Spontaneous disappearance of common bile duct stones following the insertion of a new dumbbell-shaped, covered self-expandable metallic stent in a patient with benign biliary stricture

The new dumbbell-shaped, covered self-expanding metallic stent can efficiently remove the choledocholiths in cases with common bile duct (CBD) strictures; moreover, it may potentially prevent a positional displacement and contribute to the better improvement of the CBD stricture.

Localized gastric amyloidosis diagnosed by endoscopic ultrasound-guided fine-needle aspiration

A 49-year-old man was found to have an elevated lesion on esophagogastroduodenoscopy (EGD) for gastric cancer screening. This lesion had been noted in EGD 13 years earlier, but the patient had not received EGD since then. Endoscopy showed a relatively soft subepithelial lesion (SEL) in the gastric antrum. In addition, endoscopic ultrasonography (EUS) showed a 20-mm-sized, slightly non-uniform hypoechoic mass in the submucosa. Since the diagnosis could not be confirmed by mucosal biopsy, EUS-guided fine-needle aspiration (EUS-FNA) was performed. Hematoxylin-eosin staining of EUS-FNA samples revealed deposition of acidophilic unstructured materials. The structure was positive on Congo red staining, and green polarized light was also observed under a polarizing microscope. Moreover, it was resistant to potassium permanganate reaction, negative for serum amyloid A protein, positive for anti-λ chain antibody, and negative for anti-κ chain, anti-amyloid A, anti-transthyretin, and anti-β2-microglobulin antibodies. Therefore, the lesion was diagnosed as AL-λ-type amyloidosis. No systemic amyloidosis findings were found; thus, the patient was finally diagnosed with localized gastric AL amyloidosis. If an SEL is seen without disease-specific endoscopic findings, amyloidosis should be included in the differential diagnosis, and EUS-FNA can contribute to obtaining tissue samples in such cases.

A simple method for diagnosing gallbladder malignant tumors with subserosa invasion by endoscopic ultrasonography

BACKGROUND

If the depth of gallbladder malignant tumor (GBMT) invasion is deeper than the subserosa (ss), cholecystectomy is insufficient. In past reports that used endoscopic ultrasonography (EUS) to diagnose the depth of tumor invasion, it was difficult to diagnose GMBT invasion in the ss without a narrow or disrupted lateral hyperechoic layer (LHEL). Therefore, we developed a simple preoperative method to diagnose GBMTs with ss invasion.

METHODS

Forty-nine GBMT patients who underwent both EUS and surgery were enrolled: 15 patients whose tumors invaded the mucosa (m) or muscularis propria (mp) were classified as the "shallow group", and 34 patients whose tumors invaded the ss were classified as the "deep group". The EUS findings were compared between the two groups.

RESULTS

An irregular (narrow or thickened) LHEL was significantly more frequently observed on EUS in the deep group than in the shallow group. The diagnosis of ss invasion based on an irregular LHEL had the highest sensitivity and accuracy among the EUS imaging parameters (sensitivity 97.1% (33/34), specificity 86.7% (13/15), accuracy 93.8% (46/49)). When the deep group was limited to patients with a tumor depth of ss, the results were similar. When an irregular LHEL was used, the diagnostic accuracy of GBMTs with ss invasion was not significantly different between EUS specialists and beginners.

CONCLUSIONS

The observation of an irregular (thickened or narrow) LHEL observed on EUS could be a reliable and simple method of diagnosing GBMTs with ss invasion and could contribute to choosing an appropriate surgical method.

The Dramatic Haemostatic Effect of Covered Self-expandable Metallic Stents for Duodenal and Biliary Bleeding

Bilio-duodenal bleeding, such as post-endoscopic sphincterotomy (EST) bleeding, common bile duct (CBD) bleeding after endoscopic retrograde cholangiopancreatography (ERCP), and duodenal bleeding due to malignant tumour invasion, can sometimes become severe. Six cases of refractory bilio-duodenal bleeding were stanched via covered self-expandable metallic stent (CSEMS) insertion, even though three of the patients had a history of gastrectomy. The dumbbell-shaped CSEMS was useful for managing post-EST bleeding. Additional duodenal CSEMS insertion was useful for the patient who had previously undergone uncovered SEMS insertion, and no migration of the CSEMS was observed. CSEMS insertion was useful for treating refractory bilio-duodenal haemorrhaging.

