Gastroenterological surgery in Japan: The past, the present and the future

Long-Term Outcomes of Pylorus-Preserving Gastrectomy for Early Gastric Cancer

BACKGROUND

In the short term, pylorus-preserving gastrectomy (PPG) has been reported to have advantages over distal gastrectomy (DG) with regard to postprandial symptoms and dumping syndrome. We aimed to evaluate the quality of life after PPG for early gastric cancer in the long term in comparison to that after DG.

METHODS

Twenty-six patients who underwent gastrectomy (11 PPG, 15 DG) for early gastric cancer at Osaka University Hospital participated and were followed for more than 4 years. Body weight changes, nutritional status, dual-phase scintigraphy findings, endoscopic survey results, and questionnaire responses after gastrectomy were examined.

RESULTS

There were significantly lower ratios of weight changes in PPG than in DG, 5 years after surgery. There were no differences in the clinicopathological characteristics, nutritional parameters, questionnaire responses, and endoscopic findings between the two groups. Based on gastric scintigraphy, although the gastric emptying of liquids showed similar curves in the two groups, gastric emptying of solids was significantly slower in the PPG group than in the DG group (P = .039).

DISCUSSION

PPG had advantages with regard to long-term outcomes over DG in terms of weight maintenance and the prevention of rapid gastric emptying. PPG might be efficient in patients with early gastric cancer.

Preoperative Hemoglobin Level as Predictor of the Development of High-output Stoma in Rectal Cancer Surgery

Background/Aim

High-output stomas (HOSs) are a complication that can cause dehydration or renal dysfunction and affect the quality of life of patients, causing water, sodium, and magnesium depletion with malnutrition. Preoperative factors that are useful for predicting HOS are not well defined.

Patients and Methods

A total of nine patients developed HOS among 31 patients who underwent rectal cancer surgery with ileostomies during 2014-2021. Clinicopathological and surgical parameters were also analyzed. HOS was defined as maximum output of ≥2,000 ml/day.

Results

The clinicopathological features did not differ between the HOS and non-HOS groups. Lower Hemoglobin (Hb) levels (<12 mg/dl) and longer operation times (≥300 min) were shown to be risk factors in the development of HOS.

Conclusion

Low Hb levels on preoperative blood tests were predictors of HOS development in patients who underwent rectal cancer surgery and ileostomies simultaneously in our data set. Further studies are required to improve the robustness of these findings.

Omentectomy vs omentum preservation for advanced gastric cancer: A systematic review and meta-analysis

Currently, gastric cancer is the sixth most prevalent cancer in the world. The recommended treatment for advanced disease is gastrectomy with D2 lymphadenectomy. However, there is no consensus regarding the performance of an omentectomy as part of the treatment. The procedure is considered by some authors to be essential for the elimination of a micrometastasis since cells in the peritoneum prefer growing in milky spots in the omentum. On the other hand, retrospective studies demonstrated that there is the possibility that omentum preservation may not impact patients' overall survival. Therefore, the objective of this review was to quantify the effect of performing an omentectomy to determine whether it is necessary. Medline (PubMed), Embase, Cochrane, ClinicalTrials.gov and LILACS were searched up to September 2022. Selection was restricted to comparative studies in patients with advanced GC (≥T2). The certainty of evidence was assessed with GRADEPro and the risk of bias with ROBINS-I and RoB 2.0. Five cohort studies, and one randomized controlled trial (RCT) were included. The meta-analysis found that there were no significant differences between the procedures for overall survival, relapse-free survival, and peritoneal recurrence. Furthermore, in perioperative outcomes, a significant difference was only found in intraoperative bleeding, which was lower in patients who had their omentum preserved. Therefore, omentum preservation in patients with advanced gastric cancer has been shown to have no inferior results than resection in long-term outcomes.

Rubicon can predict prognosis in patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy

BACKGROUND

Despite previous therapeutic studies on autophagy in cancer, its role in the treatment of pancreatic ductal adenocarcinoma remains controversial, especially regarding its effect on chemotherapy, radiotherapy, and both combined. We focused on RUN domain Beclin-1 interacting and cysteine-rich-containing protein (Rubicon) to reveal its contribution to pancreatic ductal adenocarcinoma after chemoradiotherapy.

