regret. Reasons patients felt that sharing was the right decision included the following: to allow relatives and children to take preventive measures, the need for both parties to be aware of and ready for the hereditary transmission of cancer, and the need to be able to discuss the situation with others. On the other hand, some patients did not think it was a good decision to share the information because of the associated anxiety.

CONCLUSIONS

Regret over sharing test results for pathogenic germline variants of hereditary cancers with relatives tended to be low. The main reason was that patients believed that they were able to benefit others by sharing.

IMPLICATIONS FOR PRACTICE

Healthcare professionals need to understand the postsharing perceptions and experiences of patients and support them throughout the sharing process.

Efficacy and Safety of Gel Immersion Endoscopic Mucosal Resection for Non-Pedunculated Colorectal Polyps

Underwater endoscopic mucosal resection (UEMR) has become a popular endoscopic resection method for large colorectal neoplasms. However, visualization can be poor during UEMR due to the presence of intestinal fluid. Gel immersion endoscopic mucosal resection (GIEMR), using a specially developed gel (Viscoclear®, Otsuka Pharmaceutical Factory, Tokushima, Japan), can improve the visual field. However, reports of GIEMR for colorectal polyps are limited. Herein, we evaluated the short-term outcomes of GIEMR for non-pedunculated colorectal neoplasms (NPCRN). This single-center, retrospective, and observational study includes 25 lesions in 20 patients with NPCRN who underwent GIEMR between January and October 2022. The short-term outcomes and adverse events were evaluated. The lesion locations were as follows: right colon, 18 lesions; left colon, 7 lesions; and rectum, none. The median tumor diameter was 15 (IQR, 10–18) mm. Histological classification was as follows: sessile serrated lesion, 9 cases; adenoma, 12 cases; and intramucosal adenocarcinoma, 4 cases. The overall en bloc resection rates and R0 resection rates were 80% (20/25) and 72% (18/25). For NPCRN in 10–19 mm, the en bloc resection rate was 75% (12/16), with an R0 resection rate of 69% (11/16). No post-polypectomy bleeding, perforation, or post-coagulation syndrome were observed. The findings of our study provide preliminary evidence of the efficacy and safety of GIEMR for NPCRN. Therefore, GIEMR may be a promising novel endoscopic resection method for NPCRN.

Genetic medicine in companion diagnostics of germline BRCA testing of Japanese pancreatic cancer patients

In 2021, Japan's national health insurance made germline BRCA (g.BRCA) testing available to unresectable pancreatic cancer (PC) patients as a companion diagnostic (CD) of the PARP inhibitor. This study investigated the incidence of the g.BRCA variant (g.BRCAv.) and the status of the genetic medicine associated with its testing. A total of 110 PC patients underwent the testing, five of whom (4.5%) had a deleterious g.BRCA2v. (all truncations) but no g.BRCA1v. The turnaround time (TAT) to the doctors was 13 days, and to the patients, 17 days. A higher incidence of a BRCA-related family history and a shorter TAT were seen in the g.BRCAv. patients, but they were insignificant (p = 0.085 and p = 0.059, respectively). Genetic counseling was not performed for three g.BRCA2v. patients because two of them had no accessible relatives and one died of the cancer before the genetic report was completed. Two families underwent generic counseling and testing based on the patient's genetic data. g.BRCAv. is recognized in a small fraction of PC cases, and the following genetic counseling is done more for the relatives than for the patients. TAT was constant and did not affect much on the genetic counseling, but the earlier testing is expected for patients with a deadly cancer.

Clinical outcomes of endoscopic submucosal dissection for superficial circumferential esophageal squamous cell carcinoma

BACKGROUND AND AIMS

Our aim was to elucidate the clinical outcomes of endoscopic submucosal dissection (ESD) for superficial circumferential esophageal squamous cell carcinoma (cESCC).

METHODS

Consecutive patients who underwent ESD for cESCC between 2009 and 2020 were retrospectively reviewed. Short-term outcomes were en-bloc resection, R0 resection, procedure time, and adverse events, whereas long-term outcomes were overall survival (OS), disease-specific survival (DSS), cumulative recurrence rate (CRR), and clinical course.

RESULTS

Fifty-two patients with 52 cESCCs (median tumor length, 5.0 cm; interquartile range [IQR], 4.0-6.3) were evaluated. The en-bloc resection and R0 resection rates were 100% (95% confidence interval [CI], 94.4-100) and 69.2% (95% CI, 54.9-81.3), respectively. The median procedure time was 112 minutes (IQR, 87-162). Intraoperative perforations and delayed bleeding occurred in 4 (7.7%) and 1 (1.9%) patients, respectively. Among the 42 patients who underwent ESD alone, 36 (85.7%) experienced esophageal strictures. Within a median follow-up of 49.1 months (IQR, 25.7-74.7), the 4-year OS, DSS, and CRR were 86.2% (95% CI, 71.6-93.6), 95.5% (95% CI, 83.1-98.9), and 11.5% (95% CI, 4.1-23.1), respectively. There was no significant difference in the OS between patients with low-risk cESCC (pT1a, negative lymphovascular invasion, and negative vertical margin) and high-risk lesions, regardless of undergoing additional treatment (P = .93). In 31 patients with low-risk cESCC who were treated with ESD alone, the 4-year OS, DSS, and CRR were 93.2%, 100%, and 0%, respectively.

CONCLUSIONS

ESD is a highly curative treatment for cESCC with favorable long-term outcomes, especially in low-risk patients. Stricture-prevention techniques should be improved to optimize the benefits of ESD for cESCC.

Discordance of microsatellite instability and mismatch repair immunochemistry occurs depending on the cancer type

Microsatellite instability (MSI) and deficiency of mismatch repair (dMMR) are key markers for predicting the response of immune checkpoint inhibitors (ICIs) and screening for Lynch syndrome (LS). This study examined the incidences of and factors associated with the concordance of MSI and MMR in human cancers. A total of 518 formalin-fixed cancer tissues were analyzed for MSI and MMR immunohistochemistry (IHC). MSI was analyzed by a PCR-based method using Promega markers. Concordance with MMR expression and factors associated with concordance were analyzed. In 2 colorectal cancer samples, MMR IHC failed due to inadequate staining conditions. In the remaining 516 cancers, a high level of MSI (MSI-H) was identified in 113 cases, and dMMR was identified in 112. The concordance of MSI and MMR IHC was 98.3%. Only 9 cases (4 pancreatobiliary, 3 colorectal, and 2 endometrial cancers) were discordant. Of the 113 MSI-H cases, 4 (3.5%) were proficient MMR (pMMR); of the 403 microsatellite stability (MSS) cases, 5 (1.2%) were dMMR. The independent factors associated with MSI-H/dMMR included meeting Amsterdam II criteria, assay purpose, and sampling method. Multivariate analysis revealed that cancer type (gastrointestinal cancers or others) was associated with concordance of MSI and MMR IHC. Three LS cases with pancreatic or endometrial cancer demonstrated MSS and dMMR, and one biliary cancer showed MSI-H and pMMR. Discordance between MSI and MMR IHC occasionally occurs in pancreaticobiliary and endometrial cancers. When suspected, both MSI and MMR IHC should be done to judge the ICI indication and screen for LS.

Diagnostic performance of endoscopy for subsquamous extension of superficial adenocarcinoma of the esophagogastric junction

OBJECTIVES

Extension of adenocarcinoma of the esophagogastric junction under the squamous epithelium may lead to errors when determining lateral margins. However, the characteristics of subsquamous extension are unclear. Herein, we evaluated the prevalence and characteristics of subsquamous extension of adenocarcinoma of the esophagogastric junction and the diagnostic performance of endoscopy for this condition.

