Initial validation of the clinical significance of the NETest in Japanese gastroenteropancreatic neuroendocrine tumor patients.

As novel biomarkers for gastroenteropancreatic neuroendocrine tumors (GEPNET) are in demand, we aimed to validate the clinical value of the NETest in Japanese patients. Between 2021 and 2023, blood and clinical data were collected from patients with GEPNET. Among 35 patients (median age: 59 [49-66] years), 27 cases originated from the pancreas and eight from the gastrointestinal tract. Of 69 samples sent to the laboratory, 56 (81.2%) underwent NETest. The diagnostic sensitivity was 97.1%. Among three patients who underwent R0 resection and four treated with peptide receptor radionuclide therapy, the changes in NETest scores closely correlated with disease progression. The NETest demonstrated high diagnostic efficacy and accurate therapeutic monitoring capabilities in a Japanese population.

Distinct clinicopathological features of neuroendocrine liver metastases originating from the pancreas and rectum.

INTRODUCTION: Survival comparisons among patients with liver metastases from pancreatic and rectal neuroendocrine tumors (NETs) were limited, and the efficacy of observation rules in patients undergoing hepatectomy for neuroendocrine liver metastases (NELMs) was unknown. This study aims to distinguish these characteristics and clarify the effects of the observation rules on NELMs. METHODS: Clinical data were separately collected from patients with pancreatic and rectal NELMs at medical centers in both Japan and China. The Japanese cohort followed the observation rules for the resection of NELMs. A comparative analysis was conducted on clinical characteristics and prognosis features such as overall survival time (OS) and disease-free survival interval (DFS-I). RESULTS: Enrollment included 47 and 34 patients from Japan and China, respectively. Of these, 69 and 12 patients had tumors originating from the pancreas and rectum, respectively. The OS time in patients undergoing primary tumor resection was significantly longer; however, the OS time between the patients undergoing and not undergoing radical resection of liver metastasis was the same. In asynchronous NELMs, patients with rectal (R)-NELMs showed a significantly higher proportion of type III NELMs. Additionally, the median DFS-I of asynchronous R-NELMs was longer than the recommended follow-up time, with 71.4% of them classified as G2. In the Japanese cohort, patients who adhered to the observation rules exhibited a longer median DFS after hepatectomy for NELMs compared with their counterparts. CONCLUSION: Although curative surgery is crucial for primary lesions, personalized approaches are required to manage NELMs. Extended overall follow-ups and shortened follow-up intervals are recommended for G2 stage rectal NETs. The observation rules for NELMs require further validation with a larger sample size.

The efficacy of wrapping with polyglycolic acid mesh and fibrin glue in preventing clinically relevant pancreatic fistula after minimally invasive distal pancreatectomy (WRAP Study): study protocol for a multicenter randomized controlled trial in Japan.

BACKGROUND: Postoperative pancreatic fistula (POPF) continues to be the most common complication after distal pancreatectomy (DP). Recent advancements in surgical techniques have established minimally invasive distal pancreatectomy (MIDP) as the standard treatment for various conditions, including pancreatic cancer. However, MIDP has not demonstrated a clear advantage over open DP in terms of POPF rates, indicating the need for additional strategies to prevent POPF in MIDP. This trial (WRAP study) aims to evaluate the efficacy of wrapping the pancreatic stump with polyglycolic acid (PGA) mesh and fibrin glue in preventing clinically relevant (CR-) POPF following MIDP. METHODS: This multicenter, randomized controlled trial will include patients scheduled for laparoscopic or robotic DP for tumors in the pancreatic body and/or tail. Eligible participants will be centrally randomized into either the control group (Group A) or the intervention group (Group B), where the pancreatic stump will be reinforced by PGA mesh and fibrin glue. In both groups, pancreatic transection will be performed using a bioabsorbable reinforcement-attached stapler. A total of 172 patients will be enrolled across 14 high-volume centers in Japan. The primary endpoint is the incidence of CR-POPF (International Study Group of Pancreatic Surgery grade B/C). DISCUSSION: The WRAP study will determine whether the reinforcement of the pancreatic stump with PGA mesh and fibrin glue, a technique whose utility has been previously debated, could become the best practice in the era of MIDP, thereby enhancing its safety. TRIAL REGISTRATION: This trial was registered with the Japan Registry of Clinical Trials on June 15, 2024 (jRCTs032240120).