Prevention of Stricture after Endoscopic Submucosal Dissection for Superficial Esophageal Cancer: A Review of the Literature

Endoscopic resection has been the standard treatment for intramucosal esophageal cancers (ECs) because of the low risk of lymph node metastases in the lesions. In recent years, endoscopic submucosal dissection (ESD), which can resect large ECs, has been performed. However, the risk of esophageal stricture after ESD is high when the mucosal defect caused by the treatment exceeds 3/4 of the circumference of the lumen. Despite the subsequent high risk of luminal stricture, ESD has been performed even in cases of circumferential EC. In such cases, it is necessary to take measures to prevent stricture. Therefore, in this review, we aimed to clarify the current status of stricture prevention methods after esophageal ESD based on previous literature. Although various prophylactic methods have been reported to have stricture-preventing effects, steroid injection therapy and oral steroid administration are mainstream. However, in cases of circumferential EC, both steroid injection therapy and oral steroid administration cannot effectively prevent luminal stricture. To solve this issue, clinical applications, such as tissue shielding methods with polyglycolic acid sheet, autologous oral mucosal epithelial sheet transplantation, and stent placement, have been developed. However, effective prophylaxis of post-ESD mucosal defects of the esophagus is still unclear. Therefore, further studies in this research field are needed.

Efficacy of EUS-guided FNB using a Franseen needle for tissue acquisition and microsatellite instability evaluation in unresectable pancreatic lesions

Background

The efficacy of immune checkpoint blockade in the treatment of microsatellite instability (MSI)-high tumors was recently reported. Therefore, the acquisition of histological specimens is desired in cases of unresectable solid pancreatic lesions (UR SPLs). This study investigated the efficacy of endoscopic ultrasound-guided fine-needle biopsy (EUS-FNB) using a Franseen needle for UR SPL tissue acquisition and MSI evaluation.

Methods

A total of 195 SPL patients who underwent EUS-guided fine-needle aspiration (EUS-FNA) or EUS-FNB (EUS-FNAB) between January 2017 and March 2020 were enrolled in this study. Among them, 89 SPL patients (FNB: 28, FNA: 61) underwent EUS-FNAB using a 22-G needle (UR SPLs: 58, FNB: 22, FNA: 36) (UR SPLs after starting MSI evaluation: 23, FNB: 9, FNA: 14).

Results

The puncture number was significantly lower with FNB than with FNA (median (range): 3 (2–5) vs 4 (1–8), P <  0.01, UR SPLs: 3 (2–5) vs 4 (1–8), P = 0.036). Histological specimen acquisition was more commonly achieved with FNB than with FNA (92.9% (26/28) vs 68.9% (42/61), P = 0.015, UR SPLs: 100% (22/22) vs 72.2% (26/36), P <  0.01). The histological specimen required for MSI evaluation was acquired more often with FNB than with FNA (88.9% (8/9) vs 35.7% (5/14), P = 0.03).

Conclusions

EUS-FNB using a Franseen needle is efficient for histological specimen acquisition and sampling the required amount of specimen for MSI evaluation in UR SPL patients.

Clinical utility of a newly developed microfluidic device for detecting circulating tumor cells in the blood of patients with pancreatico-biliary malignancies

BACKGROUND

The development of an optimal screening method is required to improve the prognosis of pancreatico-biliary (PB) cancers. A recently developed microfluidic device achieved a high diagnostic yield by detecting circulating tumor cells (CTCs) in the blood of cancer patients. We conducted this study to investigate the clinical utility of measuring CTCs in peripheral venous blood to diagnose PB cancer.

METHODS

Sixty-three subjects were enrolled in this study (29 with pancreatic cancer [PC], 19 with biliary cancer [BC] and 16 non-tumor controls). Using a microfluidic chip device and image analyzer, circulating blood cells were selected based on their size and immunocytochemistry staining pattern. The primary endpoint was the diagnostic accuracy of CTCs with regard to distinguishing between PB cancer patients and controls. We divided all cases into the training set (n = 32) and validation set (n = 31). The diagnostic accuracy of CTCs, carcinoembryonic antigen (CEA) and cancer antigen 19-9 (CA19-9) were analyzed.

