Evaluation of ventral branches of segment VI portal vein relative to the right hepatic vein in laparoscopic right anterior sectionectomy.

INTRODUCTION: The right intersectional plane and the right hepatic hilum were noted too often exhibit anatomical variations, making difficult the laparoscopic right anterior sectionectomy (LRAS). METHODS: We analyzed the anatomical features employing 3D-CT images of 55 patients, and evaluated these features according to the course of ventral branches of segment VI of the portal vein (PV, P6a) relative to the right hepatic vein (RHV). RESULTS: P6a run on the dorsal side of RHV in 32 patients (58%, Dorsal-P6a) and the ventral side of RHV in 23 (42%, Ventral-P6a). Ventral-P6a had more patients with S6 partially drained by middle hepatic vein (MHV, 39% vs. 0%, P < 0001), the narrower angle between the anterior and posterior branches of PV (73.1° vs. 93.8°, P = 0.006), the wider angle between the RHV and inferior vena cava  (54.3° vs. 44.3°, P < 0.001), and more steeply pitched angle between S6 and S7 along the RHV (140.6° vs. 162.0°, P < 0.001) compared to Dorsal-P6a. CONCLUSION: In LRAS for Dorsal-P6a patients, the transection surface was relatively flat. In LRAS for Ventral-P6a patients, the narrow space between anterior and posterior glissons makes difficult the glissonean approach. The transection plane was steeply pitched, and RHV was partially exposed. S6 was often partially drained to MHV in 39% of the Ventral-P6a patients, which triggers congestion during liver transection of a right intersectional plane after first splitting the confluence of this branch.

Does Neoadjuvant Chemoradiotherapy Have an Additional Effect to Lateral Pelvic Lymph Node Dissection for Rectal Cancer?

Objectives: A total mesenteric excision (TME) with lateral pelvic lymph node dissection (LLND) is the standard treatment for advanced low rectal cancer in Japan. Recently, neoadjuvant (chemo)radiotherapy (n(C)RT) has been used with LLND to improve outcomes at multiple Japanese institutes. This study evaluates the benefits of adding nCRT to TME with LLND. Methods: Seventy-two consecutive patients who underwent TME and LLND with or without nCRT between 2006-2019 to treat advanced low rectal cancer were retrospectively reviewed. The clinicopathological data were compared and the risk factors for local recurrence were evaluated. Results: Fifty-seven patients (79.1%) underwent TME and LLND with nCRT, and 15 patients (20.9%) without nCRT. There was no significant difference in the clinicopathological characteristics except the clinical T stage. The occurrence of postoperative complications was statistically insignificant. The 5-year local recurrence rate of patients with nCRT was significantly lower than those without (4.0% versus 26.6%, in all patients, p=0.002). Multivariate analysis revealed that the absence of nCRT was an independent risk factor for local recurrences in patients who underwent TME with LLND (hazard ratio: 6.04, p=0.04). Conclusions: The administration of nCRT prevented local recurrences more effectively in patients with advanced low rectal cancer who underwent TME with LLND.

Risk assessment for pancreatic fistula by intraoperative image analysis of laparoscopic and robotic gastrectomy.

BACKGROUND: Pancreatic fistula (PF) is one of the most serious postoperative complications of gastrectomy. Misidentification of the boundary between the pancreas and the dissected fat is a primary concern. In this study, we focused on differences in the appearance of the pancreas and the dissected fat in actual surgical images and statistically analyzed the relationship between the pancreas and the dissected fat. METHODS: We analyzed data from 109 gastric cancer patients who underwent curative gastrectomy between November 2018 and March 2023. Intraoperative images were taken from videos of lymph node dissections of Nos.6 and 8a regions, and the mean gray value of the areas was measured using ImageJ software for analysis. The visceral fat area (VFA) was evaluated by preoperative axial CT at the umbilical level using Ziostation software. RESULTS: A significant correlation was observed between the fat/pancreas gray value ratio in the No.8a lymph node region and the drain/serum amylase ratio (P < 0.001). The fat/pancreas gray value ratio in the No.6 lymph node region correlated with VFA (P < 0.001). The VFA and drain/serum amylase ratio were significantly higher in the group with intra-abdominal complications (P = 0.004). CONCLUSIONS: We revealed significant relationships between the fat/pancreas gray value ratio with drain/serum amylase and VFA. Detecting differences in gray values between the pancreas and the dissected fat may lead to a decrease in the drain/serum amylase ratio and PF.