METHODS

Eighty-nine consecutive patients with superficial adenocarcinoma of the esophagogastric junction who underwent endoscopic or surgical resection at a tertiary cancer center between January 2010 and December 2017 were retrospectively evaluated. Endoscopic subsquamous extension was defined as a submucosal tumor-like elevation covered by squamous epithelium and/or a brownish area with abnormal microvessels on the squamous epithelium observed using narrow-band imaging. The diagnostic performance of endoscopy for subsquamous extension was evaluated using histological subsquamous extension as gold standard.

RESULTS

Thirty-nine patients (44%) had histological subsquamous extension. Proton pump inhibitor use was significantly associated with histological subsquamous extension [odds ratio: 4.65; 95% confidence interval (CI): 1.77-12.2]. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of endoscopic subsquamous extension were 56% (95% CI: 40-72%), 96% (86-99%), 92% (73-99%), 74% (62-84%) and 79% (69-87%), respectively. The median length difference between histological and endoscopic subsquamous extension was 2 mm (range: -6 to 9 mm).

CONCLUSIONS

The sensitivity of endoscopic diagnosis of subsquamous extension was unsatisfactory. The endoscopic length of subsquamous extension tended to be underestimated. An oral safety margin of one centimeter is reasonable during endoscopic resection of adenocarcinoma of the esophagogastric junction.IMPACT STATEMENT This study will contribute significantly to the literature because this is the first study to determine the difference between the lengths of subsquamous extension detected endoscopically and histologically. This study determines the prevalence of subsquamous extension and identifies characteristics associated with subsquamous extension. An understanding of the risk of subsquamous extension is important when choosing a treatment strategy and planning the resection margins in patients with adenocarcinoma of the esophagogastric junction. This study provides patients with subsquamous extension characteristics and suggests a method for accurately diagnosing this condition.

Tip-in EMR as an alternative to endoscopic submucosal dissection for 20- to 30-mm nonpedunculated colorectal neoplasms

BACKGROUND AND AIMS

Tip-in EMR, which includes anchoring the snare tip, has recently shown a favorable en-bloc and R0 resection rate for colorectal neoplasms. Thus, Tip-in EMR may be an alternative to endoscopic submucosal dissection (ESD). We aimed to compare clinical outcomes between Tip-in EMR and ESD for large colorectal neoplasms.

METHODS

This retrospective study evaluated consecutive patients who underwent Tip-in EMR or ESD for 20- to 30-mm nonpedunculated colorectal neoplasms at a Japanese tertiary cancer center between January 2014 and December 2019. Baseline characteristics, treatment results, and long-term outcomes were analyzed using 1:1 propensity score matching.

RESULTS

Seven hundred nine lesions were evaluated. The Tip-in EMR group included 1 lesion with a nonlifting sign but no lesions with fold convergence. After propensity score matching, each group included 140 lesions. The ESD group showed significantly higher en-bloc resection rates (99.3% vs 85.0%) and R0 resection rates (90.7% vs 62.9%). Procedure time was significantly shorter in the Tip-in EMR group (8 minutes vs 60 minutes). The Tip-in EMR and ESD groups did not differ significantly with respect to local recurrence rate (2.1% vs 0%).

CONCLUSIONS

Tip-in EMR is comparable with ESD with respect to the local recurrence rate but has a shorter procedure time, despite the lower en-bloc and R0 resection rates for 20- to 30-mm nonpedunculated colorectal neoplasms without fold convergence or nonlifting sign. Thus, Tip-in EMR could be a feasible alternative to ESD in these lesions.

Diagnostic ability of magnification endoscope with narrow-band imaging in screening esophagogastroduodenoscopy

OBJECTIVES

Magnifying endoscopy with narrow-band imaging (M-NBI) is useful for the optical diagnosis of gastrointestinal neoplasms. However, the utility of M-NBI in screening esophagogastroduodenoscopy (EGD) is unclear. We aimed to evaluate the diagnostic ability of the magnification endoscope (ME) in screening EGD for a population with a low prevalence of upper gastrointestinal cancers.

METHODS

Overall, 4887 asymptomatic examinees without a history of laryngopharyngeal and/or upper gastrointestinal neoplasms who underwent opportunistic screening EGD between April 2011 and December 2017 were enrolled in this retrospective study. The examinees were categorized into two groups depending on whether screening EGD was performed using ME (ME group) or not (non-ME group). Using a propensity score-matched analysis, the diagnostic ability of EGD was compared between the two groups.

RESULTS

In total, 1482 examinees (30%) were allocated to the ME group and 3405 (70%) to the non-ME group. Thirty-five epithelial neoplasms were detected in 30 examinees (0.6%). The groups were matched for baseline characteristics (1481 pairs). Both groups showed no significant difference in the epithelial neoplasm detection rate (0.8% vs. 0.3%; P = 0.14). The biopsy rate was significantly lower in the ME group than in the non-ME group (12% vs. 15%; P = 0.003). The positive predictive value (PPV) for biopsy was significantly higher in the ME group than in the non-ME group (6.6% vs. 2.8%; P = 0.048).

CONCLUSIONS

Using an ME for screening EGD in an apparently healthy, asymptomatic population could reduce unnecessary biopsies by improving PPV for biopsy without decreasing the epithelial neoplasm detection rate.

P-127 Identification of the optimal puncture position by image analysis may reduce oocyte degeneration in intracytoplasmic sperm injection (ICSI)

Study question

Is it possible to identify the optimal puncture position by image analysis where oocyte degeneration is reduced in ICSI procedure?

Summary answer

Visualizing the likelihood of unintentional membrane rupture (UMR) using image analysis can reduce oocyte degeneration and thereby generate more embryos available for treatment.

What is known already

It is known that the oocyte degeneration after both conventional-ICSI and Piezo-ICSI are often observed when UMR occurs during the puncturing process and the likelihood of UMR may depends on the location of the puncture site on the oolemma. Identifying the appropriate puncturing position may decrease the likelihood of membrane rupture and thus degeneration, however, there are no studies identifying the optimal puncture position during ICSI.

Study design, size, duration

We have developed the ICSI Position Detector (IPD), which can identify an area where rupture is likely to occur and visualize it on a video monitor. This study included 1,110 mature oocytes retrieved from 190 consenting patients. Matured oocytes were inseminated either by Conventional-ICSI (n = 437, average maternal age: 39.1±4.6 y.o.) or Piezo-ICSI (n = 673, average maternal age: 38.6±4.5 y.o.). ICSI was performed blindly, moving images were recorded and analyzed retrospectively during ICSI using IPD.

Participants/materials, setting, methods

Inseminated oocytes were subsequently divided into two groups according to IPD results, oocytes on which ICSI was performed at the position with a low chance of UMR (appropriate group), and with a high chance of UMR (non-appropriate group) by IPD. The rates of UMR, degeneration, fertilization (2PN), blastocyst formation, and good-quality blastocyst (Grade 3BB and above on day 5 by the Gardner scoring) were compared between the two groups of both conventional-ICSI and Piezo-ICSI.

Main results and the role of chance

The areas in which UMR is less likely to occur and more likely to occur are heterogeneously distributed. When ICSI was performed blindly, about half was from the non-appropriate position. In appropriate group of Piezo-ICSI, rates of UMR (4.3% vs. 17.4%, P &lt; 0.001) and degeneration (1.0% vs. 5.7%, P &lt; 0.001) were significantly lower than those of non-appropriate group, whereas rates of fertilization (88.0% vs. 78.4%, P &lt; 0.01) and blastocyst formation (57.8% vs. 45.9%, P &lt; 0.01) were significantly higher than those of non-appropriate group, respectively. The rate of good-quality blastocyst (28.8% vs. 24.9%) was in favor of appropriate group, but not significantly different. In appropriate group of Conventional-ICSI, rates of UMR (6.7% vs. 20.6%, P &lt; 0.001) and degeneration (1.5% vs. 6.6%, P &lt; 0.01) were significantly lower than those of non-appropriate group, whereas rate of fertilization (88.7% vs. 69.5, P &lt; 0.001) was significantly higher than those of non-appropriate group, respectively. The rates of blastocyst formation (37.5% vs. 35.3%), good-quality blastocyst (21.3% vs. 18.7%) were all in favor of appropriate group, but not significantly different.