RESULTS

In both the training set and validation set, CTCs showed the highest diagnostic accuracy (training set: CTCs 90.6%, CA19-9 90.6%, CEA 65.6%, validation set: CTCs 87.5%, CA19-9 78.1%, CEA 81.2). Regarding non-metastatic PC (cStage I-III, n = 11), CTCs also had the highest diagnostic accuracy among the three markers tested (CTCs: 84.6%, CA19-9:80.7%, CEA 73.0%).

CONCLUSIONS

A newly developed microfluidic device could diagnose PB cancers by detecting CTCs. This trial was registered with the UMIN Clinical Trials Registry, no. UMIN000029808.

A Blood-based Gene-expression Scoring System for Cancer Screening in Patients With Branch-duct Intraductal Papillary Mucinous Neoplasms

BACKGROUND

In patients with branch-duct intraductal papillary mucinous neoplasms (BD-IPMN), we aimed to develop a novel blood-based biomarker utilizing a gene-expression profile for the detection of pancreatic malignancies, such as IPMN-derived carcinoma (IPMC) or pancreatic ductal adenocarcinoma (PDAC).

PATIENTS AND METHODS

We enrolled 40 patients with pancreatic tumors (24 BD-IPMNs, four IPMCs and 12 PDACs) and identified the characteristic gene-expression profiles in pancreatic malignancies. Subsequently, we constructed a gene-expression scoring system for the proper diagnosis of pancreatic malignancies. The result was validated in 14 patients (five IPMNs, three IPMCs and six PDACs).

RESULTS

The scoring system utilizing the expression levels of 13 genes showed high diagnostic yield (sensitivity=94.0%, specificity=92.0% and area under the curve=0.94), which was confirmed in the validation set. Furthermore, its diagnostic yield was not reduced even in early-stage pancreatic malignancies (sensitivity=85.0%, specificity=93.0% and area under the curve=0.88).

CONCLUSION

We developed a blood-based gene expression scoring system for cancer screening in patients with BD-IPMNs.

Esophagobronchial fistula complicated by esophageal achalasia treated by per-oral endoscopic myotomy

A 48-year-old man who underwent balloon dilation for esophageal achalasia more than 20 years prior developed severe dysphagia and cough during mealtimes. Endoscopic findings showed a markedly dilated esophagus with residue, narrowing of the esophagogastric junction (EGJ), and a fistula in the middle thoracic esophagus. Esophagography showed narrowing of the EGJ and outflow of contrast from the esophagus to the bronchus. In addition, computed tomography showed marked esophageal dilatation and diffuse granular shading in both lungs. Based on these imaging findings, the patient was diagnosed with deterioration of esophageal achalasia and an esophagobronchial fistula (EBF) secondary to achalasia. The increased intra-esophageal pressure caused by the achalasia was suspected to have inhibited the closure of the EBF. Therefore, we believed that per-oral endoscopic myotomy (POEM) would help treat the achalasia and simultaneously contribute to closing of the EBF. Immediately after POEM, the dysphagia and cough improved. Furthermore, the EBF was closed. 14 months after POEM, the patient did not exhibit deterioration of esophageal achalasia and EBF. To the best of our knowledge, there have been no reports of POEM implemented in cases of esophageal achalasia complicated by EBF. Therefore, this case is worth reporting.

Into which Region Should a Prophylactic Pancreatic Stent Be Inserted? A Propensity Score Matching Analysis

BACKGROUND AND AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is an important procedure for the diagnosis and treatment of pancreaticobiliary diseases. However, post-ERCP pancreatitis (PEP) is sometimes a mortal adverse event. Though pancreatic stent (PS) insertion has proven to be a useful prophylaxis for PEP in several past reports, the region of the pancreas into which the PS should be inserted is unknown. Therefore, this study investigated where a prophylactic PS for PEP should be inserted.