The key role of calreticulin in immunomodulation induced by chemotherapeutic agents.

BACKGROUND: It has recently been shown that certain chemotherapeutic agents can improve host immune responses. The present study aimed to demonstrate the mechanism by which chemotherapeutic agents modify the tumor microenvironment and induce tumor-specific immune responses. METHODS: Three mouse cancer cell lines [CT26 mouse colon cancer cells, B16 melanoma cells and Lewis lung carcinoma (LLC)], 5 human carcinoma cell lines (human esophageal squamous cell carcinoma cell lines TE8 and HEC46 and the human pancreatic carcinoma cell lines PK-9, AsPC-1 and SUIT-2) and 5 chemotherapeutic agents [mitoxantrone (MIT), mitomycin C(MMC), 5-fluorouracil (5FU), camptothecin (CPT-11) and cisplatin (CDDP)] that are frequently used in a clinical setting for cancer treatment were utilized to investigate the surface expression level of calreticulin and HLA class I after exposure to chemotherapeutic agents. RESULTS: Increased calreticulin (CRT) expression on the surface of mouse cell lines and, moreover, increased surface expression levels of both CRT and HLA class I in all human cell lines were observed in cells treated by the chemotherapeutic agents as compared with non-treated cells. The surface expression level of CRT was significantly correlated with the HLA class I expression level in all human cell lines. CONCLUSIONS: In conclusion, chemotherapeutic drugs can improve the immunogenicity of cancer cells in a cell-specific manner through the mechanism of translocation of CRT.

Perioperative chemotherapy with nivolumab for HER2-negative locally advanced gastric cancer: a case series.

BACKGROUND: Nivolumab with chemotherapy has been transformative for metastatic gastric cancer (GC). The potential of this regimen for local tumor control could be utilized for perioperative chemotherapy in locally advanced GC with bulky tumors or lymph node metastasis involving other organs. CASE PRESENTATION: Five patients with HER2-negative advanced GC were treated with nivolumab and oxaliplatin-based chemotherapy. All patients presented with clinical stage III or IVA GC with tumors in contact with either the pancreas or liver. Following chemotherapy, all tumors demonstrated shrinkage, allowing successful radical gastrectomies including four minimally invasive approach without postoperative complications. Four patients avoided combined resection of other organs. CONCLUSIONS: Perioperative chemotherapy with nivolumab was effective for local disease control in this case series. This regimen could be a promising treatment approach for locally advanced GC; however, its survival benefits should be evaluated in clinical trials.

A Case of Loss of Consciousness Due to Thrombosis of the Inferior Vena Cava and Portal Vein.

We present a case where intraperitoneal venous thrombosis was difficult to treat. It is difficult to suspect intraperitoneal venous thrombosis in patients who have visited the hospital due to loss of consciousness, and it is necessary to administer anticoagulants early for treatment and to determine the appropriate timing for surgical intervention. The patient was a 78-year-old male who independently performed his daily activities. On the day of admission, he lost consciousness and was brought to our hospital. Computed tomography (CT) angiography revealed thrombi from the inferior vena cava and portal vein to the superior mesenteric vein, and the patient was started on anticoagulant therapy. The CT angiography images on day 7 of the illness revealed that the thrombus in the superior mesenteric vein expanded to the caudal side. Intestinal necrosis occurred on day 22 of the illness, and emergency laparotomy was performed. The chosen course of treatment was successful, and the patient was discharged on the 48th day.