METHODS

To evaluate the clinical significance of Rubicon, immunohistochemistry was performed, and Rubicon expression was analyzed across 81 specimens resected from patients with pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. A gemcitabine-resistant pancreatic ductal adenocarcinoma cell line was established followed by Rubicon expression and autophagy flux estimation. Finally, gemcitabine sensitivity, invasion ability, and cell viability were evaluated using Rubicon-targeting small interfering RNA.

RESULTS

Rubicon expression in resected pancreatic ductal adenocarcinoma samples after chemoradiotherapy revealed significantly worse overall survival and recurrence-free survival in the Rubicon-high expression group than in the Rubicon-low expression group (overall survival: median [years] 2.02 vs. 3.21, p = 0.0359; recurrence-free survival: median [years] 0.90 vs. 1.90, p = 0.0146). In vitro, gemcitabine-resistant pancreatic ductal adenocarcinoma cell lines exhibited higher Rubicon expression and lower autophagy flux than the parental cell line (p < 0.01). Transduction with small interfering RNA downregulated the expression without affecting gemcitabine sensitivity, but it reduced invasion ability and cell viability (p < 0.01) in the gemcitabine-resistant pancreatic ductal adenocarcinoma cell line.

CONCLUSIONS

High Rubicon expression is a significant, unfavorable prognostic factor in pancreatic ductal adenocarcinoma after neoadjuvant chemoradiotherapy. Downregulation of Rubicon expression improves invasion ability and cell viability in gemcitabine-resistant pancreatic ductal adenocarcinoma.

A novel DNA damage repair gene-related prognostic model for evaluating the prognosis and tumor microenvironment infiltration of esophageal squamous cell carcinoma

BACKGROUND

This study aimed to investigate the potential prognostic value of DNA damage repair genes (DDRGs) in esophageal squamous cell carcinoma (ESCC) and their relationship with immune-related characteristics.

METHODS

We analyzed DDRGs of the Gene Expression Omnibus database (GSE53625). Subsequently, the GSE53625 cohort was used to construct a prognostic model based on least absolute shrinkage and selection operator regression, and Cox regression analysis was used to construct a nomogram. The immunological analysis algorithms explored the differences between the potential mechanism, tumor immune activity, and immunosuppressive genes in the high- and low-risk groups. Of the prognosis model-related DDRGs, we selected PPP2R2A for further investigation. Functional experiments were conducted to evaluate the effect on ESCC cells in vitro.

RESULTS

A 5-DDRG (ERCC5, POLK, PPP2R2A, TNP1 and ZNF350) prediction signature was established for ESCC, stratifying patients into two risk groups. Multivariate Cox regression analysis showed that the 5-DDRG signature was an independent predictor of overall survival. Immune cells such as CD4 T cells and monocytes displayed lower infiltration levels in the high-risk group. Additionally, the immune, ESTIMATE, and stromal scores in the high-risk group were all considerably higher than those in the low-risk group. Functionally, knockdown of PPP2R2A significantly suppressed cell proliferation, migration and invasion in two ESCC cell lines (ECA109 and TE1).

CONCLUSION

The clustered subtypes and prognostic model of DDRGs could effectively predict the prognosis and immune activity of ESCC patients.