METHODS

In this retrospective study, we targeted 282 patients without past history of abdominal surgery and who underwent initial ERCP and insertion of prophylactic PS to prevent PEP between January 2007 and April 2019. Patients with PS insertion to the pancreatic head (head group) were compared with patients with PS insertion into the pancreatic body or tail (body/tail group) using propensity score matching for patient characteristics, ERCP procedures, and post-ERCP adverse events.

RESULTS

After propensity score matching and removing the cases with the PS passing spontaneously for ERCP procedures, 52 head group patients and 54 body/tail group patients were selected. The PEP rate was significantly higher in the head group than in the body/tail group (9.6% vs. 0%, p=0.026).

CONCLUSION

Pancreatic stent insertion in the pancreatic body/tail was more effective for preventing PEP than PS insertion in the pancreatic head.

Which scope is appropriate for endoscopic retrograde cholangiopancreatography after Billroth II reconstruction: An esophagogastroduodenoscope or a colonoscope?

BACKGROUND

Recently, with the advent of more advanced devices and endoscopic techniques, endoscopic retrograde cholangiopancreatography (ERCP) in Billroth II (B-II) patients has been increasingly performed. However, the procedures are difficult, and the techniques and strategies have not been defined.

AIM

To reveal the appropriate scope for ERCP in B-II patients.

METHODS

Sixty ERCP procedures were performed on B-II patients between June 2005 and May 2018 at Fukushima Medical University Hospital, and in 44 cases, this was the first ERCP procedure performed by esophagogastroduodenoscopy (EGDS) or colonoscopy (CS) after B-II gastrectomy. These cases were divided into two groups: 17 cases of ERCP performed by EGDS (EGDS group) and 27 cases of ERCP performed by CS (CS group). The patient characteristics and ERCP procedures were compared between the EGDS and CS groups.

RESULTS

The procedural time was significantly shorter in the EGDS group than in the CS group [median (range): 60 (20-100) vs 90 (40-128) min, P value < 0.01]. CS was an independent factor of a longer ERCP procedural time according to the univariate and multivariate analyses (odds ratio: 3.97, 95%CI: 1.05-15.0, P value = 0.04).

CONCLUSION

Compared to CS, EGDS shortened the procedural time of ERCP in B-II patients.

Pancreatic Neuroendocrine Neoplasm Invading the Entire Main Pancreatic Duct Diagnosed by a Preoperative Endoscopic Biopsy

A 78-year-old man was referred to our hospital for a detailed examination of a pancreatic tumor that filled the main pancreatic duct (MPD). The histological diagnosis of the endoscopic biopsy specimen was neuroendocrine tumor (NET) G3. The patient subsequently underwent total pancreatectomy. The histological diagnosis of the surgical specimen was also NET G3. This is the first report of a NET that occupied the MPD and was diagnosed by a preoperative endoscopic biopsy through the papilla of Vater. This case is a good example of a histopathological diagnostic method for pancreatic tumors invading the entire MPD.

Rare coincidence of intraductal papillary mucinous neoplasm and type 1 autoimmune pancreatitis

The present case involved a 60-year-old man with autoimmune pancreatitis (AIP). While his AIP was in remission for 6 years, a follow-up CE-CT revealed a dilated main pancreatic duct (MPD) and an enhanced mural nodule. Fluorodeoxyglucose uptake was positive on positron emission tomography. Endoscopic retrograde pancreatography showed a filling defect of the MPD, and pancreatoscopy revealed a nodule partially covered with papillary lesions. Although a repeat biopsy revealed no evidence of malignancy, we speculated that there was a high likelihood of main-duct-type intraductal papillary mucinous neoplasm (IPMN)-derived carcinoma concomitant with AIP. Subsequently, the patient underwent subtotal stomach-preserving pancreaticoduodenectomy. A surgical specimen showed a 35 mm protuberant papillary lesion with abundant stroma, located in the main duct of the pancreas. Further histological evaluation revealed that the nodule was predominantly composed of IPMN with low-grade dysplasia, which was accompanied by abundant IgG4-positive lymphoplasmacytic infiltration, and fibrosis existed predominantly around the IPMN. The epithelium of the cyst showed mucinous hyperplasia with focal papillary structures of gastric phenotype (MUC5A+, MUC6+, MUC1-, MUC2-, CDX-). After surgical resection, we did not find any imaging evidence suggesting a recurrent tumor and AIP relapse in the remnant pancreas. In conclusion, we report a case of IPMN coincidentally found in a patient with type 1 AIP. Active AIP may exaggerate the morphology of IPMN, and careful evaluation should be performed to select appropriate management.

