A prospective cohort study of a new electrosurgical unit for preventing colorectal post-endoscopic submucosal dissection coagulation syndrome.

BACKGROUND AND AIM: Post-endoscopic submucosal dissection coagulation syndrome (PECS) is a recognized complication of colorectal endoscopic submucosal dissection (ESD); however, there is a lack of interventions for preventing PECS. We therefore conducted a prospective study to evaluate the utility of maXium, a novel electrosurgical unit, for preventing PECS. METHODS: This single-center, prospective cohort study prospectively enrolled patients undergoing colorectal ESD. The voltage and power of the electrosurgical units were measured. PECS was defined as a visual analog scale (VAS) ≥ 30 mm, an increase of VAS ≥ 20 mm from baseline, body temperature ≥ 37.5°C, or white blood cell count ≥ 10 000/µL after ESD. PECS was classified into type I (without extra-luminal air) and type II (with peri-luminal air). The primary endpoint was the incidence of PECS. A sample size of 92 patients was required to ensure the upper limit of the 90% CI for the incidence of PECS was less than 15%. RESULTS: At resistances greater than 400 Ω, the maXium unit allowed submucosal dissection with lower power than with the VIO300D unit. Ninety-one patients meeting the inclusion criteria were included in the final study analysis. The incidence of PECS was 16% (90% CI, 10-23%), comprising type I (11%) and type II (5%) PECS. Simple extra-luminal air without PECS was observed in 7% of patients. CONCLUSION: Use of the maXium electrosurgical unit did not reduce the incidence of PECS after colorectal ESD; however, the maXium unit had equivalent performance to a conventional electrosurgical unit used for colorectal ESD.

Background factors of idiopathic peptic ulcers and optimal treatment methods: a multicenter retrospective Japanese study.

This study investigated the trends in idiopathic peptic ulcers, examined the characteristics of refractory idiopathic peptic ulcer, and identified the optimal treatment. The characteristics of 309 patients with idiopathic peptic ulcer were examined. We allocated idiopathic peptic ulcers that did not heal after 8 weeks' treatment (6 weeks for duodenal ulcers) to the refractory group and those that healed within this period to the healed group. The typical risk factors for idiopathic peptic ulcer (atherosclerosis-related underlying disease or liver cirrhosis complications) were absent in 46.6% of patients. Absence of gastric mucosal atrophy (refractory group: 51.4%, healed group: 28.4%; p = 0.016), and gastric fundic gland polyps (refractory group: 17.6%, healed group: 5.9%; p = 0.045) were significantly more common in the refractory group compared to the healed group. A history of H. pylori eradication (refractory group: 85.3%, healed group: 66.0%; p = 0.016), previous H. pylori infection (i.e., gastric mucosal atrophy or history of H. pylori eradication) (refractory group: 48.5%, healed group: 80.0%; p = 0.001), and potassium-competitive acid blocker treatment (refractory group: 28.6%, healed group, 64.1%; p = 0.001) were significantly more frequent in the healed group compared to the refractory group. Thus, acid hypersecretion may be a major factor underlying the refractoriness of idiopathic peptic ulcer.

Krüppel-like Factor-4-Mediated Macrophage Polarization and Phenotypic Transitions Drive Intestinal Fibrosis in THP-1 Monocyte Models In Vitro.

Background and Objectives: Despite the fact that biologic drugs have transformed inflammatory bowel disease (IBD) treatment, addressing fibrosis-related strictures remains a research gap. This study explored the roles of cytokines, macrophages, and Krüppel-like factors (KLFs), specifically KLF4, in intestinal fibrosis, as well as the interplay of KLF4 with various gut components. Materials and Methods: This study examined macrophage subtypes, their KLF4 expression, and the effects of KLF4 knockdown on macrophage polarization and cytokine expression using THP-1 monocyte models. Co-culture experiments with stromal myofibroblasts and a conditioned medium from macrophage subtype cultures were conducted to study the role of these cells in intestinal fibrosis. Human-induced pluripotent stem cell-derived small intestinal organoids were used to confirm inflammatory and fibrotic responses in the human small intestinal epithelium. Results: Each macrophage subtype exhibited distinct phenotypes and KLF4 expression. Knockdown of KLF4 induced inflammatory cytokine expression in M0, M2a, and M2c cells. M2b exerted anti-fibrotic effects via interleukin (IL)-10. M0 and M2b cells showed a high migratory capacity toward activated stromal myofibroblasts. M0 cells interacting with activated stromal myofibroblasts transformed into inflammatory macrophages, thereby increasing pro-inflammatory cytokine expression. The expression of IL-36α, linked to fibrosis, was upregulated. Conclusions: This study elucidated the role of KLF4 in macrophage polarization and the intricate interactions between macrophages, stromal myofibroblasts, and cytokines in experimental in vitro models of intestinal fibrosis. The obtained results may suggest the mechanism of fibrosis formation in clinical IBD.