Simple Detection and Culture of Circulating Tumor Cells from Colorectal Cancer Patients Using Poly(2-Methoxyethyl Acrylate)-Coated Plates

Here we aimed to establish a simple detection method for detecting circulating tumor cells (CTCs) in the blood sample of colorectal cancer (CRC) patients using poly(2-methoxyethyl acrylate) (PMEA)-coated plates. Adhesion test and spike test using CRC cell lines assured efficacy of PMEA coating. A total of 41 patients with pathological stage II-IV CRC were enrolled between January 2018 and September 2022. Blood samples were concentrated by centrifugation by the OncoQuick tube, and then incubated overnight on PMEA-coated chamber slides. The next day, cell culture and immunocytochemistry with anti-EpCAM antibody were performed. Adhesion tests revealed good attachment of CRCs to PMEA-coated plates. Spike tests indicated that ~75% of CRCs from a 10-mL blood sample were recovered on the slides. By cytological examination, CTCs were identified in 18/41 CRC cases (43.9%). In cell cultures, spheroid-like structures or tumor-cell clusters were found in 18/33 tested cases (54.5%). Overall, CTCs and/or growing circulating tumor cells were found in 23/41 CRC cases (56.0%). History of chemotherapy or radiation was significantly negatively correlated with CTC detection (p = 0.02). In summary, we successfully captured CTCs from CRC patients using the unique biomaterial PMEA. Cultured tumor cells will provide important and timely information regarding the molecular basis of CTCs.

Preoperative diagnosis of tumor depth in gastric cancer using transabdominal ultrasonography compared to using endoscopy and computed tomography

BACKGROUND

An accurate evaluation method for preoperative diagnosis has not yet been established in patients with gastric cancer (GC), though it is essential for optimal treatment. Current standard modalities are endoscopy and contrast computed tomography (CT). In this study, we investigated the efficacy and limitations of transabdominal ultrasonography (TUS) for the assessment of tumor invasion.

METHODS

We enrolled 178 consecutive patients with GC evaluated by TUS, endoscopy, and contrast CT before gastrectomy. For the TUS examination, patients ingested water to fill their stomachs. The clinical staging determined using these modalities was compared to the pathological staging.

RESULTS

The overall accuracy of clinical T staging using TUS was 47.8% (pT1a: 5.8% (2/35); pT1b: 58.8% (20/35); pT2: 69.6% (16/23); pT3: 66.7% (22/33); pT4a: 46% (23/50); pT4b: 100% (2/2)). Using endoscopy, contrast CT, and TUS, the overall accuracy was 60.7%. The accuracy of TUS was associated with the tumor region (U region: 50% (14/28); M: 31.8% (14/44); L: 53.7% (57/106); P = 0.048), but not with the cross-sectional parts (P = 0.49). Multivariate analysis identified inaccurate TUS as independently correlating with tumor region (M vs. U/L, odds ratio (OR) = 3.11, 95% confidence interval (CI) 1.41-6.87; P = 0.005) and pT (pT1 vs. pT2-4, OR = 3.00, 95%CI 1.31-6.87; P = 0.009).

CONCLUSIONS

The present study demonstrated the importance of TUS in evaluating GC. Thus, TUS may be useful for clinical T staging in certain circumstances, leading to treatment optimization.

The functions and molecular mechanisms of Tribbles homolog 3 (TRIB3) implicated in the pathophysiology of cancer

Currently, cancer ranks as the second leading cause of death worldwide, and at the same time, the burden of cancer continues to increase. The underlying molecular pathways involved in the initiation and development of cancer are the subject of considerable research worldwide. Further understanding of these pathways may lead to new cancer treatments. Growing data suggest that Tribble's homolog 3 (TRIB3) is essential in oncogenesis in many types of cancer. The mammalian tribbles family's proteins regulate various cellular and physiological functions, such as the cell cycle, stress response, signal transduction, propagation, development, differentiation, immunity, inflammatory processes, and metabolism. To exert their activities, Tribbles proteins must alter key signaling pathways, including the mitogen-activated protein kinase (MAPK) and phosphatidylinositol 3 kinase (PI3K)/AKT pathways. Recent evidence supports that TRIB3 dysregulation has been linked to various diseases, including tumor development and chemoresistance. It has been speculated that TRIB3 may either promote or inhibit the onset and development of cancer. However, it is still unclear how TRIB3 performs this dual function in cancer. In this review, we present and discuss the most recent data on the role of TRIB3 in cancer pathophysiology and chemoresistance. Furthermore, we describe in detail the molecular mechanism TRIB3 regulates in cancer.

