Preclinical toxicological assessment of amido-bridged nucleic acid-modified antisense oligonucleotides targeting synaptotagmin XIII for intra-abdominal treatment of peritoneal metastasis of gastric cancer.

BACKGROUND: Peritoneal metastasis of gastric cancer is closely associated with dismal prognosis. In previous preclinical proof-of-concept studies, an amido-bridged nucleic acid (AmNA)-modified antisense oligonucleotide (ASO), designated ASO-4733 that targets the gene encoding synaptotagmin XIII (SYT13), inhibited cellular functions required for the formation of peritoneal metastasis of gastric cancer cells. ASO-4733 achieved therapeutic effects when intra-abdominally administered to mouse xenograft models. Here, we conducted an analysis of Syt13-deficient mice to determine the pharmacokinetics and toxicity of intra-abdominal administration of ASO-4733. METHODS: The effects of Syt13-deficiency in mice were determined. Good Laboratory Practice toxicity tests and the toxicokinetics of intra-abdominal administration of ASO-4733 were conducted in cynomolgus monkeys and rats. The pharmacokinetics of ASO-4733 administered intravenously or intra-abdominally to rats were investigated. RESULTS: Syt13-deficient mice exhibited normal reproduction, organ functions, and motor functions. Weekly intra-abdominal administration of ASO-4733 (125 mg/kg), corresponding to a 50-fold increase of the estimated clinical dose for 4 weeks, was well tolerated by cynomolgus monkeys. In rats, off-target toxicity (not attributable to hybridization) was observed after weekly intra-abdominal administration of ASO-4733. Blood concentrations of ASO-4733 were lower and rose more slowly after intra-abdominal administration compared with intravenous administration. CONCLUSIONS: The preclinical profile of intra-abdominal administration of ASO-4733 demonstrated its suitability for entry into clinical trials of patients with peritoneal metastasis of gastric cancer.

Oncological similarities between large type 3 and type 4 tumors in patients with resectable gastric cancer: a propensity score-matched analysis of a multi-institutional dataset.

BACKGROUND: Large type 3 (diameter ≥ 8 cm) and type 4 gastric cancers have been arbitrarily combined in Japan as a single entity. However, whether these two types are oncologically similar remain unclear. This study aimed to clarify this issue. METHODS: In this retrospective study, we analyzed a database of 3,575 patients from nine institutions who underwent gastrectomy between 2010 and 2014. Using propensity scores to balance significant variables, we compared prognoses and tumor recurrences. RESULTS: Of patients with clinical T3/T4 who underwent R0 resection, 75 and 73 had large type 3 and 4 tumors, respectively. Patients with type 4 tumors had significantly lower overall survival rates than those of patients with large type 3 tumors (hazard ratio [HR] 1.77; 95% confidence interval [CI] 1.14-2.74). However, among the large type 3 tumors, a remarkable difference in prognosis was observed between the differentiated and undifferentiated histological types. A comparison was made between large type 3 with undifferentiated phenotype and type 4, each with 39 patients after propensity score matching. Outcomes in both groups were similar in terms of overall survival (HR 1.28; 95% CI 0.73-2.25) and relapse-free survival (HR 1.34; 95% CI 0.80-2.27). No statistically significant differences were observed in the incidence of peritoneal recurrence (35.9% vs. 46.1%, P = 0.36) and lymph node recurrence (25.6% vs. 12.8%, P = 0.15). CONCLUSIONS: Large type 3 tumors with undifferentiated phenotype and type 4 tumors were oncologically similar. This subgroup could be considered as a new entity for future clinical trials.

Outcomes of surgical treatment for enterovesical fistula in Crohn's disease.