Limitations, reasons for caution

This is a single private fertility clinic study. Its reproducibility should be assessed in different laboratory conditions and the hands of different operators. Moreover, specific studies should be addressed on the effect of the other putative confounders under investigation (e.g. kind of ovulation trigger, patient demographics, culture environment, etc.).

Wider implications of the findings

This study demonstrated that the IPD is useful to identify the optimal puncture location site to prevent UMR on ICSI procedure, resulting in reducing UMR and degeneration of the oocytes and increasing culture results, thereby, generating more embryos available for transfer or cryopreservation.

Trial registration number

not applicable

O-207 Incidence of Y chromosome microdeletions and microdissection testicular sperm extraction (micro TESE) in patients with Japanese azoospermic patients

Study question

What is the frequency of azoospermia factor (AZF) microdeletions and sperm retrieval rate (SRR) by micro TESE in patients with these deletions?

Summary answer

AZFc is most frequent of Y chromosome microdeletions and a predictor of micro TESE outcome in Japanese azoospermic men.

What is known already

After Klinefelter syndrome, Y chromosome microdeletions are the second most frequent genetic cause of male infertility, with a prevalence of 2%-10% in non-obstructive azoospermia (NOA) and three spermatogenesis loci in the Y chromosome long arm (Yq11) have been classified as AZFa, AZFb, and AZFc. The classical correlation of histopathology phenotypes with these three microdeletions comprises of complete absence of germ cells (Sertoli cell-only syndrome) in patients with AZFa microdeletions, maturation arrest of meiosis in patients with AZFb microdeletions, and hypospermatogenesis in patients with AZFc microdeletions, however, individual variation in the extent of deletions has led to various spermatogenic phenotypes.

Study design, size, duration

We performed a retrospective study based on two reproduction centers in Japan and evaluated 1373 azoospermic patients in our clinics between September 2013 and December 2021. We investigated the frequency of AZF microdeletions and SRR by micro TESE in patients with these microdeletions and therefore aimed to evaluate the correlation between AZF microdeletions and micro TESE results.

Participants/materials, setting, methods

A total of 1373 azoospermic were enrolled. After the diagnosis of azoospermia, karyotype analysis and detection of Y chromosome microdeletions were performed on peripheral blood lymphocytes of these patients. Y chromosome microdeletions in AZFa, AZFb, and AZFc regions were detected using Promega Y Chromosome AZF Analysis System version 2.0 (Promega Co.). Twenty sequence-tagged sites within the AZF region of Yq11 and the sex-determining region Y gene were targeted for polymerase chain reaction (PCR) amplification.

Main results and the role of chance

One hundred and fifty-two AZF microdeletions (11.1%) were detected in the azoospermic patients. The most common deleted region was AZFc (60 cases, 4.4%). Among the patients, 17 (1.2%), 1 (0.1%), 42 (3.1%), 13 (1.0%), and 6 (0.5%) had AZFa, AZFa+b, AZFb+c, AZFb, and AZFa+b+c microdeletions, respectively. When the cases were grouped according to causes of infertility that could be detected, no Y chromosome microdeletions were detected in some groups (cases with Klinefelter Syndrome, hypogonadotropic hypogonadism, congenital absence of vas deferens, and 47, XYY karyotype). Fifty-three azoospermic men with AZFc microdeletions underwent micro TESE, and spermatozoa were detected in 88.7% (47/53) of these men. In contrast, we detected spermatozoa in only 20.4% (109/534) of the azoospermic men without AZF microdeletions. The SRR was much higher in patients with AZFc microdeletions than that of patients without AZF deletions. Although three azoospermic men with AZFb+c microdeletions had also undergone micro TESE following patient request, we did not retrieve spermatozoa.

Limitations, reasons for caution

We excluded post chemotherapy NOA showing 46, XX and AZFa+b+c deletions post bone marrow transplantation from female donor. Additionally, we did not detect AZFc partial deletion including gr/gr deletion. The cohort size of this study is not small, however, our screened population of infertile men may be biased.

Wider implications of the findings

NOA patients with AZFc microdeletions had a high percentage of successful sperm retrieval by micro TESE. Our study emphasizes that diagnosis of Y chromosome microdeletions is critical for preconception genetic counseling and provides clinically valuable prognostic information to couples considering surgical sperm retrieval.

Trial registration number

None

O-130 Reproductive outcomes of normal ovarian reserve patients after progestin-primed ovarian stimulation with chlormadinone acetate vs GnRH antagonist: A retrospective study with inverse-probability-of-treatment weighting

Study question

To evaluate the effectiveness of chlormadinone acetate (CMA) for preventing premature LH surge in patients with normal ovarian reserve compared to cetrorelix.

Summary answer

In progestin-primed ovarian stimulation (PPOS) than GnRH antagonist (GnRH-ant), the incidence of premature LH surge was significantly lower, without significant difference in oocyte maturation rate.

What is known already

The GnRH-ant protocol is one of the conventional protocols which has some disadvantages including increased premature LH surge rate and cancelation rate. In recent years, the PPOS protocol has attracted attention as a new ovarian stimulation using progestin as an alternative to GnRH analog for suppressing a premature LH surge, however its efficacy is still controversial. In addition, many studies have investigated the reproductive outcomes of PPOS using medroxy-progesterone acetate or dydrogesterone; however, there are few reports of CMA, an oral progestin, which is inexpensive and widely used in Japan.

Study design, size, duration

This retrospective cohort study was performed in a reproduction center between March 2018 and October 2020 which included 977 Japanese patients with normal ovarian reserve undergoing PPOS with CMA (n = 299), or GnRH antagonist (GnRH-ant) with cetrorelix (n = 608) in their first IVF cycle at the reproduction center. In subgroup analysis, pregnancy outcomes after frozen embryo transfers (FET) between PPOS (n = 284) and GnRH-ant (n = 579) were also compared.

Participants/materials, setting, methods

The inclusion criteria were patients aged &lt; 40 years and AMH ≧ 1.1 ng/mL, who underwent autologous oocyte retrieval in their first IVF cycle with freeze-all strategy. The primary outcome was the incidence of premature LH surge, the secondary outcomes was oocyte maturation rate. To reduce the impact of treatment bias and potential confounding factors, we conducted logistic regression models with inverse-probability-of-treatment weighting (IPTW).

Main results and the role of chance

After IPTW, baseline clinical data were well-balanced between the two groups, including age, AMH, BMI, the duration, type, and cause of infertility, antral follicle count, the history of recurrent spontaneous abortion, and previous IVF attempts. The premature LH surge rate was significantly lower with PPOS (3.1%) compared to GnRH-ant (20.1%) (odds ratio, 0.21; 95% confidence interval, 0.11–0.36). No significant differences were found in total gonadotropin dose (2400IU for PPOS vs 2400IU for GnRH-ant, p = 0.136), the number of oocyte retrieval (n = 15 vs n = 15, p = 0.484), oocyte maturation rate (78.8% vs 77.8%, p = 0.275), fertilization rate (73.0% vs 72.0%, p = 0.412), viable embryo rate per oocyte retrieval (40% vs 40%, p = 0.890), and good quality blastocyst rate (72.0% vs 69.6%, p = 0.092). However, the good quality day-3 embryo rate was significantly lower with PPOS (37.2% vs 49.1%, p &lt; 0.05). There were no differences in the incidence of moderate-to-severe OHSS (0.3% vs 0.7%, p = 0.481). In FET cycles, the pregnancy outcomes, such as implantation rate (43.1 % vs 51.9 %, p = 0.013) and clinical pregnancy rate (46.5% vs 54.7%, p = 0.027) were significantly lower with PPOS, however, no significant differences were found in ongoing pregnancy rate (75.6% vs 80.5%, p = 0.325), and live birth rate (72.4% vs 79.5 %, p = 0.142).