Long-term outcomes of nasogastric tube with Gastrografin for adhesive small bowel obstruction.

BACKGROUND: We had previously reported that the administration of Gastrografin through a nasogastric tube (NGT-G) followed by long tube (LT) strategy could be a novel standard treatment for adhesive small bowel obstruction (ASBO); however, the long-term outcomes after initial improvement remain unknown. This study aimed to analyze the long-term outcomes of first-line NGT-G. METHODS: Enrolled patients with ASBO were randomly assigned to receive LT or NGT-G between July 2016 and November 2018. Thereafter, the cumulative surgery rate, cumulative recurrence rate, and overall survival (OS) rate were analyzed. In addition, subset analysis was conducted to determine the cumulative recurrence rate according to colonic contrast with Gastrografin at 24 h. RESULTS: A total of 223 patients (LT group, n = 111; NGT-G group, n = 112) were analyzed over a median follow-up duration of 550 days. The cumulative 1-year surgery rates, cumulative 1-year recurrence rates, and 1-year OS rates in the LT and NGT-G groups were 18.8% and 18.1%, 30.0% and 31.7%, and 99.1% and 96.6%, respectively; no significant differences were observed between both groups. In the NGT-G group, a negative colonic contrast at 24 h demonstrated a higher tendency for future recurrence compared with a positive colonic contrast at 24 h (1-year recurrence rate: negative contrast, 46.9% vs positive contrast, 27.6%). CONCLUSIONS: Gastrografin through a nasogastric tube followed by LT can be a promising treatment strategy for ASBO, with long-term efficacies equivalent to initial LT placement.

Combination of talaporfin photodynamic therapy and Poly (ADP-Ribose) polymerase (PARP) inhibitor in gastric cancer.

Photodynamic therapy (PDT) utilizes photochemical reactions induced by a photosensitizer and light in the target tissue and is used to treat various cancers. There is a high degree of anticipation of success regarding the application of PDT with talaporfin (photosensitizer) for gastric cancer. Olaparib is an oral inhibitor of Poly (ADP-Ribose) polymerase (PARP) and has demonstrated optimal efficacy and clinical activity in trials. Therefore, the aim of the present study was to investigate the efficacy of talaporfin PDT combined with olaparib for gastric cancer. MKN45, a gastric cancer cell line, was incubated with talaporfin, followed by irradiation, in the presence/absence of olaparib. Talaporfin PDT and olaparib exhibited excellent synergistic action in a concentration-dependent manner. PARP-DNA complexes were characterized based on bound chromatin using Western blot analyses. The combination of talaporfin PDT and olaparib enhanced PARP1 accumulation (the entrapment of PARP1-DNA complexes) in bound chromatin. The combination of talaporfin PDT and olaparib induced DNA double-strand breaks, which was confirmed by evaluating phosphorylated histone H2AX. Xenograft tumor mouse models were established, and antitumor effects were analyzed. In vivo, tumor growth was significantly suppressed following PDT with talaporfin and olaparib. Our results demonstrated that olaparib enhances the efficacy of talaporfin PDT by inducing the formation of PARP-DNA complexes. Therefore, our results suggest that the combination of talaporfin PDT and olaparib is a potential antitumor therapy for gastric cancer.

Optimal definition of coagulation syndrome after colorectal endoscopic submucosal dissection: a post hoc analysis of randomized controlled trial.