Risk factors for liver dysfunction and their clinical importance after gastric cancer surgery.

Postoperative hepatobiliary enzyme abnormalities often present as postoperative liver dysfunction in patients with gastric cancer (GC). This study aimed to identify the risk factors for postoperative liver dysfunction and their clinical impact after GC surgery. We retrospectively analyzed the data of 124 patients with GC who underwent laparoscopic or robotic surgery at Kyoto Prefectural University of Medicine between 2017 and 2019. Twenty (16.1%) patients with GC developed postoperative liver dysfunction (Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 ≥ Grade 3). Univariate analyses identified robotic surgery as a risk factor for postoperative liver dysfunction (P = 0.005). There was no correlation between the postoperative liver dysfunction status and postoperative complications or postoperative hospital stays. Patients with postoperative liver dysfunction did not have significantly worse overall survival (P = 0.296) or recurrence-free survival (P = 0.565) than those without postoperative liver dysfunction. Robotic surgery is a risk factor for postoperative liver dysfunction; however, postoperative liver dysfunction does not affect short or long-term outcomes.

Lymphovascular invasion is associated with poor long-term outcomes in patients with pT1N0-3 or pT2-3N0 remnant gastric cancer: a retrospective cohort study.

BACKGROUND: Lymphovascular invasion (LVI) is a poor prognostic factor in various malignancies. However, its prognostic effect in remnant gastric cancer (RGC) remains unclear. We examined the correlation between LVI and disease prognosis in patients with T1N0-3 or T2-3N0 RGC in whom adjuvant chemotherapy was not indicated and a treatment strategy was not established. METHODS: We retrospectively analyzed patients with T1N0-3 and T2-3N0 RGC who underwent curative surgery at the Kyoto Prefectural University of Medicine between 1997 and 2019 and at the Kyoto Chubu Medical Center between 2009 and 2019. RESULTS: Fifteen of 38 patients (39.5%) with RGC were positive for LVI. Patients with LVI had a significantly poorer prognosis for both overall survival ([OS]: P = 0.006) and recurrence-free survival ([RFS]: P = 0.001) than those without LVI. Multivariate analyses using the Cox proportional hazards model revealed LVI as an independent prognostic factor affecting OS (P = 0.024; hazard ratio 8.27, 95% confidence interval:1.285-161.6) and RFS (P = 0.013; hazard ratio 8.98, 95% confidence interval:1.513-171.2). CONCLUSIONS: LVI is a prognostic factor for patients with T1N0-3 or T2-3N0 RGC. Evaluating LVI may be useful for determining treatment strategies for RGC.

CACNA2D1 regulates the progression and influences the microenvironment of colon cancer.