Enterovesical fistula (EVF) in Crohn's disease (CD) often does not improve with medical treatment and requires surgical treatment. The surgical treatment strategy for EVF in CD is definitive resection of the intestinal tract side, and performing a leak test using dye injection into the bladder after EVF dissection to determine the appropriate surgical procedure for the bladder side. This study aimed to evaluate the outcomes of surgical treatment for EVF in CD. Twenty-one patients who underwent surgery for EVF between 2006 and 2021 were included and retrospectively evaluated for clinical background, surgical procedures, and postoperative complications. The most common origin of EVF was the ileum (17 cases; 81%), and the most common site of EVF formation was the apex (12; 57%). Surgical approaches were laparotomy in 11 (52%) cases and laparoscopy in 10 (48%). Surgical procedures on the bladder side were fistula dissection in 13 (62%) cases and sutured closure of fistula in 8 (38%). A comparison of approaches revealed no significant difference in operative time, but the amount of blood loss was significantly less in the laparoscopy (p < 0.01). There was no significant difference in the occurrence of postoperative complications between approaches. Postoperative anti-TNF-α antibody agents were used in 17 (81%) cases, and there were no cases of recurrent EVF. In conclusion, definitive resection of the intestinal tract and minimal treatment on the bladder side were sufficient to achieve satisfactory outcomes for EVF in CD.

The long-term quality of life after distal and pylorus-preserving gastrectomy for stage I gastric cancer: A prospective multi-institutional study (CCOG1601).

PURPOSE: While regarded as function-preserving gastrectomy, few prospective longitudinal clinical trials have addressed the postoperative quality of life (QOL) after pylorus-preserving gastrectomy (PPG). We prospectively compared chronological changes in postoperative body weight and the QOL between PPG and distal gastrectomy (DG) for pathological Stage I gastric cancer (GC). METHODS: We conducted a multi-institutional prospective study (CCOG1601) to evaluate patients who underwent DG and PPG. The QOL was examined using the European Organization for Research and Treatment of Cancer Quality of life questionnaire-C30 (EORTC QLQ-C30) and the Post-Gastrectomy Syndrome Assessment Scale-37 (PGSAS-37). A total of 295 patients were enrolled from 15 institutions, and propensity score matching was performed to adjust for the essential variables for comparison analyses. RESULTS: After propensity score matching, 25 pairs of patients were identified. In the first postoperative month, DG achieved a superior nausea and vomiting score (EORTC QLQ-C30) and meal-related distress, indigestion, and dumping scores (PGSAS-37). No significant differences were noted between DG and PPG in the long-term QOL. Postoperative body weight loss was similar in both groups. CONCLUSIONS: This prospective observational study failed to demonstrate the superiority of PPG over DG in terms of postoperative body weight changes and the QOL.

Prognostic Impact of CDKN2A Mutations Associated With Smoking and Drinking History in Japanese Digestive Cancers.

BACKGROUND/AIM: Organs of the digestive system are frequent sites of cancer development, and digestive tract cancers are the leading causes of death worldwide, including in Japan. Most of these cancers are associated with smoking or drinking habits. This study focused on the clinical and genomic characteristics of patients with these cancers using the Center for Cancer Genomics and Advanced Therapeutics (C-CAT) database, which comprises a large volume of data on Japanese patients who have undergone tumor profiling gene panel tests. PATIENTS AND METHODS: The genomic and clinical data from patients with digestive tract cancers registered in C-CAT between 2019 and 2023 were retrospectively reviewed. The data were derived from 412 patients with esophageal squamous cell carcinoma, 558 with gastric adenocarcinoma, 3,368 with colorectal adenocarcinoma, 139 with hepatocellular carcinoma, 2,050 with cholangiocarcinoma, and 2,552 with pancreatic ductal adenocarcinoma. RESULTS: CDKN2A, CDKN2B, and MTAP mutations were associated with both smoking and drinking history, and patients with these mutations had a worse prognosis. Almost all gene alterations in CDKN2B and MTAP were deletions, often accompanied by CDKN2A deletion. CDKN2A mutation emerged as the most decisive prognostic factor among these mutations. Although CDKN2A mutations were frequently seen in esophageal squamous cell carcinoma, cholangiocarcinoma, and pancreatic ductal adenocarcinoma, statistically significant differences in survival outcomes were only identified in the latter two. CONCLUSION: CDKN2A mutations were associated with smoking and drinking in digestive cancers. This mutation was prevalent among patients with cholangiocarcinoma and pancreatic ductal adenocarcinoma, for whom they could serve as prognostic factors.