Preoperative embolization strategy for the combined resection of replaced right hepatic artery in pancreaticoduodenectomy: a small case series.

BACKGROUND: Replaced right hepatic artery (rRHA) is a common vascular variation, and combined resection of this vessel is sometimes needed for the curative resection of pancreatic head malignancy. Safe surgical management has not been established, and there is a small number of reported cases. Here, we reported five cases, wherein preoperative embolization of rRHA was performed for combined resection. CASE PRESENTATION: All patients had pancreatic head malignancies that were in contact with rRHA. We performed a preoperative embolization of the rRHA before the scheduled pancreaticoduodenectomy for the combined resection. Arterial embolization was safely accomplished, and the communicating arcade from the left hepatic artery via the hilar plate was clearly revealed in all cases. Four patients underwent the operative procedure, except for one patient who had liver metastasis at laparotomy. No patient suffered from a severe abnormal liver function during the management; however, one patient had multiple liver infarctions during the postoperative course. CONCLUSIONS: Preoperative embolization for the combined resection of rRHA in pancreaticoduodenectomy can be a management option for the precise evaluation of hemodynamics after sacrificing rRHA. In our cases, arterial flow to the right liver lobe was supplied by the left hepatic artery via the bypass route, including the communicating arcade of the hilar plate.

Efficacy and Long-term Peripheral Sensory Neuropathy of 3 vs 6 Months of Oxaliplatin-Based Adjuvant Chemotherapy for Colon Cancer: The ACHIEVE Phase 3 Randomized Clinical Trial.

Importance: Oxaliplatin-based chemotherapy is associated with debilitating peripheral sensory neuropathy (PSN) for patients with stage III colon cancer. Objective: To assess disease-free survival (DFS) and long-lasting PSN in patients treated with 3 vs 6 months of adjuvant oxaliplatin-based chemotherapy. Design, Setting, and Participants: An open-label, multicenter, phase 3 randomized clinical trial of 1313 Asian patients with stage III colon cancer was conducted investigating the noninferiority of 3 vs 6 months of adjuvant oxaliplatin-based chemotherapy. From August 1, 2012, to June 30, 2014, participants were randomized to the 2 treatment groups. Data were analyzed from July 2017 to June 2018. Interventions: Patients were randomized to receive 3 or 6 months of adjuvant chemotherapy. The choice of chemotherapy regimen, with the drugs modified fluorouracil, leucovorin, and oxaliplatin (mFOLFOX6) or capecitabine plus oxaliplatin (CAPOX), was at the discretion of the treating physician. Main Outcomes and Measures: The primary outcome was DFS. Secondary end points included the evaluation of PSN for up to 3 years and overall survival. Results: Of the 1313 patients (651 were women and mean age was 66 [range, 28-85] years) enrolled and randomized, 22 were not treated because 10 were unable to begin treatment within 2 weeks of enrollment, 7 withdrew their consent, and 5 were not treated for various other reasons. Of 1291 patients treated (650 in the 3-month arm and 641 in the 6-month arm), 969 (75%) received the chemotherapy drug CAPOX. The hazard ratio (HR) for DFS of the 3-month arm compared with the 6-month arm was 0.95 (95% CI, 0.76-1.20). Hazard ratios were 1.07 (95% CI, 0.71-1.60) and 0.90 (95% CI, 0.68-1.20) for the drugs mFOLFOX6 and CAPOX, and 0.81 (95% CI, 0.53-1.24) and 1.07 (95% CI, 0.81-1.40) for patients with low-risk disease (TNM classification stages T1-3 and N1) and high-risk disease (stages T4 or N2), respectively. The rates of any grade of PSN lasting for 3 years in the 3-month vs 6-month treatment arms were 9.7% vs 24.3% (P < .001). Incidence of PSN lasting for 3 years was significantly lower for patients treated with CAPOX than for patients treated with mFOLFOX6 in both the 3-month (7.9% vs 15.7%; P = .04) and 6-month arms (21.0% vs 34.1%; P = .02). Conclusions and Relevance: The incidence of long-lasting PSN was significantly lower for 3 months than for 6 months of therapy, and significantly lower for treatment with the drug CAPOX than with mFOLFOX6. Since the shortened therapy duration did not compromise outcomes, a 3-month course of CAPOX may be the most appropriate treatment option, particularly for patients with low-risk disease. Trial Registration: UMIN Clinical Trials Registry: UMIN000008543.