BACKGROUND: Calcium voltage-gated channel auxiliary subunit alpha 2/delta 1 (CACNA2D1), a gene encoding a voltage-gated calcium channel, has been reported as an oncogene in several cancers. However, its role in colon cancer (CC) remains unclear. This study aimed to investigate the function of CACNA2D1 and its effect on the microenvironment in CC. METHODS: Immunohistochemistry (IHC) analysis was performed on samples collected from 200 patients with CC who underwent curative colectomy. Knockdown experiments were performed using CACNA2D1 siRNA in the human CC cell lines HCT116 and RKO, and cell proliferation, cycle, apoptosis, and migration were then analyzed. The fibroblast cell line CCD-18Co was co-cultured with CC cell lines to determine the effect of CACNA2D1 on fibroblasts and the relationship between CACNA2D1 and the cancer microenvironment. Gene expression profiles of cells were analyzed using microarray analysis. RESULTS: IHC revealed that high CACNA2D1 expression was an independent poor prognostic factor in patients with CC and that CACNA2D1 expression and the stroma are correlated. CACNA2D1 depletion decreased cell proliferation and migration; CACNA2D1 knockdown increased the number of cells in the sub-G1 phase and induced apoptosis. CCD-18Co and HCT116 or RKO cell co-culture revealed that CACNA2D1 affects the cancer microenvironment via fibroblast regulation. Furthermore, microarray analysis showed that the p53 signaling pathway and epithelial-mesenchymal transition-associated pathways were enhanced in CACNA2D1-depleted HCT116 cells. CONCLUSIONS: CACNA2D1 plays an important role in the progression and the microenvironment of CC by regulating fibroblasts and may act as a biomarker for disease progression and a therapeutic target for CC.

Impact of hypoglycemia after gastrectomy on Global Leader Initiative on Malnutrition-defined malnutrition: a retrospective study.

PURPOSE: The Global Leader Initiative on Malnutrition (GLIM) criteria were developed in 2018 as a global indicator of malnutrition, and the term 'malnutrition-sarcopenia syndrome' was established. Recently, it has been reported that fluctuations in blood glucose are related to sarcopenia. In this study, we investigated the effects of glucose fluctuations on malnutrition after gastrectomy using a continuous glucose monitoring (CGM) device. METHODS: We analyzed the data of 69 patients with gastric cancer (GC) who underwent curative gastrectomy between November 2017 and December 2020. CGM was performed over a 2-week period at 1 month and 1 year after surgery. The GLIM criteria included weight loss, the body mass index (BMI), and the psoas muscle mass index (PMI). RESULTS: One year after surgery, 25 and 35 patients had severe and moderate malnutrition, respectively. The time below range (TBR) (percent of time the glucose concentration was < 70 mg/dL) and nocturnal (00:00-06:00) TBR were significantly higher in the severe malnutrition group than in the other groups (TBR: normal/moderate 17.9% vs. severe 21.6%, P = 0.039, nocturnal TBR; normal/moderate 30.6% vs. severe 41.1%, P = 0.034). CONCLUSIONS: Post-gastrectomy hypoglycemia, including long nocturnal hypoglycemia, was higher in severely malnourished patients than in other patients even 1 year after surgery. Prevention of nocturnal hypoglycemia may be the key to improving malnutrition following gastrectomy.

Low blood level of tumour suppressor miR-5193 as a target of immunotherapy to PD-L1 in gastric cancer.

BACKGROUND: Recent studies have identified that low levels of some tumour suppressor microRNAs (miRNAs) in the blood contribute to tumour progression and poor outcomes in various cancers. However, no study has proved these miRNAs are associated with cancer immune mechanisms. METHODS: From a systematic review of the NCBI and miRNA databases, four tumour suppressor miRNA candidates were selected (miR-5193, miR-4443, miR-520h, miR-496) that putatively target programmed cell death ligand 1 (PD-L1). RESULTS: Test-scale and large-scale analyses revealed that plasma levels of miR-5193 were significantly lower in gastric cancer (GC) patients than in healthy volunteers (HVs). Low plasma levels of miR-5193 were associated with advanced pathological stages and were an independent prognostic factor. Overexpression of miR-5193 in GC cells suppressed PD-L1 on the surface of GC cells, even with IFN-γ stimulation. In the coculture model of GC cells and T cells stimulated by anti-CD3/anti-CD28 beads, overexpression of miR-5193 increased anti-tumour activity of T cells by suppressing PD-L1 expression. Subcutaneous injection of miR-5193 also significantly enhanced the tumour-killing activity and trafficking of T cells in mice. CONCLUSIONS: Low blood levels of miR-5193 are associated with GC progression and poor outcomes and could be a target of nucleic acid immunotherapy in GC patients.