PURPOSE: Endoscopic clipping closure after colorectal endoscopic submucosal dissection (ESD) did not reduce the incidence of post-ESD coagulation syndrome (PECS) in our recent randomized controlled trial (RCT); however, the definition of PECS is still controversial. The aim of this study is to establish optimal definition of PECS with additional analysis of RCT based on another definition. METHODS: In this multicenter, single-blind RCT, individuals were randomly assigned to colorectal ESD followed by endoscopic clipping closure or non-closure. In this post hoc analysis, the definition of PECS was modified as both localized abdominal pain on visual analogue scale and inflammatory response (fever or leukocytosis), from either localized abdominal pain or inflammatory response in the original study. All participants underwent a computed tomography after ESD, and PECS was classified into type I, conventional PECS without extra-luminal air, and type II, PECS with peri-luminal air. RESULTS: A total of 155 patients (84 in the non-closure group and 71 in the closure group) were analyzed. As a result of criteria modification, 21 type I PECS and four type II PECS cases in the original study, which included patients with clear pain and inflammatory response, were downgraded to no adverse event and simple peri-luminal air, respectively. The frequency of PECS showed no significant difference between non-closure and closure groups. CONCLUSION: Clipping closure after colorectal ESD does not reduce the incidence of PECS regardless of the diagnostic criteria. Either localized abdominal pain or inflammatory response might be optimal criteria of PECS (UMIN000027031). TRIAL REGISTRATION NUMBER: UMIN000027031 DATE OF REGISTRATION: April 18, 2017.

Relationship between Immunophenotype and Clinicopathological Findings for Superficial Nonampullary Duodenal Epithelial Tumor.

INTRODUCTION: The natural history and prognosis of superficial nonampullary duodenal epithelial tumors (SNADETs) remain uncertain. We elucidated the relationship between immunophenotype and clinicopathological features. MATERIALS AND METHODS: A total of 98 SNADETs were divided into 3 groups according to immunohistochemical findings: gastric phenotype (G type), gastrointestinal phenotype (GI type), and intestinal phenotype (I type). Cellular dysplasia was divided into low-grade dysplasia and high-grade dysplasia/adenocarcinoma (≥HGD). White opaque substance (WOS) deposition was categorized into diffuse WOS, partial WOS, and no WOS, based on endoscopic findings. RESULTS: Of the 98 SNADETs, 4 lesions (4.1%) were G type, 32 lesions (32.7%) were GI type, and 62 lesions (63.2%) were I type. All G-type SNADETs were located in the oral side of the papilla including the bulb, and the rate of bulbar lesions was significantly higher in the G type than in the GI and I types (p = 0.004). The most frequent type of WOS was no WOS (4/4, 100%) for G type, partial WOS (19/32, 59.4%) for GI type, and diffuse WOS (34/62, 54.8%) for I type (p < 0.001), and loss of intestinal character was significantly correlated with WOS deficiency. GI/I-type SNADETs with partial or no WOS and G-type SNADETs were associated with ≥HGD. Additionally, the frequency of ≥HGD lesion was significantly higher in the CD10-negative group than in the CD10-positive group (57.1 vs. 19.8%, p = 0.043). CONCLUSION: Pathological intestinal character was correlated with the presence of WOS, and CD10 loss was associated with malignant potential of SNADETs.

Serum Exosomal Dicer Is a Useful Biomarker for Early Detection of Differentiated Gastric Adenocarcinoma.

BACKGROUND AND AIM: A recent basic study identified that Dicer is contained in exosomes derived from cancer cells and plays crucial roles in microRNA maturation and cancer development. Based on this novel basic concept, we analyzed the usefulness of serum exosomal Dicer as a diagnostic biomarker for gastrointestinal cancers. METHODS: Enrolled participants (691) were categorized into 3 groups: gastric cancer (GC) cohort, 183 patients (90 healthy controls (HCs) and 93 GC patients); esophageal cancer (EC) cohort, 115 patients (90 HCs and 25 EC patients); and colorectal cancer (CRC) cohort, 188 patients (92 HCs and 96 CRC patients) after age- and sex matching using the propensity score. The quality of isolated serum exosomes was validated with an electron microscope, particle size analyzer, and exosome marker, CD63. RESULTS: Serum exosomal Dicer was significantly higher in the GC group than in the HC group (p = 0.004), whereas no significant differences were found in both EC and CRC cohorts. Serum exosomal Dicer was significantly higher in only differentiated gastric adenocarcinoma and not in the undifferentiated type. Moreover, serum exosomal Dicer showed no significant differences regardless of Helicobacter pylori (H. pylori) status. The biomarker panel combining serum exosomal Dicer with H. pylori status distinguished between HC and differentiated GC patients with an area under the curve (AUC) of 0.762. As for early-stage diagnosis, this combination distinguished between HC and stage I differentiated GC with an AUC = 0.758. CONCLUSIONS: Serum exosomal Dicer is a potential noninvasive diagnostic biomarker for early detection of differentiated gastric adenocarcinoma.