Long noncoding RNA 01534 maintains cancer stemness by downregulating endoplasmic reticulum stress response in colorectal cancer

Background

Studies have shown that cancer stemness and the endoplasmic reticulum (ER) stress response are inversely regulated in colorectal cancer (CRC), but the mechanism has not been fully clarified. Long noncoding RNAs (lncRNAs) play key roles in cancer progression and metastasis. In this study we investigated lncRNA 01534 (LINC01534) as a possible modulator between cancer stemness and ER stress response.

Methods

In vitro experiments using CRC cell lines were performed to explore a possible role of LINC01534. The expression of LINC01534 in clinical CRC samples was assessed by quantitative reverse transcription-polymerase chain reaction (qRT-PCR) and in situ hybridization.

Results

Silencing LINC01534 led to suppression of cell proliferation, invasiveness, and cell cycle progression at the G2-M phase, and promoted apoptosis. Moreover, we found that silencing LINC01534 suppressed cancer stemness, while it activated the ER stress response, especially through the PERK/eIF2α signaling pathway. In situ hybridization revealed LINC01534 was expressed in tumor cells and upregulated in CRC tissues compared with normal epithelium. A survival survey indicated that high LINC01534 expression was significantly associated with shorter overall survival in 187 CRC patients.

Conclusion

This is the first report on LINC01534 in human cancer. Our findings suggest that LINC01534 may be an important modulator of the maintenance of cancer stemness and suppression of the ER stress response, and that it could be a novel prognostic factor in CRC.

The usefulness of presepsin in the diagnosis of postoperative infectious complications after gastrectomy for gastric cancer: a prospective cohort study

This prospective study aimed to evaluate presepsin use as a biomarker of on postoperative infectious complications after gastrectomy, compared to C-reactive protein (CRP), white blood cells (WBCs), and neutrophils (Neuts). Overall, 108 patients were enrolled between October 2019 and December 2020. Presepsin, CRP, WBC, and Neut levels were measured preoperatively and on postoperative days (PODs) 1, 3, 5, and 7, using a postoperative morbidity survey. Grade II or higher infectious complications occurred in 18 patients (16.6%). Presepsin levels on all evaluated PODs were significantly higher in the infectious complication group than in the non-complication group (p = 0.002, p < 0.0001, p < 0.0001, and p = 0.025, respectively). The area under the curve (AUC) values were the highest for presepsin on PODs 3 and 7 (0.89 and 0.77, respectively) and similar to that of CRP, with a high value > 0.8 (0.86) on POD 5. For presepsin, the optimal cut-off values were 298 pg/mL (sensitivity, 83.3%; specificity, 83.3%), 278 pg/mL (sensitivity, 83.3%; specificity, 82.2%), and 300 pg/mL (sensitivity, 83.3%; specificity, 82%) on PODs 3, 5, and 7, respectively. Presepsin levels on PODs 3, 5, and 7 after gastrectomy is a more useful biomarker of postoperative infectious complications compared to CRP, WBCs, and Neuts, with a high sensitivity and specificity.

Clinical outcomes of neoadjuvant chemotherapy for resectable colorectal liver metastasis with intermediate risk of postoperative recurrence: A multi‐institutional retrospective study

Aims

Risk-scoring systems for colorectal liver metastasis (CRLM) after hepatectomy allow prognoses to be predicted preoperatively. We investigated the clinical outcomes of neoadjuvant chemotherapy for resectable CRLM according to patient risk status, aiming to determine the subgroup of patients who could benefit from neoadjuvant chemotherapy.

Methods

In this multi-institutional retrospective analysis, the preoperative risk score was calculated from six previously reported factors: synchronous metastases, primary lymph node positivity, tumor number, largest tumor diameter, extrahepatic metastasis, and the preoperative carbohydrate antigen 19-9 level. Patients were divided into three groups according to their risk scores: low risk (score = 0), intermediate risk (score 1-10), and high risk (score ≥11). Overall and recurrence-free survival curves were calculated using the Kaplan-Meier method. After propensity-score matching in the intermediate-risk group, we compared clinicopathological features and outcomes.