Depletion of DNTTIP2 Induces Cell Cycle Arrest in Pancreatic Cancer Cells.

BACKGROUND/AIM: Pancreatic cancer is one of the most lethal malignant cancers worldwide and the seventh most common cause of cancer-related death in both sexes. Herein, we analyzed open access data and discovered that expression of a gene called deoxynucleotidyltransferase terminal-interacting protein 2 (DNTTIP2) is linked to prognosis of pancreatic ductal adenocarcinoma (PDAC). We then elucidated the role of DNTTIP2 in the proliferation of pancreatic cancer cells in vitro. MATERIALS AND METHODS: A WST-8 assay, cell cycle analysis, Annexin-V staining, quantitative reverse transcription-PCR, and western blot analysis were conducted to assess cell proliferation, cell cycle, apoptosis, and expression of DNTTIP2 mRNA and protein, respectively, in DNTTIP2-depleteted MIA-PaCa-2 and PK-1 cells. RESULTS: Depletion of DNTTIP2 induced G1 arrest in MIA-PaCa-2 cells by decreasing expression of special AT-rich sequence binding protein 1 (SATB1) and cyclin-dependent kinase 6 (CDK6). In addition, depletion of DNTTIP2 induced G2 arrest in PK-1 cells by decreasing expression of CDK1. Depletion of DNTTIP2 did not induce apoptosis in MIA-PaCa-2 or PK-1 cells. CONCLUSION: DNTTIP2 is involved in proliferation of pancreatic cancer cells. Thus, DNTTIP2 is a potential target for inhibiting progression of pancreatic cancers.

A shorter distal resection margin is a surrogate marker of nodal metastasis and poor prognosis in distal gastrectomy for advanced gastric cancer.

BACKGROUND: Although a 3-5 cm surgical margin distance is recommended for advanced gastric cancer (GC) in Japanese guidelines, little is known about the clinical effects of the surgical margin, especially the distal resection margin (DM). This study aims to clarify the clinical significance of DM in GC. METHODS: A total of 415 GC patients who underwent curative distal gastrectomy between 2008 and 2018 were analyzed retrospectively. RESULTS: The DM significantly stratified recurrence-free survival (P = 0.002), and a DM < 30 mm was an independent factor of a poor prognosis (P = 0.023, hazard ratio: 1.91). Lymphatic recurrence occurred significantly more frequently in the DM < 30 mm group than in the DM ≥ 30 mm group (P = 0.019, 6.9% vs. 1.9%). Regarding the station No.6 lymph node metastases in advanced GC (DM < 30 mm vs. 30 mm ≤ DM ≤ 50 mm vs. DM > 50 mm), the number (P < 0.001, 1.42 ± 1.69 vs. 1.18 ± 1.80 vs. 0.18 ± 0.64), the positive rate (P < 0.001, 59.0% vs. 46.7% vs. 11.3%) and therapeutic value index (43.3 vs. 14.5 vs. 8.0) were significantly higher in the DM < 30 mm group. By subdivision using the DM distance of 30 mm, more segmented prognostic stratifications were possible (P < 0.001). CONCLUSIONS: A DM of less than 30 mm could be a surrogate marker of poor RFS, especially increasing nodal recurrence. More intensive treatment strategies, including lymphadenectomy and chemotherapy, are needed for patients with this condition.

Cancer Stem Cells of Hepatocellular Carcinoma Are Suppressed by the Voltage-gated Calcium Channel Inhibitor Amlodipine.