Limitations, reasons for caution

This was a retrospective cohort study conducted in a single center. The participants in this study were limited to Japanese ethnicity. The results need to be validated across different centers and other ethnicities.

Wider implications of the findings

This is the first report assessing the reproductive outcomes on PPOS using CMA, widely used in Japan. The PPOS with CMA significantly suppressed the premature LH surge rate compared to GnRH-ant protocol, without decrease in oocyte maturation rate.

Trial registration number

N/A

Biliary obstruction and pancreatitis after duodenal stent placement in the descending duodenum: a retrospective study

BACKGROUND

Metallic stents placed in the descending duodenum can cause compression of the major duodenal papilla, resulting in biliary obstruction and pancreatitis. These are notable early adverse events of duodenal stent placement; however, they have been rarely examined. This study aimed to assess the incidence of and risk factors for biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum.

METHODS

We retrospectively reviewed data of consecutive patients who underwent metallic stent placement in the descending duodenum for malignant gastric outlet obstruction at a tertiary referral cancer center between April 2014 and December 2019. Risk factors for biliary obstruction and/or pancreatitis were analyzed using a logistic regression model.

RESULTS

Sixty-five patients were included. Biliary obstruction and/or pancreatitis occurred in 12 patients (18%): 8 with biliary obstruction, 2 with pancreatitis, and 2 with both biliary obstruction and pancreatitis. Multivariate analysis indicated that female sex (odds ratio: 9.2, 95% confidence interval: 1.4-58.6, P = 0.02), absence of biliary stents (odds ratio: 12.9, 95% confidence interval: 1.8-90.2, P = 0.01), and tumor invasion to the major duodenal papilla (odds ratio: 25.8, 95% confidence interval: 2.0-340.0, P = 0.01) were significant independent risk factors for biliary obstruction and/or pancreatitis.

CONCLUSIONS

The incidence of biliary obstruction and/or pancreatitis after duodenal stent placement in the descending duodenum was non-negligible. Female sex, absence of biliary stents, and tumor invasion to the major duodenal papilla were the primary risk factors. Risk stratification can allow endoscopists to better identify patients at significant risk and permit detailed informed consent.

Needle tract seeding after endoscopic ultrasound-guided tissue acquisition of pancreatic tumors: A nationwide survey in Japan

OBJECTIVES

Endoscopic ultrasound-guided tissue acquisition (EUS-TA) plays a crucial role in the diagnosis of pancreatic tumors. The present study aimed to investigate the current status of needle tract seeding (NTS) after EUS-TA of pancreatic tumors based on a nationwide survey in Japan.

METHODS

Patients who underwent surgical resection of primary pancreatic tumors after EUS-TA performed between April 2010 and March 2018 were surveyed. The incidence rates of NTS were determined, and compared in patients with pancreatic ductal adenocarcinomas (PDACs) and other tumors, and in patients who underwent transgastric and transduodenal EUS-TA of PDACs. The detailed features and prognosis of patients with NTS were also assessed.

RESULTS

A total of 12,109 patients underwent surgical resection of primary pancreatic tumors after EUS-TA. The overall incidence rate of NTS was 0.330%, and the NTS rate was significantly higher in patients with PDAC than in those with other tumors (0.409% vs. 0.071%, P=0.004). NTS was observed in 0.857% of patients who underwent transgastric EUS-TA, but in none of those who underwent transduodenal EUS-TA. Of the patients with NTS of PDACs, the median time from EUS-TA to occurrence of NTS and median patient survival were 19.3 and 44.7 months, respectively, with 97.4% of NTS located in the gastric wall and 65.8% of NTS resected. The patient survival was significantly longer in patients who underwent NTS resection than in those without NTS resection (P=0.037).

CONCLUSIONS

NTS appeared only after transgastric not after transduodenal EUS-TA. Careful follow-up provides an opportunity to remove localized NTS lesions by gastrectomy.

Present status of germline findings in precision medicine for Japanese cancer patients: issues in the current system

OBJECTIVE

Since 2019, precision cancer medicine has been covered by national insurance in Japan; however, to date, germline findings have not been fully reported. The aim of this study was to evaluate the current status and raise a problem of germline finding analysis and disclosure in Japanese precision cancer medicine.

METHODS

Germline findings of 52 genes were examined in 296 cases with advanced cancer by a case series study.

RESULTS

Six (2.0%) cases were examined by the Oncoguide™ NCC Oncopanel with germline testing, but no germline findings were reported. The remaining 290 (98.0%) cases were analyzed by FoundationOne® CDx (tumor-only testing), which recognized 404 pathogenic variants; those of BRCA1/2 were recognized in 16 (5.5%) tumors. Our institutional algorithm suggested 39 candidate germline findings in 34 cases, while the public algorithm listed at least 91 candidate germline findings. Four germline findings had been previously identified (BRCA1: 3 and ATM: 1). Nine of 30 cases with candidate germline findings excluding these known germline findings refused or deferred germline testing. Only 4 of 16 cases that received counseling underwent germline testing, and those 4 revealed 3 germline findings (BRCA2, CDK4 and RAD51C); in total, 8 (2.7%) germline findings were revealed. Reasons for refusing genetic counseling and/or germline testing included extra hospital visits, added expense for germline testing due to limited national insurance coverage, poor patient physical condition and no known family members associated with the possible germline finding.

CONCLUSIONS

In current Japanese precision cancer medicine, only a small fraction of the patients undergoes germline testing and demonstrated germline finding. The current results suggested a need for earlier indications for precision cancer medicine, broader insurance coverage and more efficient germline finding prediction algorithms, to increase the number of germline testings and to improve the following managements.

Endoscopic submucosal dissection versus surgery in elderly patients with early gastric cancer of relative indication for endoscopic resection

OBJECTIVES

Surgery is recommended for early gastric cancer (EGC) beyond the endoscopic resection (ER)-indication for the risk of lymph node metastasis; however, ER may be chosen as a "relative ER-indication" considering age and comorbidities. This study aimed to compare outcomes of endoscopic submucosal dissection (ESD) only and surgery (primary surgery and additional surgery after non-curative ESD) among elderly patients with relative ER-indication EGC and to further assess prognostic factors.

METHODS

Outcomes of ESD and surgery (417 cases; 114 ESD, 303 surgery) in elderly patients (≥75 years) with relative ER-indication EGC were retrospectively analyzed. Prognostic factors were also examined.

RESULTS

During the observation period (median; ESD, 34 months; surgery, 61 months), 29% of ESD and 35% of surgery patients died, including 4% and 5% from gastric cancer (GC), respectively. ESD showed lower overall survival (OS) than surgery (P = 0.027) but comparable disease-free survival (P = 0.916). OS-associated factors were age and prognostic nutritional index (PNI) in males (age ≥79, hazard ratio [HR] 2.21, P = 0.001; PNI <45, HR 2.06, P = 0.031) and age in females (age ≥82, HR 4.06, P = 0.004). Treatment was not a prognostic factor in either subgroup. Pathological category ≥pT1b2 (submucosal invasion ≥500 µm) and lymphovascular invasion (LVI) were significantly associated with GC death (mortality: ≥pT1b2, 7.7%, P = 0.002; LVI, 10.1%, P < 0.001).