Results

There were 318 cases, from 20 institutions. The preoperative risk score could be calculated in 277 cases. There were 34, 192, and 51 patients in the low-, intermediate-, and high-risk groups, respectively. Intermediate-risk group patients who received neoadjuvant chemotherapy had significantly better recurrence-free survival than that of patients without neoadjuvant chemotherapy (P = .0453). After propensity-score matching in the intermediate-risk group, the recurrence-free survival rate was better in patients who received neoadjuvant chemotherapy (P = .0261). But the overall survival rate was not improved after the matching.

Conclusion

Neoadjuvant chemotherapy for resectable CRLM might prolong the recurrence-free survival period for intermediate-risk patients with preoperative risk scores in the range of 1-10, but the overall survival was not improved by neoadjuvant chemotherapy.

Clinicopathological significance of MYL9 expression in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma is one of the most aggressive malignancies, and often involves invasion and distant metastasis from the early tumor stages. Myosin II reportedly plays a key role in regulating tumor progression and metastasis.

AIMS

We examined whether myosin regulatory light polypeptide 9 (MYL9) regulates cancer cell proliferation.

METHODS AND RESULTS

To investigate the expression pattern and clinical significance of MYL9 in pancreatic ductal adenocarcinoma, we performed immunohistochemical analysis of samples collected from 101 patients with pancreatic ductal adenocarcinoma. The expression of MYL9 was investigated to evaluate its functional role and contribution to proliferation and apoptosis in pancreatic ductal adenocarcinoma cells in vitro. The results showed that MYL9 was predominantly expressed in the cytoplasm and membrane of pancreatic ductal adenocarcinoma cells. Multivariate analysis indicated that MYL9 acted as an independent prognostic factor for overall survival and distant metastasis-free survival. MYL9 expression was strongly associated with malignancy in in vitro analyses, including proliferation and anti-apoptotic activities.

CONCLUSIONS

Our findings suggest that MYL9 is an independent prognostic factor of pancreatic ductal adenocarcinoma. MYL9 is a crucial biomarker and potential therapeutic target for pancreatic ductal adenocarcinoma.

microRNA-497-mediated Smurf2/YY1/HIF2α axis in tumor growth and metastasis of esophageal squamous cell carcinoma

Aberrant expression of microRNA-497 (miR-497) is associated with tumor progression, but the molecular mechanisms in tumorigenesis remain largely unknown. Here, we report that miR-497 expression is downregulated in esophageal squamous cell carcinoma (ESCC) clinical samples. Consistently, upregulation of miR-497 inhibits ESCC cell malignant properties and tumor growth in vivo. Importantly, we uncovered that miR-497 upregulation suppressed ESCC cell growth and tumor growth by inhibiting Smurf2. Mechanistically, we showed that Smurf2 was a target of miR-497, and mediated YY1 expression to elevate HIF2α expression, thereby enhancing the malignancy of ESCC cells. Together, our study uncovered the role of the miR-497-mediated Smurf2/YY1/HIF2α axis in tumor growth and metastasis, which might provide potential therapeutic targets for human ESCC.

Clinical Significance of Acylphosphatase 1 Expression in Combined HCC-iCCA, HCC, and iCCA

BACKGROUND

Combined hepatocellular and cholangiocarcinoma is a rare primary liver cancer with histological features of both hepatocellular carcinoma and intrahepatic cholangiocarcinoma. Little is known about the prognostic features and molecular mechanism of cHCC-iCCA. Acylphosphatase 1 is a cytosolic enzyme that produces acetic acid from acetyl phosphate and plays an important role in cancer progression.

AIMS

We evaluated the clinical significance of ACYP1 expression in cHCC-iCCA, HCC, and iCCA.

METHODS

ACYP1 immunohistochemistry was performed in 39 cases diagnosed with cHCC-iCCA. The prognosis was evaluated in three different cohorts (cHCC-iCCA, HCC, and iCCA). The relationships between ACYP1 expression and cell viability, migration, invasiveness, and apoptosis were examined using siRNA methods in vitro. In vivo subcutaneous tumor volumes and cell apoptosis were evaluated after downregulation of ACYP1 expression.