BACKGROUND/AIM: The membrane transporters activated in cancer stem cells (CSCs) are the target of novel cancer therapies for hepatocellular carcinoma (HCC). The present investigation demonstrated the expression profiles of ion channels in CSCs of HCC. MATERIALS AND METHODS: Cells that highly expressed aldehyde dehydrogenase 1 family member A1 (ALDH1A1) were separated from HepG2 cells, a human HCC cell line, by fluorescence-activated cell sorting, and CSCs were identified based on the formation of tumorspheres. Gene expression profiles in CSCs were investigated using microarray analysis. RESULTS: Among HepG2 cells, ALDH1A1 messenger RNA level was higher in CSCs than in non-CSCs. Furthermore, CSCs exhibited resistance to cisplatin and had the capacity to redifferentiate. The results of the microarray analysis of CSCs showed the up-regulated expression of several genes related to ion channels, such as calcium voltage-gated channel auxiliary subunit gamma 4 (CACNG4). The cytotoxicity of the CACNG4 inhibitor amlodipine was higher at lower concentrations in CSCs than in non-CSCs, and markedly decreased the number of tumorspheres. The cell population among HepG2 cells that highly expressed ALDH1A1 was also significantly reduced by this inhibitor. CONCLUSION: CACNG4 plays a role in maintaining CSCs, and its inhibitor, amlodipine, could potentially be a targeted therapeutic agent against HCC.

[Identification of ion channel/transporter expression profiles in digestive cancer stem cells for novel targeting therapy].

Recent evidence suggests that the targeting of membrane transporters specifically activated in cancer stem cells (CSCs) is an important strategy for cancer therapy. The objectives of the present study were to investigate the ion channel expression profiles in digestive CSCs. Cells strongly expressing CSC markers, such as ALDH1A1 and CD44, were separated from the human esophageal squamous cell carcinoma, gastric cancer, and pancreatic cancer cell lines using fluorescence-activated cell sorting, and CSCs were identified based on tumorsphere formation. Messenger RNA levels of CSC markers were higher in CSCs than in non-CSCs. These CSCs also exhibited resistance to anticancer agents. The microarray analysis revealed that the expression of transient receptor potential vanilloid 2 (TRPV2), voltage-gated calcium channels (VGCCs), and voltage-gated potassium channels (VGKCs) were upregulated in esophageal, gastric, and pancreatic CSCs, respectively, compared with non-CSCs. The TRPV2 inhibitor tranilast, VGCCs inhibitors amlodipine and verapamil, and VGKC inhibitor 4-aminopyridine exhibited greater cytotoxicity in CSCs compared with non-CSCs, and their inhibitory effects were also confirmed in a xenograft model in nude mice. Taking these results, phase I/II study to investigate clinical safety and efficacy of neoadjuvant combination chemotherapy of tranilast in advanced esophageal squamous cell carcinoma (TNAC study) is ongoing. These researches identified a role of ion channels in the persistence of CSCs and suggested that their inhibitors may have potential as a therapeutic agent for digestive cancers.

Differences of clinical features and outcomes between male and female elderly patients in gastric cancer.

Although the average life span differs between males and females, little is known about differences in clinical features and short and long-term outcomes between elderly male and female gastric cancer patients. This study was designed to clarify these issues to identify the possibility for sex-based treatment strategies in elderly gastric cancer patients. This study included 295 consecutive elderly gastric cancer patients (75 years or older) who underwent curative gastrectomy between 1997 and 2016. We defined postoperative complications as Clavien-Dindo classification grade II or higher. Comorbidities were present in 67% of all patients. Males tended to have more comorbidities than females (P = 0.077). Male patients had significantly more upper gastric cancers (P = 0.001), a higher incidence of postoperative complications (P = 0.045), and poorer prognoses than females (P = 0.003). Multivariate analysis revealed that being male was an independent risk factor for postoperative complications (Odds ratio 2.5, P = 0.045) and a poor prognostic factor (Hazard ratio 1.81, P = 0.008). Patients who underwent limited surgery without postoperative complications tended to have a better prognosis than patients receiving standard surgery with postoperative complications (3-year overall survival: 78% vs. 55%, P = 0.156). Male was an independent risk factor for postoperative complications and an independent poor prognostic factor in elderly gastric cancer patients. To avoid postoperative complications, the limited surgery might be justified for high-risk elderly male patients.