Acquired resistance to trastuzumab/pertuzumab or to T-DM1 in vivo can be overcome by HER2 kinase inhibition with TAS0728

HER2‐targeting antibodies (trastuzumab, pertuzumab) and a HER2‐directed antibody‐drug conjugate (trastuzumab emtansine: T‐DM1) are used for the treatment of HER2‐overexpressing breast cancer. However, these treatments eventually become ineffective due to acquired resistance and there is an urgent need for alternative therapies. TAS0728 is a small‐molecule, irreversible selective HER2 kinase inhibitor. In the present study, we established new in vivo models of cancer resistance by continuous exposure to a combination of trastuzumab and pertuzumab or to T‐DM1 for evaluating the effect of TAS0728 on HER2 antibody‐resistant populations. Treatment with trastuzumab and pertuzumab or with T‐DM1 initially induced tumor regression in NCI‐N87 xenografts. However, tumor regrowth during treatment indicated loss of drug effectiveness. In tumors with acquired resistance to trastuzumab and pertuzumab or to T‐DM1, HER2‐HER3 phosphorylation was retained. Switching to TAS0728 resulted in a significant anti‐tumor effect associated with HER2‐HER3 signal inhibition. No alternative receptor tyrosine kinase activation was observed in these resistant tumors. Furthermore, in a patient‐derived xenograft model derived from breast cancer refractory to both trastuzumab/pertuzumab and T‐DM1, TAS0728 exerted a potent anti‐tumor effect. These results suggest that tumors with acquired resistance to trastuzumab and pertuzumab and to T‐DM1 are still dependent on oncogenic HER2‐HER3 signaling and are vulnerable to HER2 signal inhibition by TAS0728. These results provide a rationale for TAS0728 therapy for breast cancers that are refractory to established anti‐HER2 therapies.

Interstitial lung disease in advanced pancreatic ductal adenocarcinoma patients treated with gemcitabine and nab-paclitaxel combination therapy: a retrospective analysis

PURPOSE

Gemcitabine and nab-paclitaxel (GnP) combination therapy is a standard regimen for advanced pancreatic ductal adenocarcinoma (PDAC) worldwide; however, concerns regarding the unexpectedly high incidence of interstitial lung disease (ILD) have emerged. We investigated the incidence and predictive factors of ILD in PDAC patients who were treated with GnP combination therapy.

METHODS

Thirty-seven patients treated with GnP therapy as either 1st or 2nd line treatment were included, among whom seven developed ILD (18.9%). The clinical characteristics (age, etc.) were compared between patients with and without ILD. The diagnostic yield of the markers to predict the presence of ILD was calculated. The clinical course of the seven patients with ILD was summarized. Survival analysis was performed using the Kaplan-Meier method and log-rank test.

RESULTS

The median age was higher in patients with ILD (73.0 vs. 65.0 years old, p = 0.03), while no differences were observed in the other clinical characteristics. Among the three investigated markers, SP-D showed the best diagnostic yield (AUC = 0.94) for diagnosing ILD. Though one patient required steroid therapy and the discontinuation of GnP therapy, all patients could undergo subsequent treatment. In the survival analysis, the median survival time of PDAC patients with ILD was comparable to that of patients without ILD (25.1 vs. 24.5 months, p = 0.98).

CONCLUSION

ILD was observed in 18.9% of PDAC patients treated with GnP therapy. With appropriate management, no prognostic influence was observed.

Can the wet suction technique change the efficacy of endoscopic ultrasound-guided fine-needle aspiration for diagnosing autoimmune pancreatitis type 1? A prospective single-arm study

BACKGROUND

Other than surgery, endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) is the only procedure for histologically diagnosing autoimmune pancreatitis (AIP). However, adequate specimens are difficult to obtain. Recently, more adequate specimens were reported to be obtained with EUS-FNA with a wet suction technique (WEST) than with conventional EUS-FNA.