Therapeutic Potential of Antibody Targeting Neuronal Pentraxin Receptor in Esophageal Squamous Cell Carcinoma.

BACKGROUND: Esophageal squamous cell carcinoma (ESCC) has a poor prognosis despite advances in multidisciplinary treatments and immune checkpoint inhibitors. We previously reported that neural pentraxin receptor (NPTXR), a transmembrane protein mainly expressed in the brain and involved in synaptic transmission, is implicated in gastric cancer malignancy. This study evaluated the expression and function of NPTXR in ESCC, the therapeutic potential of monoclonal antibody (mAb) against NPTXR, and its prognostic value in ESCC patients. METHODS: The study involved analyzing the NPTXR expression in 21 ESCC cell lines and total 371 primary ESCC tissue samples using quantitative reverse-transcription polymerase chain reaction and immunohistochemistry. The impact of NPTXR on the malignant behavior of ESCC was examined using small interfering RNA-mediated knockdown and a subsequent assessment of cell proliferation, apoptosis, and adhesion. This study further investigated the efficacy of anti-NPTXR mAb in vitro and associations between the expression of NPTXR messenger RNA (mRNA) and protein with clinicopathological factors and the prognosis. RESULTS: NPTXR was overexpressed in several ESCC cell lines and primary ESCC tissues. Knockdown of NPTXR in ESCC cells resulted in reduced proliferation, increased apoptosis, and decreased cell adhesion. The mAb against NPTXR significantly inhibited ESCC cell proliferation in vitro. A high NPTXR expression in patient tissues was correlated with a worse overall survival, suggesting its potential as a prognostic biomarker. CONCLUSIONS: NPTXR influences the malignant behavior of ESCC cells. Anti-NPTXR mAb may be a promising therapeutic agent, and its expression in ESCC tissues may serve as a prognostic biomarker.

Financial burden of surgical treatment for retroperitoneal sarcoma.

PURPOSES: The purpose of this study was to compare the financial burden of surgery for retroperitoneal sarcoma (RPS) and gastric cancer (GC). METHODS: All patients who underwent surgery for GC or RPS between 2020 and 2021 at Nagoya University Hospital were included. The clinical characteristics, surgical fees per surgeon, and surgical fees per hour were compared between the two groups. RESULTS: The GC and RPS groups included 35 and 63 patients, respectively. In the latter group, 37 patients (59%) underwent tumor resection combined with organ resection; the most common organ was the intestine (n = 23, 37%), followed by the kidney (n = 16, 25%). The mean operative time (248 vs. 417 min, p < 0.001) and intraoperative blood loss (423 vs. 1123 ml, p < 0.001) were significantly greater in the RPS group than in the GC group. The mean surgical fee per surgeon was USD 1667 in the GC group and USD 1022 in the RPS group (p < 0.001) and USD 1388 and USD 777 per hour, respectively (p < 0.001). CONCLUSIONS: The financial burden of surgical treatment for RPS is unexpectedly higher than that for GC.

Protocol of a phase II study investigating the efficacy and safety of trifluridine/tipiracil plus ramucirumab as a third-line or later treatment for advanced gastric cancer.