Cancer Stem Cells of Esophageal Adenocarcinoma are Suppressed by Inhibitors of TRPV2 and SLC12A2.

BACKGROUND: The potential of membrane transporters activated in cancer stem cells (CSCs) as new therapeutic targets for cancer is attracting increasing interest. Therefore, the present study examined the expression profiles of ion transport-related molecules in the CSCs of esophageal adenocarcinoma (EAC). METHODS: Cells that highly expressed aldehyde dehydrogenase 1 family member A1 (ALDH1A1) were separated from OE33 cells, a human Barrett's EAC cell line, by fluorescence-activated cell sorting. CSCs were identified based on the formation of tumorspheres. Gene expression profiles in CSCs were examined by a microarray analysis. RESULTS: Among OE33 cells, ALDH1A1 messenger RNA levels were higher in CSCs than in non-CSCs. Furthermore, CSCs exhibited resistance to cisplatin and had the capacity to redifferentiate. The results of the microarray analysis of CSCs showed the up-regulated expression of several genes related to ion channels/transporters, such as transient receptor potential vanilloid 2 (TRPV2) and solute carrier family 12 member 2 (SLC12A2). The cytotoxicities of the TRPV2 inhibitor tranilast and the SLC12A2 inhibitor furosemide were higher at lower concentrations in CSCs than in non-CSCs, and both markedly reduced the number of tumorspheres. The cell population among OE33 cells that highly expressed ALDH1A1 also was significantly decreased by these inhibitors. CONCLUSIONS: Based on the present results, TRPV2 and SLC12A2 are involved in the maintenance of CSCs, and their specific inhibitors, tranilast and furosemide, respectively, have potential as targeted therapeutic agents for EAC.

Effects of TRPV2 on the Expression of PD-L1 and Its Binding Ability to PD-1 in Gastric Cancer.

BACKGROUND: Transient receptor potential vanilloid 2 (TRPV2) is a member of the TRP superfamily of non-specific cation channels with functionally diverse roles. We herein investigated the effects of TRPV2 on the expression of programmed cell death-ligand 1 (PD-L1) and its binding ability to programmed cell death-1 (PD-1) in gastric cancer (GC). METHODS: Knockdown (KD) experiments were performed on human GC cell lines using TRPV2 small-interfering RNA. The surface expression of PD-L1 and its binding ability to PD-1 were analyzed by flow cytometry. Eighty primary tissue samples were assessed by immunohistochemistry (IHC), and the relationships between IHC results, clinicopathological factors, and patient prognosis were analyzed. The molecular mechanisms underlying the effects of TRPV2 on the intracellular ion environment were also investigated. RESULTS: TRPV2-KD decreased the expression level of PD-L1 in NUGC4 and MKN7 cells, thereby inhibiting its binding to PD-1. A survival analysis revealed that 5-year overall survival rates were significantly lower in the TRPV2 high expression and PD-L1-positive groups. In IHC multivariate analysis of GC patients, high TRPV2 expression was identified as an independent prognostic factor. Furthermore, a positive correlation was observed between the expression of TRPV2 and PD-L1. An immunofluorescence analysis showed that TRPV2-KD decreased the intracellular concentration of calcium ([Ca2+]i). Treatment with ionomycin/PMA (phorbol 12-myristate 13-acetate), which increased [Ca2+]i, upregulated the protein expression of PD-L1 and promoted its binding to PD-1. CONCLUSIONS: The surface expression of PD-L1 and its binding ability to PD-1 in GC were regulated by TRPV2 through [Ca2+]i, indicating the potential of TRPV2 as a biomarker and target of immune checkpoint blockage for GC.