A multicenter, single-blind randomized controlled trial of endoscopic clipping closure for preventing coagulation syndrome after colorectal endoscopic submucosal dissection.

BACKGROUND AND AIMS: Post endoscopic submucosal dissection coagulation syndrome (PECS) occasionally occurs after colorectal endoscopic submucosal dissection (ESD), presenting with localized abdominal pain and inflammation. We conducted a randomized controlled trial (RCT) to assess the usefulness of endoscopic clipping closure to prevent PECS and delayed perforation (DP). METHODS: This is a multicenter, single-blind RCT. Prospectively enrolled patients undergoing colorectal ESD were randomly allocated to endoscopic clipping closure and nonclosure after ESD, stratifying by institution and tumor size. All participants underwent a computed tomography scan after ESD. PECS was defined as visual analog scale (VAS) ≥30 mm, an increase in VAS ≥20 mm from baseline, body temperature ≥37.5°C or white blood cells ≥10,000/µL after colorectal ESD. DP was defined as PECS accompanied by extraluminal air. The preplanned sample size was 320 patients, and the primary endpoint was the rate of PECS/DP. RESULTS: At the planned interim analysis, this trial was terminated by recommendation of the independent data and safety monitoring committee because conditional power with superiority was lower than the preplanned futility limit. Finally, 155 patients were analyzed. The rate of PECS/DP was 16% (95% confidence interval [CI], 8%-23%) in the nonclosure group and 24% (95% CI, 14%-34%) in the closure group (P = .184). All cases of DP were within minor criteria, and all PECS/DP patients were managed conservatively without surgical treatment. Simple periluminal air without PECS was observed in 16% (95% CI, 8%-23%) in the nonclosure group and 10% (95% CI, 3%-17%) in the closure group. CONCLUSION: Endoscopic clipping closure could not reduce the high incidence of PECS/DP after colorectal ESD. (University Hospital Medical Network Clinical Trials Registry number: UMIN000027031.).

Excellent antitumor effects for gastrointestinal cancers using photodynamic therapy with a novel glucose conjugated chlorin e6.

BACKGROUND: Photodynamic therapy (PDT) exploits the reaction between photosensitizer and irradiated light to generate potentially therapeutic reactive oxygen species such as singlet oxygen in cancer cells. We have reported several sugar-conjugated chlorins that express stronger antitumor effects in PDT than talaporfin sodium (TS), a second-generation photosensitizer clinically used in Japan. In this study, we developed a novel glucose-conjugated chlorin e6 (G-chlorin e6) and evaluated its antitumor effects. METHODS: G-chlorin e6 was synthesized with a core photosensitizer chlorin e6 conjugated to glucose. We measured the half maximal inhibitory concentration (IC50) to compare the PDT effects of G-chlorin e6 and TS, and flow cytometry was performed to examine the accumulation of G-chlorin e6 in cancer cells. We also compared the accumulation of G-chlorin e6 between normal immortalized esophageal epithelial cells and esophageal cancer cells. Antitumor effects of G-chlorin e6 PDT were finally analyzed in allograft tumor mouse models. RESULTS: PDT in vitro using G-chlorin e6 elicited 9, 000-34,000 times stronger antitumor effects than TS, and there was 70-190 times more G-chlorin e6 accumulated than TS by flow cytometry. G-chlorin e6 accumulated more selectively in esophageal cancer cells than in esophageal immortalized epithelial cells, and in an allograft model, PDT with G-chlorin e6 showed very strong antitumor effects and a 40% complete response (CR) rate. CONCLUSIONS: G-chlorin e6 showed excellent tumor selectivity, and PDT using G-chlorin e6 revealed the strongest anti-tumor effects among all sugar-conjugated chlorins that we have studied. G-chlorin e6 is considered to be the best photosensitizer for next-generation PDT.

Long-term outcomes of endoscopic gallbladder stenting in high-risk surgical patients with calculous cholecystitis (with videos).