In Japan, systemic chemotherapy is the standard treatment for unresectable, advanced, or recurrent gastric cancer. However, numerous patients with gastric cancer do not receive late-line treatment because of the rapid progression of gastric cancer. Additionally, late-line treatments, such as nivolumab, trifluridine tipiracil (FTD/TPI), or irinotecan, have limited effects on improving clinical symptoms and delaying the onset of symptoms associated with cancer progression. Recently, a combination of FTD/TPI and ramucirumab was reported to have a high response rate in late-line treatment; however, owing to patient selection bias and a high rate of hematologic toxicity in that previous study, this regimen may not be feasible in real-world clinical applications. Our objective is to conduct a single-arm phase II study to assess the safety and efficacy of FTD/TPI plus ramucirumab combination therapy for gastric cancer after third-line treatment under real-world clinical conditions. This study will recruit 32 patients according to eligibility criteria and administer FTD/TPI (35 mg/m2) and intravenous ramucirumab (8 mg/kg). The primary endpoint will be the time to treatment failure. The secondary endpoints will include the overall survival time, progression-free survival time, overall response rate, disease control rate, relative dose intensity, and incidence of adverse events. The results will add new insights for improving the late-line treatment of advanced gastric cancer.

Risk Factors for Long-term Body Weight Loss After Proximal Gastrectomy: A Retrospective Analysis.

BACKGROUND/AIM: Proximal gastrectomy (PG) is a therapy for early-stage proximal gastric cancer and offers advantages such as the preservation of food storage capacity and less body weight loss (BWL). Nevertheless, significant BWL following PG may occur, affecting the patient's well-being and survival. In this study, we aimed to identify the relevant factors for BWL following PG by analyzing an institutional database of patients. PATIENTS AND METHODS: We enrolled 58 consecutive patients who underwent PG for gastric or esophagogastric junction cancer at our institution between April 2004 and March 2021. Based on BWL at 12 months postoperatively, we retrospectively compared and examined patient characteristics, surgical details, and nutritional markers. RESULTS: The mean BWL of the 58 patients included in this analysis was 14.0±7.2%. When the patients were divided into BWL-moderate (n=29) and BWL-severe (n=29) groups using a cutoff value of 15.7%, the latter experienced early BWL within 1 month postoperatively, primarily due to body fat mass reduction, with no recovery during the 60 months of follow up. In contrast, gradual recovery was observed among patients in the BWL-moderate group after experiencing the lowest body weight 24 months postoperatively. A greater decrease in body fat mass than in muscle mass was observed in both groups. Blood hemoglobin levels did not recover in the BWL-severe group. CONCLUSION: The BWL-severe group after proximal gastrectomy demonstrated significantly greater early postoperative BWL, primarily attributed to a reduction in body fat mass, with hardly any recovery. Early postoperative nutritional intervention might be proposed to prevent long-term BWL.

Impact of treatment guidelines and pivotal clinical trial results on a surgeon's decision regarding treatment for gastric cancer: a retrospective cohort study using the National Clinical Database.

PURPOSES: The present study evaluated the impact of clinical guidelines for gastric cancer surgery on surgeons' choice of procedure in real-world practice. We focused on the 2014 guideline revision recommending laparoscopic surgery and the evidence concerning splenectomy for prophylactic lymphadenectomy reported in 2015 using the National Clinical Database, which is the most comprehensive database in Japan. METHODS: We investigated the monthly percentages of laparoscopic distal gastrectomies performed for stage I gastric cancer (LDG%) and splenectomies performed during total gastrectomy for advanced cancer (TGS%) between 2014 and 2017. We evaluated the descriptive statistics of the time-series changes in the LDG%, TGS%, and annual trends of outcomes. RESULTS: In total, 124,787 patients were enrolled. The mean LDG% and TGS% were 69.8% and 9.2%, respectively. The LDG% and TGS% were 66.4% and 16.7%, respectively, in January 2014 and 73.1% and 5.9%, respectively, in December 2017. LDG% consistently increased, and TGS% showed a consistent downward trend throughout the observation period. There was no significant change in this trend after the publication of the guideline recommendations or clinical trial results. CONCLUSION: No significant changes in surgical procedures were observed after publication of the guidelines or results of clinical trials.

Killer cell lectin-like receptor G2 facilitates aggressive phenotypes of gastric cancer cells via dual activation of the ERK1/2 and JAK/STAT pathways.