RESULTS

Almost half of the patients with cHCC-iCCA were diagnosed with high ACYP1 expression. In all three cohorts, the cases with high ACYP1 expression had significantly lower overall survival, and high ACYP1 expression was identified as an independent prognostic factor. Downregulation of ACYP1 reduced the proliferative capacity, migration, and invasiveness of both HCC and iCCA cells. Moreover, knockdown of ACYP1 increased the ratio of apoptotic cells and decreased the expression of anti-apoptosis proteins. In vivo tumor growth was significantly inhibited by the transfection of ACYP1 siRNA, and the number of apoptotic cells increased.

CONCLUSION

High ACYP1 expression could influence the prognosis of cHCC-iCCA, HCC, and iCCA patients. In vitro ACYP1 expression influences the tumor growth and cell viability in both HCC and iCCA by regulating anti-apoptosis proteins.

Multicenter randomised trial of two versus three courses of preoperative cisplatin and fluorouracil plus docetaxel for locally advanced oesophageal squamous cell carcinoma

BACKGROUND

The optimal number of neoadjuvant chemotherapy (NAC) cycles remains to be established for treating oesophageal squamous cell carcinoma (ESCC). We compared two versus three courses of NAC for treating locally advanced ESCC in a multi-institutional, randomised, Phase II trial.

METHODS

We randomly assigned 180 patients with locally advanced ESCC at 6 institutions to either two (N = 91) or three (N = 89) courses of DCF (docetaxel 70 mg/m², cisplatin 70 mg/m² i.v. on day 1, fluorouracil 700 mg/m² continuous infusion for 5 days) every 3 weeks, prior to surgery. The primary endpoint was 2-year progression-free survival (PFS) with an intention-to-treat analysis.

RESULTS

Patient background parameters were well-balanced. The R0 resection rates were 98.9 and 96.5% in the two- and three-course groups, respectively (P = 0.830). In resected cases, the two- and three-course groups had comparable pN0 rates (P = 0.225) and histological responses (P = 0.898). The 2-year PFS rate was also comparable between the two groups (71.4 vs. 71.1%, P = 0.669). Among subgroups based on baseline characteristics, only patients aged under 65 years old showed a tendency for better survival with the three-course treatment (hazard ratio = 2.612, 95% confidence interval: 1.012-7.517).

CONCLUSIONS

Two courses of a DCF regimen showed potential as an optional NAC treatment for locally advanced ESCC.

CLINICAL TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry of Japan (identification number UMIN 000015788).

Association Between Advanced T Stage and Thick Rectus Abdominis Muscle and Outlet Obstruction and High-Output Stoma After Ileostomy in Patients With Rectal Cancer

Objective

This study aimed to identify factors associated with outlet obstruction and high-output stoma (HOS) after ileostomy creation.

Summary of background data

Ileostomy creation is effective in preventing leakage among patients undergoing low anterior resection for rectal cancer. However, major complications such as outlet obstruction and HOS can occur after surgery. Moreover, these complications cannot be prevented.

Methods

This retrospective study included 34 patients with rectal cancer who underwent low anterior resection and ileostomy creation at Okayama University Hospital from January 2015 to December 2018. Then, the risk factors associated with outlet obstruction and HOS were analyzed.

Results

Of 34 patients, 7 (21%) experienced outlet obstruction. In a multivariate logistic regression analysis, advanced T stage (P = 0.10), ileostomy with a short horizontal diameter (P = 0.01), and thick rectus abdominis (RA) muscle (P = 0.0005) were considered independent risk factors for outlet obstruction. There was a significant correlation between outlet obstruction and HOS (P = 0.03). Meanwhile, the independent risk factors of HOS were advanced T stage (P = 0.03) and thick RA muscle (P = 0.04).