Laparoscopic repair with cone-shaped mesh implantation for perineal hernia occurred after laparoscopic abdominoperineal resection.

INTRODUCTION: Perineal hernia after abdominoperineal resection (APR) is a rare complication, and no standard surgical procedures are established. We describe a simple laparoscopic mesh implantation technique utilizing a large synthetic flat mesh. PRESENTATION OF CASE: We report a case of perineal hernia after APR. We performed laparoscopic repair using a soft and large synthetic mesh with simple technique. The essence of this technique is that mesh is inserted into the abdominal cavity without trimming and it forms in a conical shape to better adjust to the pelvic cavity. DISCUSSION: The perineal and laparoscopic approaches for perineal hernia repair have been performed most commonly in recent years, but the recurrence rate after repair remains high (24.1%). Using a large mesh could cover the hernial orifice with a sufficient margin, reducing a risk of recurrence caused by shrinkage and slippage of the mesh. CONCLUSION: Our technique utilizing a large, lightweight, synthetic mesh can be practical and useful for perineal hernia repair after laparoscopic APR.

Clinical Implications of CD4+CD25+Foxp3+Regulatory T Cell Frequencies After CHP-MAGE-A4 Cancer Vaccination.

BACKGROUND/AIM: The aim of this study was to explore whether the treatment effect or immune response to a cancer vaccine can be predicted by the percentage of CD4+CD25+Foxp3+ regulatory T cells (Tregs) in peripheral blood mononuclear cells (PBMCs) after vaccination. PATIENTS AND METHODS: Sixteen patients (9 men, 7 women; median age 61.5 years) enrolled in the CHP-MAGE-A4 cancer vaccine clinical trial who had a fixed dose (300 µg of CHP-MAGE-A4 cancer vaccine and 0.5 Klinische Einheit (KE) of OK432 and received at least four vaccinations were investigated. Safety, immune response, and clinical effects were assessed before and after the cancer vaccination. RESULTS: Treg ratios that remained low both before and after vaccination were associated with a good prognosis, and a low Treg/CD4 lymphocyte ratio 7-weeks after the initial vaccination was correlated with a better prognosis. CONCLUSION: The Treg ratio following vaccination appears to have some utility for predicting patient prognosis.

Pathological complete response of locally advanced colon cancer after preoperative radiotherapy: a case report and narrative review of the literature.

BACKGROUND: The oncological effectiveness of preoperative radiotherapy for locally advanced colon cancer is unclear. We report a case of pathological complete response in a patient with locally advanced ascending colon cancer after preoperative radiotherapy following failure of chemotherapy. CASE PRESENTATION: A 65-year-old Japanese woman presented with malaise and hematochezia. A computed tomography (CT) revealed a tumor in the ascending colon which seemed to infiltrate the adjacent structures. She was diagnosed with locally advanced ascending colon cancer stages T4b, N2a, M0, and IIIC. We selected modified FOLFOX6 with panitumumab as neoadjuvant chemotherapy. However, we discontinued the chemotherapy after the 8th cycle because of disease progression and severe adverse effects. The patient then underwent radiotherapy of 60 Gy in 30 fractions, resulting in significant tumor size reduction. One month after the radiotherapy, we performed a right hemicolectomy with multivisceral resection without complications. Histopathologically, we found no residual cancer cells in the resected specimen. The patient remains alive and has not required additional therapies for 24 months, as there are no signs of recurrence. CONCLUSIONS: The present case suggests that preoperative radiotherapy might be an effective treatment options for locally advanced colon cancer.