CONCLUSIONS

In elderly patients with relative ER-indication EGC, ESD may have comparable long-term efficacy to surgery, and treatment selection had a minor contribution to OS. For patients with poor preoperative prognostic factors, diagnostic ESD may be performed first, followed by additional surgery based on pathological results.

Predicting the depth of superficial adenocarcinoma of the esophagogastric junction

BACKGROUND AND AIM

Preoperative determination of the invasion depth of superficial adenocarcinoma of the esophagogastric junction is important for appropriate endoscopic or surgical resection. There are no objective criteria regarding this; therefore, we investigated the factors associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction.

METHODS

This retrospective study evaluated patients with superficial adenocarcinoma of the esophagogastric junction who had undergone endoscopic or surgical resection at a Japanese tertiary cancer center between April 2004 and December 2017. We analyzed endoscopic features of intramucosal to slight submucosal (M-SM1; < 500 μm) and deep submucosal (SM2; ≥ 500 μm) adenocarcinoma of the esophagogastric junction and extracted significant factors associated with and assessed the diagnostic performance of endoscopic features for SM2 lesion.

RESULTS

A total of 106 cases were included in this study. Multivariate analysis indicated that depressed or protruded type (odds ratio [OR], 11.1), lesion size ≥ 15 mm (OR, 3.11), uneven surface (OR, 6.31), and subsquamous extension (OR, 5.41) were significantly associated with SM2 adenocarcinomas of the esophagogastric junction. When the macroscopic type was depressed or protruded, high sensitivity (97%) but fair specificity (46%) were observed for SM2 adenocarcinoma of the esophagogastric junction, whereas uneven surface and subsquamous extension showed high specificity (96% and 87%) but fair sensitivity (36% and 46%).

CONCLUSIONS

Depressed or protruded type, lesion size ≥ 15 mm, uneven surface, and subsquamous extension were significantly associated with the invasion depth of superficial adenocarcinoma of the esophagogastric junction. These endoscopic features are useful in determining the treatment method preoperatively.

Microsatellite instability is biased in Amsterdam II-defined Lynch-related cancer cases with family history but is rare in other cancers: a summary of 1000 analyses

Background

Microsatellite instability (MSI) is a key marker for predicting the response of immune checkpoint inhibitors (ICIs) and for screening Lynch syndrome (LS).

Aim

This study aimed to see the characteristics of cancers with high level of MSI (MSI-H) in genetic medicine and precision medicine.

Methods

This study analyzed the incidence of MSI-H in 1000 cancers and compared according to several clinical and demographic factors.

Results

The incidence of MSI-H was highest in endometrial cancers (26.7%, 20/75), followed by small intestine (20%, 3/15) and colorectal cancers (CRCs)(13.7%, 64/466); the sum of these three cancers (15.6%) was significantly higher than that of other types (2.5%)(P < 0.0001). MSI-H was associated with LS-related cancers (P < 0.0001), younger age (P = 0.009), and family history, but not with smoking, drinking, or serum hepatitis virus markers. In CRC cases, MSI-H was significantly associated with a family history of LS-related cancer (P < 0.0001), Amsterdam II criteria [odds ratio (OR): 5.96], right side CRCs (OR: 4.89), and multiplicity (OR: 3.31). However, MSI-H was very rare in pancreatic (0.6%, 1/162) and biliary cancers (1.6%, 1/64) and was null in 25 familial pancreatic cancers. MSI-H was more recognized in cancers analyzed for genetic counseling (33.3%) than in those for ICI companion diagnostics (3.1%)(P < 0.0001). Even in CRCs, MSI-H was limited to 3.3% when analyzed for drug use.

Conclusions

MSI-H was predominantly recognized in LS-related cancer cases with specific family histories and younger age. MSI-H was limited to a small proportion in precision medicine especially for non-LS-related cancer cases.

Cold snare polypectomy for superficial non-ampullary duodenal epithelial tumor: a prospective clinical trial (pilot study)

BACKGOUND

Cold snare polypectomy (CSP) can minimize the risk of adverse events and has become a standard treatment for small colorectal polyps. CSP might also be suitable for small superficial non-ampullary duodenal epithelial tumors (SNADETs). This study aimed to evaluate the safety of CSP for SNADETs.

METHODS

The major indication criteria were as follows: (1) endoscopically diagnosed SNADET, (2) ≤ 10 mm, and (3) a single primary lesion. CSP was performed using an electrosurgical snare without electrocautery. Follow-up endoscopy and scar biopsy were performed 3 months after CSP. The primary endpoint was the delayed adverse events rate.

RESULTS

In total, 21 patients were enrolled. Two and 19 lesions were located in the duodenal bulb and 2nd portion, respectively; the median lesion size was 8 mm. CSP was attempted for all lesions; three lesions could not be resected without electrocautery and were removed by conventional endoscopic mucosal resection (EMR). The rate of spurting bleeding after CSP was 0%. The median procedure time was 12 min, the median resected specimen size was 12 mm, and the rate of en bloc resection was 81% (17/21). No adverse events were observed intraoperatively, with no delayed adverse events after CSP. Histopathology revealed 15 adenomas, 4 cancers (intramucosal), and 2 non-neoplastic lesions. The horizontal margins were negative/positive/undetermined in 9, 1, and 11 cases, respectively. All vertical margins were negative. Only one recurrence was detected by follow-up endoscopy 3 months after CSP.

CONCLUSIONS

CSP can be performed safely for small SNADETs.

CLINICAL TRIAL REGISTRATION

This trial was registered with the University Hospital Medical Information Network Clinical Trials Registry ( http://www.umin.ac.jp/ctr/index.htm ), and the registration number is UMIN000019157.

Efficacy of endoscopic samplings during initial biliary drainage for cases of pancreatic head cancer: United diagnostic yields of multiple pathological samplings

BACKGROUND/OBJECTIVES

The diagnostic ability of endoscopic ultrasound-guided fine needle aspiration (EUS-FNA) has been fully studied; however, the efficacy of other endoscopic samplings (OESs) is less clear. The aim of this study was to examine the diagnostic efficacies of OESs for pancreatic head cancer (PHC).

METHODS

The diagnostic efficacies of endoscopic samplings were retrospectively analyzed in 448 PHC cases and 63 cases of mass-forming pancreatitis (MFP) during initial transpapillary biliary drainage. The OESs included duodenal biopsy (118 PHCs and 50 MFPs), biliary biopsy (218 and 51) with cytology (368 and 53), and pancreatic duct biopsy (23 and 13) with cytology (56 and 43). EUS-FNA was conducted in a different session (149 and 62). Factors associated with OES sensitivity were analyzed. The sensitivity of biliary biopsy was compared between 1.95 mm and 1.8 mm forceps.

RESULTS

Cancer cells were confirmed in 87.9% of the EUS-FNA samplings and in 64.1% (268/418) obtained by combined OESs (average 1.7 OES types per case): 68.6% by duodenal biopsy, 59.6% by biliary biopsy, 32.6% by biliary cytology, 73.9% by pancreatic duct biopsy, and 33.9% by pancreatic duct cytology. No MFP cases revealed cancer by any sampling. OESs did not increase adverse events. Duodenal stenosis, serum bilirubin, tumor size, and pancreatic juice amounts were associated with OES sensitivity. Biliary biopsy had the same sensitivity with different forceps.

CONCLUSION

EUS-FNA was the most diagnostic protocol; however, OESs can be safely applied during the initial biliary drainage to reduce the demand for EUS-FNA while providing good diagnostic yields.