Conclusions

Thick RA muscle and advanced T stage were the common risk factors of outlet obstruction and HOS. Therefore, in high-risk patients, these complications can be prevented by choosing an appropriate ileostomy location according to RA muscle thickness and by preventing tubing into the ileostomy.

ACAT-1-Regulated Cholesteryl Ester Accumulation Modulates Gemcitabine Resistance in Biliary Tract Cancer

BACKGROUND

Biliary tract cancer (BTC) has few choices of chemotherapy, including gemcitabine, therefore exploring the mechanisms of gemcitabine resistance is important. We focused on lipid metabolism because biliary tract epithelial cells are essential in cholesterol and bile acid metabolism and the messenger RNA (mRNA) microarray analysis showed high acyl coenzyme A: cholesterol acyltransferase 1 (ACAT-1) expression in BTC gemcitabine-resistant (GR) cell lines. We hypothesized that aberrant accumulation of cholesteryl ester (CE) regulated by ACAT-1 could modulate GR in BTC.

METHODS

CE accumulations were measured in human BTC cell lines, and the relationships between CE levels, ACAT-1 expressions, and gemcitabine sensitivity were analyzed. We performed a small-interfering RNA (siRNA)-mediated knockdown and biochemical inhibition of ACAT-1 in BTC cell lines and alterations of gemcitabine sensitivity were evaluated. To evaluate the clinical significance of ACAT-1 in regard to GR, immunohistochemistry was performed and ACAT-1 expressions were analyzed in resected BTC specimens.

RESULTS

CE levels were correlated with ACAT-1 expressions and GR in four human BTC cell lines. siRNA-mediated knockdown of ACAT-1 in two independent GR cell clones as well as ACAT-1 inhibitor treatment significantly increased gemcitabine sensitivity; knockdown of ACAT-1: 5.63- and 8.02-fold; ACAT-1 inhibitor: 8.75- and 9.13-fold, respectively. ACAT-1 expression in resected BTC specimens revealed that the disease-free survival of the ACAT-1 low-intensity group (median 2.3 years) had a significantly better outcome than that of the ACAT-1 high-intensity group (median 1.1 years) under gemcitabine treatment after surgery (*p < 0.05).

CONCLUSIONS

Our findings suggest that CE and ACAT-1 might be a novel therapeutic target for GR in BTC.

APR-246 induces apoptosis and enhances chemo-sensitivity via activation of ROS and TAp73-Noxa signal in oesophageal squamous cell cancer with TP53 missense mutation

BACKGROUND

Mutations in p53, identified in 90% of oesophageal squamous cell carcinoma (ESCC), are associated with unfavourable prognosis and chemo-resistance. APR-246 induces apoptosis by restoring transcriptional ability of mutant p53, and may be a promising therapeutic agent to overcome chemo-resistance in ESCC.

METHODS

In ESCC cell lines differing in p53 status, we performed in vitro cell viability and apoptosis assays, evaluated reactive oxygen species (ROS) generation, and assessed signal changes by western blot after APR-246 administration with/without chemo-agent. Antitumour effects and signal changes were evaluated in in vivo experiments using xenograft and patient-derived xenograft (PDX) mouse models.

RESULTS

APR-246 administration induced significant apoptosis by upregulating p73 and Noxa via ROS induction in ESCC cell lines harbouring p53 missense mutations. Moreover, APR-246 plus chemotherapy exerted combined antitumour effects in ESCC with p53 missense mutations. This effect was also mediated through enhanced ROS activity, leading to massive apoptosis via upregulation of p73 and Noxa. These findings were confirmed by xenograft and PDX models with p53 mutant ESCC.

CONCLUSION

APR-246 strongly induced apoptosis by inducing ROS activity and p73-Noxa signalling, specifically in ESCC with p53 missense mutation. This antitumour effect was further enhanced by combination with 5-FU, which we first confirmed in ESCC preclinical model.