BACKGROUND AND AIMS: Recently, endoscopic gallbladder stenting (EGBS) has been performed to prevent recurrences in high-risk surgical patients with cholecystitis. However, evidence regarding the long-term outcomes of EGBS is sparse. We investigated the cholecystitis recurrence rate in high-risk surgical patients with acute calculous cholecystitis and compared the cholecystitis recurrence rates in patients in whom EGBS was performed with those in patients who were observed after percutaneous drainage. METHODS: We studied 64 consecutive high-risk surgical patients with acute calculous cholecystitis who required gallbladder decompression between 2007 and 2014. We divided the patient cohort into patients who underwent observation after percutaneous drainage between 2007 and 2011 (OAPD group) and those who underwent EGBS between 2012 and 2014 (EGBS group), and we compared the groups. RESULTS: The technical success rate of EGBS was 82.9% based on the intention-to-treat analysis. The cholecystitis recurrence rates were 17.2% in the OAPD group and 0% in the EGBS group, a difference that was significant (P = .043). There was also a significant difference between the groups with respect to the time to recurrent cholecystitis, which was determined by using Kaplan-Meier analysis (P = .015). The overall biliary event rates were 24.1% in the OAPD group and 9.1% in the EGBS group, and no significant difference was noted (P = .207). CONCLUSION: EGBS reduced the recurrence of cholecystitis in high-risk surgical patients with calculous cholecystitis. However, stent-related adverse events may occur, and modifications are necessary to reduce these.

Reintervention for stent occlusion after bilateral self-expandable metallic stent placement for malignant hilar biliary obstruction.

BACKGROUND AND AIM: Endoscopic reintervention for stent occlusions following bilateral self-expandable metallic stent (SEMS) placement for malignant hilar biliary obstruction (MHBO) is challenging, and time to recurrent biliary obstruction (RBO) of the revisionary stent remains unclear. We aimed to clarify a suitable reintervention method for stent occlusions following bilateral SEMS placement for MHBO. METHODS: Between 2002 and 2014, 52 consecutive patients with MHBO who underwent endoscopic reintervention for stent occlusion after bilateral SEMS placement were enrolled at two university hospitals and one tertiary care referral center. We retrospectively evaluated the technical and functional success rates of the reinterventions, and the time to RBO of the revisionary stents. RESULTS: Technical and functional success rates of the reinterventions were 92% (48/52) and 90% (43/48), respectively. Univariate analysis did not determine any significant predictive factors for technical and functional failures. Median time to RBO of the revisionary stents was 68 days. Median time to RBO was significantly longer for revisionary SEMS placement than for plastic stent placement (131 days vs 47 days, respectively; log-rank test, P = 0.005). Revisionary SEMS placement was the only independent factor that was significantly associated with a longer time to RBO of the revisionary stent in the multivariate Cox proportional hazards analysis (hazard ratio 0.37; 95% confidence interval 0.14-0.95; P = 0.039). CONCLUSION: Revisionary SEMS placement is a suitable endoscopic reintervention method for stent occlusion following bilateral SEMS placement from the perspective of time to RBO of the revisionary stent.

Difficult diagnoses of two cases of double cancer involving malignant lymphoma with peritoneal localization and malignant abdominal tumor.

We encountered two cases of malignant lymphoma with peritoneal localization complicated by sigmoid colon cancer and hepatocellular carcinoma. Multiple primary cancers were suspected on the basis of differences in absorption values on computed tomography (CT) and differences in the degree of accumulation on positron emission tomography CT; however, a definitive diagnosis based on these findings alone was difficult. Endoscopic ultrasound-guided fine-needle aspiration was useful for determining the diagnosis and treatment strategy. In cases of double cancers involving malignant lymphoma with peritoneal localization and malignant abdominal tumor, differentiation and staging are often difficult, which increases the risk of selecting the wrong treatment strategy. Therefore, care must be taken when diagnosing these diseases.

[Two cases of distal duodenal gastrointestinal stromal tumor diagnosed by endoscopic ultrasound-guided fine-needle aspiration biopsy].