BACKGROUND: Advanced gastric cancer (GC) has a poor prognosis. This study aimed to identify novel GC-related genes as potential therapeutic targets. METHODS: Killer cell lectin-like receptor G2 (KLRG2) was identified as a candidate gene by transcriptome analysis of metastatic GC tissues. Small interfering RNA-mediated KLRG2 knockdown in human GC cell lines was used to investigate KLRG2 involvement in signaling pathways and functional behaviors in vitro and in vivo. Clinicopathological data were analyzed in patients stratified according to tumor KLRG2 mRNA expression. RESULTS: KLRG2 knockdown in GC cells decreased cell proliferation, migration, and invasion; caused cell cycle arrest in G2/M phase; induced apoptosis via caspase activation; suppressed JAK/STAT and MAPK-ERK1/2 pathway activities; and upregulated p53 and p38 MAPK activities. In mouse xenograft models of peritoneal metastasis, the number and weight of disseminated GC nodules were decreased by KLRG2 knockdown. High tumor levels of KLRG2 mRNA were significantly associated with lower 5-year overall survival (OS) and relapse-free survival (RFS) rates in patients with Stage I-III GC (5-year OS rate: 64.4% vs. 80.0%, P = 0.009; 5-year RFS rate: 62.8% vs. 78.1%, P = 0.030). CONCLUSIONS: KLRG2 knockdown attenuated the malignant phenotypes of GC cells via downregulation of JAK/STAT and MAPK-ERK1/2 pathway activity and upregulation of p38 MAPK and p53. Targeted suppression of KLRG2 may serve as a new treatment approach for GC.

Docetaxel, cisplatin, and fluorouracil with pegfilgrastim on day 3 as neoadjuvant chemotherapy for esophageal cancer.

PURPOSE: A high risk of febrile neutropenia (FN) from neoadjuvant chemotherapy with docetaxel, cisplatin, and fluorouracil (DCF) for esophageal cancer has been reported. The optimal timing of prophylactic use of pegfilgrastim remains to be elucidated. To evaluate the effect of pegfilgrastim administered on day 3, we conducted a feasibility study. METHODS: Chemotherapy consisted of intravenous administration of docetaxel (70 mg/m2 per day) and cisplatin (70 mg/m2 per day) on day 1 and continuous infusion of 5-fluorouracil (750 mg/m2 per day) on days 1-5. Pegfilgrastim was given as a single subcutaneous injection at a dose of 3.6 mg on day 3 during each treatment course. This regimen was repeated every 3 weeks for up to a maximum of three courses. Prophylactic antibiotics were not needed but were allowed to be given at the discretion of the physician. The primary endpoint was the incidence of FN. RESULTS: Twenty-six patients were administered DCF in combination with pegfilgrastim on day 3. After the first course of DCF, 10 out of 26 patients (38.5%) experienced grade 4 neutropenia, and two patients (7.7%) experienced FN. Of the 14 patients who did not receive prophylactic antibiotics, four had grade 4 neutropenia, including two who developed FN. On the contrary, of the 12 patients who received prophylactic levofloxacin, six had grade 4 neutropenia, but no cases of FN were observed. CONCLUSION: Administration of pegfilgrastim on day 3 was not sufficient to prevent FN due to DCF treatment, and prophylactic administration of both pegfilgrastim and antibiotics could be a solution.

A multi-institutional prospective observational study to compare postoperative quality of life of patients who undergo total or proximal gastrectomy for early gastric cancer (CCOG1602).