Features of post-endoscopic submucosal dissection electrocoagulation syndrome for early gastric neoplasm

BACKGROUND AND AIM

Post-endoscopic submucosal dissection electrocoagulation syndrome (PECS) has become a common adverse event after colorectal endoscopic submucosal dissection (ESD) and esophageal ESD. However, little is known about PECS after gastric ESD. Therefore, this study aimed to investigate the clinical features of PECS after gastric ESD.

METHODS

Patients who underwent ESD for gastric cancer or adenoma between January 2016 and December 2017 were retrospectively investigated. PECS was clinically diagnosed based on the presence of upper abdominal pain and localized abdominal tenderness with a temperature of >37.5°C, without perforation. We analyzed the clinical features of PECS.

RESULTS

A total of 637 ESD cases were enrolled; PECS occurred in 32 patients (5.0%), all of whom were diagnosed on postoperative Day 1. Among PECS cases, unplanned prolongation of hospitalization or fasting period was observed in 15 patients (47%). As a result, the median durations of hospitalization and fasting period were significantly longer in PECS cases (P = 0.008 and P < 0.001, respectively); however, the mean differences were less than a day. Additionally, all PECS cases recovered with conservative treatment.

CONCLUSIONS

PECS is considered a common adverse event after gastric ESD. More than half of patients with PECS could start diets and be discharged as well as those without PECS.

Endoloop closure following gastric endoscopic submucosal dissection to prevent delayed bleeding in patients receiving antithrombotic therapy

OBJECTIVES

Given the high risk of bleeding in post-endoscopic submucosal dissection (ESD) patients receiving antithrombotic therapy, a new effective method is needed to prevent delayed bleeding among such patients. The aim of this study was to assess the efficacy of endoloop closure, using an endoloop and clips, after gastric ESD to prevent bleeding among patients receiving antithrombotic therapy.

METHODS

This retrospective study enrolled patients taking antithrombotic agents who underwent ESD for early gastric cancer between March 2016 and January 2019. Patients were classified into two groups: the endoloop closure group and the control group (no prophylactic treatment). We compared the rates of post-endoscopic submucosal dissection bleeding between the two groups.

RESULTS

Overall, 178 patients were included, with 37 patients in the endoloop closure group and 141 patients in the control group. The rate of post-endoscopic submucosal dissection bleeding was in general lower in the endoloop closure group than in the control group; however, the difference was not statistically significant (8% vs. 23%, p = 0.06). Among patients with a resected specimen size <40 mm and those using multiple antithrombotic agents, the endoloop closure group showed a lower rate of post-endoscopic submucosal dissection bleeding (0% vs. 16%, p = 0.03 and 10% vs. 70%, p = 0.02, respectively).

CONCLUSIONS

Closure using an endoloop and endoclips after gastric ESD might prevent post-procedure bleeding in patients receiving antithrombotic therapy, particularly in those patients with a resected specimen <40 mm and those receiving multiple antithrombotic agents.

P–032 Assessment of embryonic developmental outcome of direct unequal cleavage in patients with non-obstructive azoospermia and/or obstructive azoospermia

Study question

Does direct unequal cleavage (DC) affect embryonic development after ICSI with testicular sperm (TESE-ICSI) in patients with non-obstructive azoospermia (NOA) and/or obstructive azoospermia (OA)?

Summary answer

The incidence of DC at the first cleavage (DC1) was extremely high and DC1 negatively affected embryonic development in NOA patients.

What is known already

It has been reported that the blastocyst development of embryos with direct cleavage (DC) was significantly lower than that without DC, but the clinical pregnancy rate after blastocyst transfer was not different with or without DC. The incidence of DC has been reported to be significantly higher after ICSI with testicular sperm (TESE-ICSI) than ICSI with ejaculated sperm (Ej), but to our knowledge, there are few reports investigating that the embryos with DC after TESE-ICSI affect embryonic development.

Study design, size, duration

We conducted a retrospective cohort study using time-lapse incubators (Geri, Genea Biomedx, Australia) from September 2018 to November 2020. Of 1033 two-pronuclear (2PN) embryos from TESE-ICSI, 486 and 547 embryos were from OA (35.9±5.5 years) and NOA (33.7±5.2 years), respectively. As an age matched control, we chose 581 embryos from ICSI using Ej (36.5±4.4 years).

Participants/materials, setting, methods

DC embryos were classified as DC1 (DC at first cleavage), DC2 (DC at second cleavage), and non-DC (without DC). The incidences of DC1 or DC2 and blastocyst development rates were compared among OA, NOA and Ej groups. In TESE-ICSI group, we compared blastocyst development rates with or without DC between good and poor quality embryos on day 3. Good quality embryos were defined as 8 cells with G3 or more by the Veeck’s classification.

Main results and the role of chance

DC1 incidence was significantly higher in NOA (37.3%) than OA (27.8%) and Ej (22.7%) (P &lt; 0.01), whereas DC2 incidence was not statistically different among three groups; NOA (15.7%), OA (15.0%) and Ej (13.4%). Blastocyst development rates in DC1 were 17.8%, 19.5% and 25.8% for NOA, OA and Ej, respectively, which were significantly lower compared to non-DC in corresponding three groups (65.1%, 67.7%, and 68.5%, respectively, P &lt; 0.01). In TESE-ICSI group, good-quality embryo rate on day 3 was significantly lower in DC1 (34.5%, P &lt; 0.01) than DC2 (60.9%) or non-DC (54.2%). Additionally, blastocyst development rates in DC1 and DC2 were significantly lower than non-DC regardless of embryonic grades on day 3 (35.1%, 51.0%, and 81.6% for good-quality embryos on day 3, 10.1%, 27.0%, and 49.1% for poor-quality embryos on day 3, respectively, P &lt; 0.05). When immotile sperm was used for TESE-ICSI, DC1 incidence was 40.0% (6/15), which did not show statistically differences. When performing single frozen-thawed blastocyst transfers, no pregnancies resulted from either DC1 (n = 13) or DC2 (n = 3) embryos in TESE-ICSI group.

Limitations, reasons for caution

We had a few data about the pregnancy rates after blastocyst transfers with DC, because embryos with DC were seldom transferred due to those lower priority. Although DC might be influenced by the sperm, we did not analyze the incidence of DC by taking the semen factors into account.

Wider implications of the findings: The incidence of DC1 was extremely high and DC1 negatively affected embryonic development in NOA patients. Therefore, it is important to observe embryos using time-lapse incubator in order to recognize embryos with/without pregnancy potential, especially for embryos with DC1 in NOA patients.

Trial registration number

Not applicable

P–019 Sperm parameter and ICSI / IVF outcomes after sperm selection using microfluidic sperm separator and density gradient centrifugation with swim-up in split semen sample

Study question

To analyze whether microfluidic sperm selection (MSS) by ZyMōt™ improves sperm DNA fragmentation rate and embryonic development compared to density gradient centrifugation with swim-up (DGCS).

Summary answer

MSS by ZyMōt™ selects sperm for clinical use with less DNA damage significantly compared to DGCS.

What is known already

Conventional sperm preparation methods, such as density gradient centrifugation and the swim-up method utilize centrifugation during processing, may damage the sperm. MSS may allow for improved selection of normal sperm compared with conventional sperm preparation as it yields sperm with a lower DNA fragmentation rate. However, there are few clinical studies by sibling oocytes study compared to DGCS.

Study design, size, duration

This prospective study was performed between March 2020 and May 2020 at a reproductive center. All patients involved gave written consent, and institutional review board approval was granted. A total of 575 metaphase II oocytes were collected from 49 cycles. Wife’s age was 34.7 ± 3.9 years old. Raw sperm concentration and motile sperm concentration was 63.1 ± 78.7M/mL, and 41.6 ± 67.7M/mL, respectively.