Gastrointestinal stromal tumor (GIST) of the duodenum is rare. Obtaining tissue samples of GIST in the duodenum is difficult, especially when the tumor is located in the distal duodenum. Thus, preoperative pathological diagnosis often becomes difficult. We performed endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) biopsy for two cases with submucosal tumors in the third portion of the duodenum. Tissue samples were successfully obtained and diagnosed as GIST. Partial duodenectomy was performed in the two patients. Thus, we believe that EUS-FNA is a potentially useful diagnostic aid for submucosal tumors in the third portion of the duodenum, and it should be attempted before more invasive approaches.

[Gadolinium as an alternative radiocontrast agent in patients with allergy to iodine-based contrast provide for useful diagnostic imagings and safely treatment of biliary tract diseases].

Diagnosis and treatment of biliary tract disease requires an intraductal radiocontrast agent. Although iodine-based contrast medium is commonly used, some patients show severe allergy to iodinated contrast agent. We have retrospectively reviewed the usefulness and safety of gadolinium as an alternative radiocontrast agent in 3 patients with allergy to iodine-based contrast medium in the diagnosis and treatment of biliary tract diseases. In case 1, percutaneous transhepatic biliary drainage and cholangiography were performed successfully and it was possible to visualize an intrahepatic bile duct stone. Percutaneous transhepatic cholangioscopic lithotomy was performed and the intrahepatic bile duct stone was removed. In case 2, endoscopic biliary lithotripsy was performed. In case 3, percutaneous transhepatic cholangiography and cholangioscopy provided a diagnosis of moderately differentiated carcinoma. He underwent pancreatoduodenectomy. Postoperative cholangiograms were also obtained successfully. Gadolinium contrast agent is an alternative to iodine-based cholangiography for the patients with allergy to iodine.

[A case of intraductal papillary mucinous carcinoma found with acute obstructive suppurative pancreatic ductitis and liver abscess, and associated with a pancreatobiliary fistula].

We report a rare case of intraductal papillary mucinous carcinoma (IPMC) with acute obstructive suppurative pancreatic ductitis (AOSPD), liver abscess, and pancreatobiliary fistula formation. A man in his sixties was admitted to our hospital with a chief complain of high grade fever and anorexia. CT and MRI revealed a multilocular cystic lesion in the pancreatic head, fistula formation between the common bile duct and this cystic lesion, and multiple liver abscess. We performed endoscopic nasopancreatic drainage for the AOSPD, endoscopic biliary drainage for the biliary flow obstruction, and percutaneous transhepatic drainage for the liver abscess. Klebsiella pneumoniae was detected in the culture of pancreatic juice and liver abscess, but not in the bile and blood culture. These culture studies revealed that the liver abscess was caused by AOSPD. The patient underwent pancreaticoduodenectomy for the IPMC. The pathological diagnosis was IPMC.

Anti-tumor immunity enhancement by photodynamic therapy with talaporfin sodium and anti-programmed death 1 antibody.

Photodynamic therapy (PDT) is a relatively non-invasive anti-cancer therapy that employs a photosensitizer with a specific wavelength of light irradiation. PDT induces direct cell killing and enhancement effects on tumor immunity, but its underlying mechanism remains unknown. Here, we perform a basic analysis of the anti-tumor effect of talaporfin sodium (TS)-PDT as well as its synergism with the immune checkpoint inhibitor anti-programmed death 1 (anti-PD-1) antibody. We estimate the cell death mechanism induced by TS-PDT and the induction of damage-associated molecular patterns (DAMPs) by TS-PDT in vitro. We establish a syngeneic mouse model of bilateral flank tumors and verify the enhancement of the abscopal effect on the non-irradiated side. TS-PDT induced apoptosis, necrosis, and autophagy-associated cell death in vitro. TS-PDT induced the release and/or expression of DAMPs in vitro. Tumor growth was inhibited in the TS-PDT and anti-PD-1 antibody combination group compared with other single-treatment or non-treatment groups in vivo. In summary, TS-PDT induces the release and/or expression of DAMPs, indicating that it activates innate immunity. PD-1 blockage enhances the anti-tumor immunity induced by TS-PDT. Thus, our results demonstrate that the combination of TS-PDT and anti-PD-1 antibody can potentially be used for anti-tumor therapy.

Photodynamic therapy using mannose-conjugated chlorin e6 increases cell surface calreticulin in cancer cells and promotes macrophage phagocytosis.