AIM

To histologically diagnose AIP by EUS-FNA with a WEST.

METHODS

Eleven patients with possible type 1 AIP between February 2016 and August 2018 underwent EUS-FNA with a WEST (WEST group), with four punctures by 19 or 22 G needles. As a historical control, 23 type 1 AIP patients who underwent no fewer than four punctures with 19 or 22 G needles were enrolled (DRY group). Patient characteristics and histological findings were compared between the two groups.

RESULTS

Three histopathological factors according to the International Consensus Diagnostic Criteria were significantly greater in the WEST group than the DRY group [lymphoplasmacytic infiltrate without granulocytic infiltration: 9 (81.8%) vs 6 (26.1%), P = 0.003, storiform fibrosis: 5 (45.5%) vs 1 (4.3%), P = 0.008, abundant (> 10 cells/HPF) IgG4-positive cells: 7 (63.6%) vs 5 (21.7%), P = 0.026]. Level 1 or level 2 histopathological findings were observed more often in the WEST group than in the DRY group [8 (72.7%) vs 3 (13.0%), P = 0.001].

CONCLUSION

EUS-FNA with a WEST was more successful than standard EUS-FNA in histologically diagnosing AIP.

Abstract A126: Acquired resistance to trastuzumab/pertuzumab, or to T-DM1 in vivo can be overcome by HER2 inhibition with TAS0728

Background: HER2-targeting antibodies (trastuzumab, pertuzumab) and an antibody-drug conjugate (trastuzumab emtansine: T-DM1) are available for the treatment of HER2 overexpressed breast cancer. TAS0728 is a small molecule, covalent-binding, selective inhibitor of HER2 kinase, and its assessment in humans is ongoing. Although HER2 targeting therapies with trastuzumab/pertuzumab, or T-DM1 initially show clinical activity, those treatments eventually become ineffective due to acquired resistance. Various resistant models to the therapies have been established in vitro to explore novel therapies for resistance. However, those models may not mimic patients’ tumors, because antibody dependent cellular cytotoxicity (ADCC) and/or pharmacokinetics of the drugs were not involved in the establishment of the models. In our previous report, we have established an acquired resistant model to T-DM1 in vivo. The model was sensitive to TAS0728. In the present study, we analyzed the molecular mechanism of T-DM1 resistance and mode of action of TAS0728 in the established model. Furthermore, we established another model with acquired resistance to trastuzumab and pertuzumab in mice, and investigated the sensitivity to TAS0728. Materials and Methods: To establish a resistant model to T-DM1, T-DM1 was administered at 10 mg/kg (q3w, i.v.) in NCI-N87 xenograft model until tumor regression and the subsequent re-growth of tumor were observed. Pharmacodynamics of T-DM1 at 10 mg/kg (q3w, i.v.) or TAS0728 at 60 mg/kg (q.d., p.o.) was evaluated in the tumors. To clarify the resistant mechanisms to T-DM1 and mode of action of TAS0728, molecular profiling of the resistant tumors was conducted by phospho-RTK array, RNA sequencing, and Western blotting. To establish a resistant model to trastuzumab/pertuzumab in vivo, the antibodies were administered concomitantly at 20 mg/kg each (q1w, i.p.) in the NCI-N87 xenograft model until tumor regression and the subsequent re-growth of tumor were observed. The mice were treated with the antibodies at 20 mg/kg each (q1w, i.p.) or TAS0728 at 60 mg/kg (q.d., p.o.) to compare antitumor effects. Results: In the T-DM1 resistant model, TAS0728 exerted antitumor effect associated with HER2 signal inhibition. RNA sequencing revealed that expression level of a candidate gene, which may be involved in the intracellular metabolism of T-DM1, was decreased in the T-DM1 resistant tumor. Alternative RTK activation was not observed. Next, we established a resistant model to trastuzumab/pertuzumab combination therapy in vivo. Although the antibodies initially induced tumor regression in the NCI-N87 xenograft model, ultimately, regrowth of tumors was observed. Once the tumors regrew during the treatment, the antibodies were no longer effective. On the other hand, switching to TAS0728 resulted in significant antitumor effect. Collectively, these results suggested that tumors with acquired resistance to trastuzumab/pertuzumab or T-DM1 are still addicted to the active HER2 signal, and were vulnerable to HER2 inhibition by TAS0728. Conclusion: The acquired resistance models to trastuzumab/pertuzumab or T-DM1 were established in vivo. Selective inhibition of HER2 kinase by TAS0728 is effective in the both resistant models. These results provide a rationale for therapy with TAS0728 in patients refractory to the established anti-HER2 therapy.