Participants/materials, setting, methods

Patients who performed ART for the first or second time were divided into two groups according to MSS and DGCS. Sperm DNA fragmentation rate (SDFR) and motile sperm concentration were compered between MSS and DGCS. SDFR was measured by sperm chromatin structure assay (SCSA) using a flow cytometer. Sibling oocytes were randomized into MSS-IVF, DGCS-IVF, MSS-ICSI, and DGCS-ICSI. Rate of two pronuclear (2PN) oocytes, blastocysts development, and good-quality blastocysts were compared between each group.

Main results and the role of chance

SDFR was 13.5 ± 11.8% for raw semen. SDFR was significantly lower after MSS (3.6 ± 4.1%) than that for raw semen and after DGCS (17.4 ± 14.8%) (P &lt; 0.01). Motile sperm concentration after MSS (19.0 ± 28.3M/mL) was significantly higher after than after DGCS (15.4 ± 15.3M/mL) (P &lt; 0.01). The number of IVF performed was 145 for MSS and 132 for DGCS. IVF results (MSS vs DGCS) were 2PN rate (73.1% vs 72.0%), blastocysts development rate (65.3% vs 55.4%), and good quality blastocysts rate (43.2% vs 34.9%). The number of ICSI performed was 149 for MSS and 149 for DGCS. ICSI results (MSS vs DGCS) were 2PN rate (77.9% vs 79.2%), blastocysts development rate (68.8% vs 65.8%), and good quality blastocysts rate (35.8% vs 30.6%). No significant difference was observed between MSS and DGCS for each parameter both IVF and ICSI.

Limitations, reasons for caution

The participants were limited to those who collected semen of 2mL or more and motile sperm concentration of above 1M/mL, because semen sample needed to be divided to MSS and DGCS.

Wider implications of the findings: This is the first study to conducted in sibling oosytes study with MSS and DGCS, in both IVF and ICSI. MSS is effective in collecting sperm with less DNA damage compared to DGCS. Motile sperm concentration after using MSS is sufficient to perform IVF as well as DGCS.

Trial registration number

Not applicable

Sharing genetic test results of germline pathogenic variants of hereditary cancer with relatives: A single-center cross-sectional study

Objective

This study aimed to determine whether Japanese cancer patients share test results of germline pathogenic variants of hereditary cancer with their relatives.

Methods

This single-center cross-sectional study enrolled 21 Japanese patients who received results of germline pathogenic variants of hereditary cancer at least 6 months prior.

Results

All patients shared their test results with at least one relative, with the following sharing rates: 85.7% for first-degree relatives, 10% for second-degree relatives and 8.3% for third-degree relatives. Patients most commonly shared the information with their children aged >18 years (86.7%), followed by their siblings (73.6%), spouses (64.7%) and parents (54.5%). Three categories were extracted from qualitative analysis: ‘characteristics of my cancer’, ‘knowledge and caution about inheritability’ and ‘utilization of medical care.’

Conclusions

The rate of test result sharing with first-degree relatives was comparable with those in Europe and the USA. Patients with germline pathogenic variants also tended to share their test results more with their children and siblings than with their parents. Informing their relatives of the results was suggestive of the motivation to influence their relatives’ health outcome and contribute to the well-being of their children and siblings.

Long-term outcomes of salvage endoscopic submucosal dissection for local failure after chemoradiotherapy for esophageal squamous cell carcinoma

BACKGROUND

Salvage endoscopic submucosal dissection is considered a minimally invasive treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma. However, the long-term outcomes have not been fully evaluated. This study investigated the short-term and long-term outcomes of salvage endoscopic submucosal dissection.

METHODS

Patients who underwent endoscopic submucosal dissection for local recurrence or residual tumor after chemoradiotherapy from January 2006 to December 2017 were retrospectively investigated. Follow-up included endoscopic examination and computed tomography at least once every 6 months after salvage endoscopic submucosal dissection. Risk factors for disease recurrence after salvage endoscopic submucosal dissection were assessed using the Cox hazards model.

RESULTS

A total of 30 patients (33 cases of esophageal squamous cell carcinoma: local recurrence, n = 27; residual tumor, n = 6) were included. The median endoscopic submucosal dissection procedure time was 40 min (interquartile range [IQR], 33-58.5 min). En bloc resection was achieved in 31 (94%) of 33 esophageal squamous cell carcinoma cases. One patient with intraoperative perforation did not require surgical intervention and recovered with conservative treatment. A total of 16 patients (53%) had disease recurrence at a median follow-up of 51 months (IQR, 33-81 months). The 3-year overall, disease-specific, recurrence-free and local recurrence-free survival rates were 75%, 82%, 58% and 90%, respectively. The positive vertical margin, submucosal invasion in the endoscopic submucosal dissection specimen and piecemeal resection were significantly associated with disease recurrence after salvage endoscopic submucosal dissection.

CONCLUSIONS

Salvage endoscopic submucosal dissection is a feasible treatment for local failure after chemoradiotherapy for esophageal squamous cell carcinoma with acceptable long-term outcomes. However, for cases with positive vertical margins and submucosal invasion in the endoscopic submucosal dissection specimen, salvage endoscopic submucosal dissection outcomes were insufficient and additional treatment might be required.

Can regular follow-up imaging contribute to the determination of appropriate timing of surgery in patients with undiagnosed mucinous cystic neoplasm? A multicenter retrospective study

OBJECTIVE

Guidelines suggest that patients with undiagnosed pancreatic cystic lesions should be monitored despite a lack of evidence supporting surveillance for undiagnosed mucinous cystic neoplasms (MCNs). We aimed to investigate the pre- and post-operative clinical course of patients with MCN and the utility of follow-up for patients who were not diagnosed with MCN at initial examination.

PATIENTS AND METHODS

This multicenter retrospective study enrolled 28 patients with resected pathology-proven MCN; 12 and 16 patients underwent surgery within and after 6 months from the initial examination (Groups A and B, respectively). Outcome measures included changes in imaging findings until surgery in Group B, pathological findings between both groups and differences in pathological findings between patients with and without regular follow-up imaging in Group B.

RESULTS

In Group B, the median cyst size was 30 and 48 mm at the initial examination and immediately before surgery, respectively. The incidence of mural cysts, thickened walls and mural nodules were 25, 19 and 0%, respectively, at the initial examination and 69, 56 and 31%, respectively, immediately before surgery. There were no significant differences in the invasive carcinoma rates between Groups A and B (13 vs. 17%). Regular follow-up imaging was offered to Group B. Among these, invasive carcinoma was found in one patient exhibiting no recurrence. One patient without follow-up imaging had invasive carcinoma recurrence post-operatively.

CONCLUSIONS

MCNs increased in size, and typical imaging findings appeared over time. For undiagnosed MCN, regular follow-up examination contributed to the determination of the appropriate surgical timing.

Discrepancy between endoscopic and pathological ulcerative findings in clinical intramucosal early gastric cancer

BACKGROUND

Ulcerative finding (UL) is one of the factors that define the indication and curability of endoscopic resection (ER) in early gastric cancer (EGC). Discrepancies between endoscopic UL (cUL) and pathological UL (pUL) sometimes occur in clinical practice. The aim of this study was to investigate the discrepancy rate in UL diagnosis and the risk factors associated with such discrepancies.

METHODS

Patients with clinical intramucosal (cT1a) EGC who underwent ER or surgery between September 2002 and December 2017 were analyzed. The proportion of cUL-negative (cUL0) lesions that were identified as pUL-positive (pUL1) and that of cUL-positive (cUL1) lesions that were identified as pUL-negative (pUL0) were calculated. Logistic regression analysis was performed to estimate the associations between discrepancy in UL diagnosis and clinical variables of the lesion, such as the size, histology, location, and macroscopic type.