Photodynamic therapy (PDT) damages cancer cells via photosensitization using harmless laser irradiation. We synthesized a new photosensitizer, mannose-conjugated-chlorin e6 (M-chlorin e6), which targets mannose receptors that are highly expressed on M2-like tumor-associated macrophages (M2-TAMs) and cancer cells. In our previous study, we demonstrated that M-chlorin e6 PDT reduces tumor volume and decreases the proportion of M2-TAMs. Whether M-chlorin e6 PDT-treated cancer cells activate tumor immunity remains unclear, although the decrease in M2-TAMs is thought to be a direct injurious effect of M-chlorin e6 PDT. Calreticulin (CRT) is exposed at the surface of the membrane of cancer cells in response to treatment with chemotherapeutic agents such as anthracycline and oxaliplatin. Surface-exposed CRT induces phagocytosis of CRT receptor-positive cells, including macrophages, inducing anticancer immune responses. In the present study, we found that M-chlorin e6 PDT increases CRT on the surface of cancer cells, leading to macrophage phagocytosis of cancer cells. Furthermore, M-chlorin e6 PDT increases CD80+CD86+ macrophages. These results suggest that M-chlorin e6 PDT exerts anti-tumor effects by both enhancing the phagocytosis of cancer cells and strengthening the anti-tumor phenotype of macrophages.

Relationship between gene mutations and clinicopathological features in nonampullary duodenal epithelial tumors.

BACKGROUND: Molecular features of nonampullary duodenal epithelial tumors (NADETs) remain unclear. AIM: The aim of this study is to determine the association between the genetic features and clinicopathological findings of NADETs. METHODS: In total, 75 NADETs were enrolled in this study, and was performed targeted DNA sequencing of the GNAS, KRAS, TP53, and APC genes. Histological grade was classified as category 3 or category 4/5 according to the Vienna classification, and the immunophenotype was categorized as the gastric phenotype (G type), gastrointestinal phenotype (GI type), or the intestinal phenotype (I type). RESULTS: The prevalence of GNAS and KRAS mutations was significantly higher in the G type than in the GI/I type (GNAS, P = 0.027; KRAS, P = 0.005). In contrast, the frequency of TP53 mutations was significantly higher in the GI/I type than in the G type (P = 0.049). Notably, APC mutations, excluding c.4479 G>A which was synonymous mutation, were more frequently identified in category 4/5 tumors than in category 3 tumors (50% vs. 24.5%; P = 0.039). CONCLUSION: G-type NADETs harbored frequent GNAS and KRAS mutations, whereas TP53 mutations are common in NADETs with intestinal features. APC mutations were significantly associated with high-grade neoplasia and invasive carcinoma.

The Risk Analyses of Lymph Node Metastasis and Recurrence for Submucosal Invasive Colorectal Cancer: Novel Criteria to Skip Completion Surgery.

(1) Background: Additional surgical resection after endoscopic resection (ER) is recommended for patients with submucosal invasive colorectal cancer (pT1 CRC) who have risk factors for lymph node metastasis (LNM) (high-risk pT1 CRC). This study aimed to identify risk factors for LNM and metastatic recurrence and to determine the low-risk population for whom additional surgery can be omitted among high-risk pT1 CRCs. (2) Methods: We retrospectively identified 404 patients with pT1 CRC who underwent ER or surgery, and patients were divided into three groups: low-risk (n = 79); high-risk pT1 with ER (n = 40); and high-risk with surgery (n = 285). We also enrolled another 64 patients with high-risk pT1 CRC in an independent validation cohort. (3) Results: In the high-risk with surgery group, LNM was seen in 11.2%, and vascular and lymphatic invasions were significantly independent risk factors for LNM on multivariate analysis. No LNMs were observed in pT1 CRCs with a negative vertical margin and SM invasion depth ≤2000 µm that had no other risk factors except for budding. Five patients developed metastatic recurrence in the high-risk with surgery group, and rectal cancer and undifferentiated histology were significantly independent risk factors for poor relapse-free survival. No LNM or recurrent cases were seen in high-risk pT1 CRCs that met these criteria: differentiated adenocarcinoma, no lymphovascular invasion, colon cancer, SM invasion depth ≤2000 µm, and a negative vertical margin, which were validated in an independent validation cohort. (4) Conclusions: Completion surgery may be skipped for high-risk pT1 CRCs that meet our proposed criteria.