BACKGROUND: Proximal gastrectomy (PG) has become an increasingly preferred procedure for treating early cancer in the upper third of the stomach. However, advantages of PG in postoperative quality of life (QOL) over total gastrectomy (TG) has not fully proven. METHODS: We conducted a multi-institutional prospective observational study (CCOG1602) of patients who undergo TG or PG for cStage I gastric cancer. We used the PGSAS-37 and EORTC-QLQ-C30 to evaluate the changes in body weight and QOL over a 3-year postoperative period. The primary endpoint was the weight loss rate 3 years after surgery. RESULTS: We enrolled 109 patients from 18 institutions and selected 65 and 19 patients for inclusion in the TG and PG groups, respectively. Mean postoperative weight loss rates were 16.0% and 11.7% for the TG and PG groups, respectively (p = 0.056, Cohen's d 0.656) during postoperative year 1% and 15.0% and 10.8% for TG and PG (p = 0.068, Cohen's d 0.543), respectively, during postoperative year 3, indicating that the PG group achieved a better trend with a moderate effect size. According to the PGSAS-37, the PG group experienced a better trend in the indigestion subscale (p < 0.001, Cohen's d -1.085) and total symptom score (p = 0.050, Cohen's d -0.59) during postoperative year 3 compared with the TG group. In contrast, the EORTC-QLQ-C30 detected no difference between the groups at any time point during 3-year postoperative period. CONCLUSIONS: This prospective study demonstrates that PG tended to be more favorable compared with TG with respect to postoperative weight loss and QOL, particularly regarding indigestion.

Absence of Hypercoagulation Status after Neoadjuvant Treatment is Associated with Favorable Prognosis in Patients Undergoing Subtotal Esophagectomy for Esophageal Squamous Cell Carcinoma.

BACKGROUND: Abnormal activation of the coagulation system is associated with malignant tumor progression. Although neoadjuvant treatment (NAT) for resectable esophageal squamous cell carcinoma (ESCC) is the standard of care, the correlation between coagulation status and prognosis of patients undergoing preoperative treatment is insufficiently understood. METHODS: Patients (n = 200) who underwent radical subtotal esophagectomy after preoperative treatment for ESCC between January 2012 and December 2021were included in the analysis. Plasma D-dimer and fibrinogen levels and their combined indices (non-hypercoagulation; D-dimer and fibrinogen levels within the upper normal limit, or hypercoagulation; D-dimer or fibrinogen levels above the upper normal limit) were determined before and after NAT and correlated to clinicopathological factors and prognosis. RESULTS: The nonhypercoagulation group achieved superior overall survival (OS) than the hypercoagulation group (5-year OS rates = 89% vs. 55%; hazard ratio 3.62, P = 0.0008) when determined according to coagulation status after NAT. Multivariate analysis showed that hypercoagulation after NAT served as an independent factor for poor postoperative OS (hazard ratio 3.20; P = 0.0028). The nonhypercoagulation group achieved significantly better disease-free survival (76% vs. 54%; P = 0.0065) than the hypercoagulation group that experienced a significantly higher rate of hematogenous metastasis as an initial recurrence (P = 0.0337). CONCLUSIONS: Hypercoagulation state after NAT served as a valid indicator correlating with postoperative outcomes of patients with ESCC who underwent NAT followed by radical subtotal esophagectomy.

Impact of sarcopenia on biliary drainage during neoadjuvant therapy for pancreatic cancer.

BACKGROUND/AIMS: Since the usefulness of neoadjuvant chemo(radiation) therapy (NAT) for pancreatic cancer has been demonstrated, recurrent biliary obstruction (RBO) in patients with pancreatic cancer with a fully covered self-expandable metal stent (FCSEMS) during NAT is expected to increase. This study investigated the impact of sarcopenia on RBO in this setting. METHODS: Patients were divided into normal and low skeletal muscle index (SMI) groups and retrospectively analyzed. Patient characteristics, overall survival, time to RBO (TRBO), stent-related adverse events, and postoperative complications were compared between the two groups. A Cox proportional hazard model was used to identify the risk factors for short TRBO. RESULTS: A few significant differences were observed in patient characteristics, overall survival, stent-related adverse events, and postoperative complications between 38 patients in the normal SMI group and 17 in the low SMI group. The median TRBO was not reached in the normal SMI group and was 112 days in the low SMI group (p=0.004). In multivariate analysis, low SMI was the only risk factor for short TRBO, with a hazard ratio of 5.707 (95% confidence interval, 1.148-28.381; p=0.033). CONCLUSION: Sarcopenia was identified as an independent risk factor for RBO in patients with pancreatic cancer with FCSEMS during NAT.