Therapeutic activity of retroviral replicating vector-mediated prodrug activator gene therapy for pancreatic cancer.

Toca 511, a retroviral replicating vector (RRV) encoding the yeast cytosine deaminase (yCD) prodrug activator gene, which mediates conversion of the prodrug 5-fluorocytosine (5-FC) to the anticancer drug 5-fluorouracil (5-FU), is currently being evaluated in Phase II/III clinical trials for glioma, and showing highly promising evidence of therapeutic activity. Here we evaluated RRV-mediated prodrug activator gene therapy as a new therapeutic approach for pancreatic ductal adenocarcinoma (PDAC). RRV spread rapidly and conferred significant cytotoxicity with prodrug in a panel of PDAC cells. Efficient intratumoral replication and complete inhibition of tumor growth upon 5-FC administration were observed in both immunodeficient and immunocompetent subcutaneous PDAC models. Biodistribution of RRV was highly restricted in normal tissues, especially in immunocompetent hosts. Tumor growth inhibition by Toca 511 followed by 5-FC was also confirmed in the orthotopic PDAC model. This study provides the first proof-of-concept for application of Toca 511 and Toca FC (extended release 5-FC) to the treatment of human PDAC, and provided support for inclusion of PDAC in a Phase I study evaluating Toca 511 in various systemic malignancies, (NCT02576665), which has recently been initiated.

Molecular targeting of cell-permeable peptide inhibits pancreatic ductal adenocarcinoma cell proliferation.

BACKGROUND: Chromosome 16 open reading frame 74 (C16orf74) is highly expressed in pancreatic ductal adenocarcinoma (PDAC) and is involved in cancer cell proliferation and invasion through binding to calcineurin (CN). Therefore, C16orf74 is a good target for the development of a PDAC treatment. A cell-permeable dominant-negative (DN) peptide that can inhibit the C16orf74/CN interaction was designed to examine whether this peptide can inhibit PDAC cell proliferation in vitro and in vivo. METHOD: TheDN-C16orf74 peptide, which corresponds to the portion of C16orf74 that interacts with CN, was synthesized, and we assessed its anti-tumor activity in proliferation assays with human PDAC cells and the underlying molecular signaling pathway. Using an orthotopic xenograft model of PDAC, we treated mice intraperitoneally with phosphate-buffered saline (PBS), control peptide, or DN-C16orf74 and analyzed the tumor-suppressive effects. RESULT: DN-C16orf74 inhibited the binding of C16orf74 to CN in an immunoprecipitation assay. DN-C16orf74 suppressed PDAC cell proliferation, and the level of suppression depended on the expression levels of C16orf74 in vitro. DN-C16orf74 also exhibited anti-tumor effects in orthotopic xenograft model. Furthermore, the tumor-suppressive effect was associated with inhibition of the phosphorylation of Akt and mTOR. CONCLUSION: The cell-permeable peptide DN-C16orf74 has a strong anti-tumor effect against PDAC in vitro and in vivo.

Clinical impact of chemotherapy to improve tumor microenvironment of pancreatic cancer.

A perioperative multimodal strategy including combination chemotherapy and radiotherapy, in addition to surgical resection, has been acknowledged to improve patient prognosis. However chemotherapy has not been actively applied as an immunomodulating modality because of concerns about various immunosuppressive effects. It has recently been shown that certain chemotherapeutic agents could modify tumor microenvironment and host immune responses through several underlying mechanisms such as immunogenic cell death, local T-cell infiltration and also the eradication of immune-suppressing regulatory cells such as regulatory T cells (Tregs) and myeloid-derived suppressor cells. With the better understanding of the cell components in the tumor microenvironment and the effect of chemotherapy to improve tumor microenvironment, it has been gradually clear that the chemotherapeutic agents is two-edged sword to have both immune promoting and suppressing effects. The cellular components of the tumor microenvironment include infiltrating T lymphocytes, dendritic cells, regulatory T cells, tumor associated macrophages, myeloid derived suppressor cells and cancer associated fibroblasts. Based on the better understanding of tumor microenvironment following chemotherapy, the treatment protocol could be modified as personalized medicine and the prognosis of pancreas cancer would be more improved utilizing multimodal chemotherapy. Here we review the recent advances of chemotherapy to improve tumor microenvironment of pancreatic cancer, introducing the unique feature of tumor microenvironment of pancreatic cancer, interaction between anti-cancer reagents and these constituting cells and future prospects.