RESULTS

In total, 5382 lesions were evaluated; 5.5% of cUL0 lesions (256/4619) were identified as pUL1, while 38.7% of cUL1 lesions (295/763) were pUL0. Multivariate analysis indicated that in cUL1 lesions, tumor location in the lower third of the stomach (odds ratio 3.11, 95% confidence interval 1.90-5.08) was identified as an independent risk factor for overestimation.

CONCLUSIONS

Endoscopic diagnosis of UL in cT1a EGC was overestimated in 38.7% of lesions, especially for lesions located in the lower third of the stomach. This discrepancy should be considered in the management of cT1a EGC with UL.

Ultrathin colonoscopy can improve complete preoperative colonoscopy for stenotic colorectal cancer: Prospective observational study

OBJECTIVES

Preoperative colonoscopy is often incomplete for stenotic colorectal cancers (CRC). This prospective observational study aimed to evaluate the ability of an ultrathin colonoscope (UTC) to inspect the whole colon by passing through the stenotic CRC.

METHODS

All patients who underwent preoperative colonoscopy for stenotic CRCs at Shizuoka Cancer Center were examined for eligibility. If a standard colonoscope (PCF-H290ZI) could not pass because of a stenosis, the patients were recruited. All of the eligible patients were prospectively enrolled when informed consent could be obtained, and complete colonoscopy was attempted again using an UTC (PCF-PQ260L). Patients with stent placement and those requiring right hemicolectomy were not recruited. Primary endpoints were pass-through and cecal intubation rates. The detected synchronous neoplasias (adenomas and cancers) and their pathological findings after resection were evaluated.

RESULTS

A total of 100 patients were enrolled between September 2017 and February 2019. The mean age was 65.6 ± 10.8 years, and 59% were male. The pass-through and cecal intubation rates were 67% (67/100) and 58% (58/100), respectively. Synchronous lesions located proximal to the stenoses were detected in 65.5% (38/58) of the complete colonoscopies, with a total of 86 lesions, including 18 advanced neoplasias with three invasive cancers.

CONCLUSION

When standard colonoscopy cannot pass through stenotic CRC, ultrathin colonoscopy can be considered as an option to inspect the whole colon proximal to the stenosis because treatment strategy can potentially be changed by detecting synchronous neoplasias proximal to the stenosis before surgery. (UMIN000028505).

Genomic profiling of multiple tissues in two patients with multiple endocrine neoplasia type 1

Multiple endocrine neoplasia type 1 (MEN1) is an autosomal dominant tumor syndrome. This hereditary cancer is caused by germline variants in MEN1. Two patients with MEN1 were identified via whole exome sequencing and gene expression profile analysis, conducted for 5,063 patients with various types of cancers. We obtained multiple tumors from each patient; tumors derived from these two MEN1 patients had a loss of the normal MEN1 allele and frequently chromosomal copy number changes. Thus, we investigated whether structural variants were present in the MEN1 patient genomes. Whole-genome sequencing revealed no catastrophic rearrangements, and the tumor samples had very low somatic variants. The two patients had germline variants in MEN1 and some chromosomal copy number changes including on chromosome 11. The only pathogenic variant detected was the MEN1 germline variant, and chromosomal rearrangements led to tumorigenesis in somatic cells. Furthermore, the MEN1 tumor samples displayed a specific signature characterized by T:A>C:G transition. Studies of multiple tumors obtained from single patients are rare in hereditary cancer syndromes, and our results provide insights that the second hit of the tumor suppressor gene MEN1 may be caused by a gross genome rearrangement, not a small insertion and deletion, nor a change in epigenetic regulation.

Comparison of five-phase computed tomography images of type 1 autoimmune pancreatitis and pancreatic cancer: Emphasis on cases with atypical images

BACKGROUND/OBJECTIVES

International consensus diagnostic criteria (ICDC) include characteristic images of autoimmune pancreatitis (AIP); however, reports on atypical cases are increasing. The aims of this study were to compare CT findings between AIP and pancreatic cancer (PC), and to analyze type 1 AIPs showing atypical images.

METHODS

Five-phase CT images were compared between 80 type 1-AIP lesions and 80 size- and location-matched PCs in the case-control study. Atypical AIPs were diagnosed based on the four ICDC items.

RESULTS

ICDC items were recognized in most AIP lesions; pancreatic enlargement (87.7%), narrowing of the main pancreatic duct (98.8%), delayed enhancement (100%), and no marked upstream-duct dilation (97.5%). CT values of AIPs increased rapidly until the pancreatic phase and decreased afterward, while those of PCs gradually increased until the delayed phase (P < 0.0001). Atypical images were recognized in 14.8% of AIPs, commonly without pancreatic enlargement (18.5 mm) and sometimes mimicking intraductal neoplasms. The CT values and their ratios were different between atypical AIPs and size-matched PCs most significantly in the pancreatic phase, but similar in the delayed phase.

CONCLUSIONS

Ordinary type 1 AIPs can be diagnosed with the ICDC, but atypical AIPs represented a small fraction. "Delayed enhancement" is characteristic to ordinary AIPs, however, "pancreatic-phase enhancement" is more diagnostic for atypical AIPs.

Effectiveness of suction valve button removal in retrieving resected colon polyps for better histological assessment: Propensity score matching analysis

BACKGROUND AND AIM

Fragmentation of endoscopically resected colorectal polyps during retrieval is one of the limitations for appropriate pathological diagnosis; however, little is known about steps to reduce it. We aimed to evaluate the effect of removing the suction valve button, which is one of the intricate parts of the endoscope, during polyp suction retrieval for fragmentation and pathological diagnosis.

METHODS

We retrospectively reviewed the polyps retrieved by suctioning. We used the propensity score matching method to adjust for difference between the button-attached and button-removed groups. Outcomes of fragmentation, pathological diagnosis of non-neoplastic polypectomy (NNP), and pathological cut-end among neoplastic lesions were evaluated.

RESULTS

On the basis of propensity score matching, 322 pairs of cases were selected for analysis. After matching, the difference in the variables between the two groups was closely balanced. The fragmentation rate was significantly different between the groups (button-attached 36.6% vs. button-removed 22.4%, P < 0.001). No significant difference in the NNP rate was observed between the two groups (button-attached 8.4% vs. button-removed 9.9%). The rate of unclear cut-end was lower in the button-removed group than in the button-attached group (16.2% vs. 9.1%, P = 0.010). In the multivariate analysis, button removal was independently associated with reductions of fragmentation (odds ratio [OR] 0.508, P < 0.001) and unclear cut-end (OR 0.503, P = 0.009). Also, NNP was associated with smaller lesion size (OR 0.364, P < 0.001), but not with button removal.

CONCLUSIONS

Suction valve button removal during polyp suction retrieval was an effective method to decrease the rates of fragmentation and histological unclear margins.

Type 1 Autoimmune Pancreatitis Extending along the Main Pancreatic Duct: IgG4-related Pancreatic Periductitis

We herein report a unique form of autoimmune pancreatitis (AIP) spreading along the main pancreatic duct (MPD). A 70-year-old man was referred for a small lesion at the pancreatic neck, accompanying an adjacent cyst and dilated upstream MPD. Four years earlier, health checkup images had shown a pancreatic cyst but no mass lesion. Endoscopic ultrasonography showed a contrast-enhanced, tumorous lesion, mainly occupying the MPD. With a preoperative diagnosis of ductal neoplasms mainly spreading in the MPD, Whipple's resection was performed. The resected specimens showed MPD periductitis with IgG4-related pathology, indicating type 1 AIP. Clinicians should practice caution concerning the various AIP forms.