Citation Format: Hiroki Irie, Rumi Kawabata, Yayoi Fujioka, Fumio Nakagawa, Hideki Nagase, Hiraku Itadani, Kimihiro Ito, Junji Uchida, Shuichi Ohkubo, Kenichi Matsuo, Takeshi Sagara, Teruhiro Utsugi. Acquired resistance to trastuzumab/pertuzumab, or to T-DM1 in vivo can be overcome by HER2 inhibition with TAS0728 [abstract]. In: Proceedings of the AACR-NCI-EORTC International Conference on Molecular Targets and Cancer Therapeutics; 2019 Oct 26-30; Boston, MA. Philadelphia (PA): AACR; Mol Cancer Ther 2019;18(12 Suppl):Abstract nr A126. doi:10.1158/1535-7163.TARG-19-A126

Prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis using pancreatic stents: A review of efficacy, diameter and length

Although endoscopic retrograde cholangiopancreatography (ERCP) is an important procedure for the diagnosis and treatment of pancreaticobiliary diseases, post-ERCP pancreatitis (PEP) is the most frequent adverse event that can sometimes be fatal. However, prophylactic pancreatic stent (PS) insertion has been performed to prevent PEP in high-risk patients. In some randomized controlled trials (RCTs) and meta-analyses, the efficacy of prophylactic PS insertion has been shown to prevent PEP. In addition, several types of stents have been used to decrease PEP. In this review, we introduce the details of these RCTs and meta-analyses and reveal the specifications for stent placement, for example, the stent diameter and length and the pancreatic region into which the stent should be inserted.

Present state of endoscopic ultrasonography-guided fine needle aspiration for the diagnosis of autoimmune pancreatitis type 1

Autoimmune pancreatitis (AIP) is defined as pancreatitis caused by irregular narrowing of the pancreatic duct accompanied by pancreatic swelling, fibrosis and lymphocyte infiltration, events that are related to autoimmune mechanisms. The 2010 International Consensus Diagnostic Criteria for AIP defined pancreatitis as “type 1” when increased levels of serum IgG4 were present and other organs were involved; lymphoplasmacytic sclerosing pancreatitis was the main histological characteristic. Apart from surgery, endoscopic ultrasonography-guided fine needle aspiration (EUS-FNA) is the only method for the histological diagnosis of AIP; however, this method is difficult. The use of larger-diameter FNA needles and trucut biopsy did not improve the diagnostic performance of EUS-FNA, but it has improved gradually. In this review, we look back at past efforts to improve the diagnostic performance of EUS-FNA and reveal the present state of EUS-FNA for the histological diagnosis of AIP type 1.

Pancreatic stents to prevent post-endoscopic retrograde cholangiopancreatography pancreatitis: A meta-analysis

BACKGROUND

Endoscopic retrograde cholangiopancreatography (ERCP) plays a major role in the investigation and treatment of pancreaticobiliary diseases. However, post-ERCP pancreatitis (PEP) is a severe adverse effect. Prior meta-analyses have shown that prophylactic PS was useful for preventing PEP. However, abstract reports and patients who underwent endoscopic ampullectomy were included in the previous analyses. In addition, two meta-analyses involved non-randomized controlled trials (RCTs). The efficacy of PS for preventing severe PEP was different in each meta-analysis. Therefore, we performed the current meta-analysis, which included only full-text articles, and added new findings.

AIM

To reveal the efficacy of prophylactic pancreatic stent (PS) placement for preventing PEP.

METHODS

We searched the MEDLINE, Cochrane Library and PubMed databases for related RCTs. Among the reports retrieved, 11 studies were included in this meta-analysis. All full-text articles were published between 1993 and 2016. A total of 1475 patients were enrolled in the included studies; of these patients, 734 had a PS inserted, and 741 did not have a PS inserted. PEP and severe PEP occurrence were evaluated in this meta-analysis.