Inhibition of Eph receptor A4 by 2,5-dimethylpyrrolyl benzoic acid suppresses human pancreatic cancer growing orthotopically in nude mice.

Ephrin receptor A4 (EphA4) is overexpressed in human pancreatic adenocarcinoma (PDAC) and activate cell growth. Recent studies have identified small molecules that block EphA4. In this study, we investigated the correlation between EphA4 expression and the prognosis of patients with PDAC. We also examined the cytostatic efficacy of 2,5-dimethylpyrrolyl benzoic acid (compound 1), a small molecule that blocks EphA4, in PDAC cells. Overall survival of patients with EphA4 positivity was significantly shorter than that of patients with EphA4 negativity (P = 0.029). In addition, multivariate analysis revealed that EphA4 expression was an independent prognostic factor in PDAC patients (P = 0.039). Compound 1 showed a cytostatic efficacy in PDAC cells expressing EphA4 in vitro and in vivo. Our study indicated that compound 1 suppressed both EphA4 and Akt phosphorylations, and induced apoptosis in PDAC cells expressing EphA4. In conclusion, compound 1 has a high potential as a therapeutic agent for patients with PDAC.

Chemotherapy-Derived Inflammatory Responses Accelerate the Formation of Immunosuppressive Myeloid Cells in the Tissue Microenvironment of Human Pancreatic Cancer.

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic malignancies. PDAC builds a tumor microenvironment that plays critical roles in tumor progression and metastasis. However, the relationship between chemotherapy and modulation of PDAC-induced tumor microenvironment remains poorly understood. In this study, we report a role of chemotherapy-derived inflammatory response in the enrichment of PDAC microenvironment with immunosuppressive myeloid cells. Granulocyte macrophage colony-stimulating factor (GM-CSF) is a major cytokine associated with oncogenic KRAS in PDAC cells. GM-CSF production was significantly enhanced in various PDAC cell lines or PDAC tumor tissues from patients after treatment with chemotherapy, which induced the differentiation of monocytes into myeloid-derived suppressor cells (MDSC). Furthermore, blockade of GM-CSF with monoclonal antibodies helped to restore T-cell proliferation when cocultured with monocytes stimulated with tumor supernatants. GM-CSF expression was also observed in primary tumors and correlated with poor prognosis in PDAC patients. Together, these results describe a role of GM-CSF in the modification of chemotherapy-treated PDAC microenvironment and suggest that the targeting of GM-CSF may benefit PDAC patients' refractory to current anticancer regimens by defeating MDSC-mediated immune escape.

Blocking monoclonal antibodies of TIM proteins as orchestrators of anti-tumor immune response.

Monoclonal antibody (mAb)-based treatment of cancer has a significant effect on current practice in medical oncology, and is considered now as one of the most successful therapeutic strategies for cancer treatment. MAbs are designed to initiate or enhance anti-tumor immune responses, which can be achieved by either blocking inhibitory immune checkpoint molecules or triggering activating receptors. TIM gene family members are type-I surface molecules expressed in immune cells, and play important roles in the regulation of both innate and adaptive arms of the immune system. Therapeutic strategies based on anti-TIMs mAbs have shown promising results in experimental tumor models, and synergistic combinations of anti-TIMs mAbs with cancer vaccines, adoptive T-cell therapy, radiotherapy and chemotherapy will have great impact on cancer treatment in future clinical development.