RESULTS

PEP was observed in all studies and occurred in 39 (5.3%) patients who received a PS. On the other hand, PEP occurred in 141 (19%) patients who did not receive a PS. The occurrence of PEP was significantly lower in the patients who underwent PS placement than in the patients who did not receive a PS (OR = 0.32; 95%CI: 0.23-0.45; P < 0.001). In addition, the occurrence of severe PEP was evaluated. Notably, the occurrence of severe PEP was not observed in the stent group; however, the occurrence of severe PEP was observed in 8 (1.3%) patients who did not have a PS inserted. Severe PEP occurred significantly less often in the stent group than in the no stent group (OR = 0.24; 95%CI: 0.06-0.94; P = 0.04).

CONCLUSION

In conclusion, prophylactic PS placement is useful for preventing PEP and severe PEP.

Appropriate number of biliary biopsies and endoscopic retrograde cholangiopancreatography sessions for diagnosing biliary tract cancer

BACKGROUND

Biliary ductal cancer (BDC) is a lethal disease; however, diagnosing BDC is challenging. Biliary biopsies are performed to pathologically diagnose BDC, but the appropriate parameters for biliary biopsy [number of biliary biopsies, number of endoscopic retrograde cholangiopancreatography (ERCP) sessions, etc.] are unknown.

AIM

To clarify what constitutes an adequate method for biliary biopsy.

METHODS

In total, 95 patients who underwent endoscopic biliary biopsy without choledochoscopy and who were pathologically diagnosed with BDC were enrolled in this study. The patients were divided into two groups. Seventy-six patients who were diagnosed by biliary biopsy were defined as the positive group (P group), and nineteen patients who were not diagnosed by biliary biopsy were defined as the negative group (N group). The patient characteristics and ERCP-related procedures were compared between the P and N groups.

RESULTS

The numbers of ERCP sessions and biliary biopsies were significantly different between the two groups [ERCP sessions (one/two), P group 72/4 vs N group 15/4, P value = 0.048; number of biliary biopsies, P group 2 (1-6) vs N group 2 (1-7), P value = 0.039]. In a multivariate analysis, fewer than 2 ERCP sessions was an independent factor influencing the positivity of the biliary biopsies.

CONCLUSION

This study clarified that ERCP and biliary ductal biopsy should only be performed once. If biliary cancer is not pathologically diagnosed after the first ERCP session, other methods (Endoscopic ultrasonography-guided fine needle aspiration or choledochoscopy-guided biliary ductal biopsy) should be employed.

TAS0728, A Covalent-binding, HER2-selective Kinase Inhibitor Shows Potent Antitumor Activity in Preclinical Models

Activated HER2 is a promising therapeutic target for various cancers. Although several reports have described HER2 inhibitors in development, no covalent-binding inhibitor selective for HER2 has been reported. Here, we report a novel compound TAS0728 that covalently binds to HER2 at C805 and selectively inhibits its kinase activity. Once TAS0728 bound to HER2 kinase, the inhibitory activity was not affected by a high ATP concentration. A kinome-wide biochemical panel and cellular assays established that TAS0728 possesses high specificity for HER2 over wild-type EGFR. Cellular pharmacodynamics assays using MCF10A cells engineered to express various mutated HER2 genes revealed that TAS0728 potently inhibited the phosphorylation of mutated HER2 and wild-type HER2. Furthermore, TAS0728 exhibited robust and sustained inhibition of the phosphorylation of HER2, HER3, and downstream effectors, thereby inducing apoptosis of HER2-amplified breast cancer cells and in tumor tissues of a xenograft model. TAS0728 induced tumor regression in mouse xenograft models bearing HER2 signal-dependent tumors and exhibited a survival benefit without any evident toxicity in a peritoneal dissemination mouse model bearing HER2-driven cancer cells. Taken together, our results demonstrated that TAS0728 may offer a promising therapeutic option with improved efficacy as compared with current HER2 inhibitors for HER2-activated cancers. Assessment of TAS0728 in ongoing clinical trials is awaited (NCT03410927).