Two versus three courses of preoperative cisplatin and fluorouracil plus docetaxel for treating locally advanced esophageal cancer: short-term outcomes of a multicenter randomized phase II trial

OBJECTIVE

To compare short-term outcomes between two- vs. three courses of neoadjuvant chemotherapy (NAC) to clarify the optimal treatment for esophageal squamous cell cancer (ESCC) in a multicenter, randomized, phase II trial.

BACKGROUND

An optimal number of NAC cycles remains to be established for locally advanced ESCC.

METHODS

Patients with locally advanced ESCC were randomly assigned to either two (N = 91) or three (N = 89) courses of DCF (70 mg/m² intravenous docetaxel and 70 mg/m² intravenous cisplatin on day 1, and a continuous 700 mg/m² fluorouracil infusion for 5 days) every 3 weeks followed by surgery. We compared the two groups for perioperative parameters, adverse events, and the response to NAC.

RESULTS

The two- and three-course groups showed similar completion rates and overall NAC dose reductions. Although the two-course group showed significantly lower overall grades 3-4 leukopenia and anemia compared to the three-course group, the two groups had similar overall toxicity rates. Postoperative complications were not significantly different between the two groups, except arrhythmia (13 vs. 0%, P = 0.0007). Only two postoperative in-hospital deaths occurred in the three-course group, due to sepsis following severe pneumonia. Compared to the two-course group, the three-course group was associated with a significantly better clinical response (42.9 vs. 65.2%, P = 0.0027) and a relatively higher rate of pathological complete response (9.1 vs. 15.3%, P = 0.212).

CONCLUSION

Both two- and three-course DCF regimens in the NAC setting seemed to be equally feasible in locally advanced ESCC patients. Additional DCF courses led to a better NAC response without increasing the incidence of adverse events or postoperative morbidity.

CLINICAL TRIAL REGISTRATION

University Hospital Medical Information Network Clinical Trials Registry of Japan (Identification Number UMIN 000015788).

Pancreas-left gastric artery angle is associated with postoperative inflammation and drain amylase after laparoscopic gastrectomy

INTRODUCTION

The pancreas often interferes with the surgical field during laparoscopic gastrectomy (LG) and its disorders cause severe postoperative complications. This study aimed to evaluate the association between the anatomical location of the pancreas and surgical outcome and to investigate the optimal surgical position in LG.

METHODS

We newly defined the angle formed between the supra-pancreatic region and the root of the left gastric artery (LGA) as the pancreas-LGA angle (PLA). The association between PLA and surgical outcomes in 107 consecutive patients who underwent laparoscopic distal gastrectomy (LDG) was investigated. Then, the change in PLA before and after insertion of the back pillow in 30 patients with gastric cancer was examined.

RESULTS

The median PLA was 62° (range, 2°-157°). No differences were found in the patient background between patients with small PLA (PLA < 62°; n = 53) and those with large PLA (PLA ≧ 62°; n = 54). The postoperative inflammation response (white blood cells, neutrophils, and C-reactive protein) and amylase concentration in the drainage fluid (D-AMY) were significantly higher in the small PLA group than large PLA group. Multivariable analyses demonstrated that small PLA was an independent risk factor for high D-AMY. After insertion of a back pillow, PLA was noninvasively increased in all patients, and the median PLA was changed to 92° (range, 8°-151°) from 61° (range, 2°-140°). Of 17 patients with small PLA, nine developed large PLA.

CONCLUSIONS

These results suggest that PLA can become one of the indicators of postoperative complications related to anatomical patient factors in LDG.

Preoperative FDG-Positive Lymph Nodes Predict the Postoperative Prognosis in Resectable Biliary Tract Cancers

BACKGROUND

F-18 fluorodeoxyglucose-positron emission tomography (FDG-PET) has been used to diagnose and stage various cancers. In regard to biliary tract cancer (BTC), due to cholangitis it is difficult to evaluate FDG uptake caused by cancer. We previously showed that FDG-positive lymph nodes (LNs) of resectable BTC had a possibility of predicting postoperative prognosis.

OBJECTIVE

This study aimed to validate the usability of FDG-PET for LNs using another cohort and to investigate in detail the relationship between FDG-positive LNs and the prognosis of BTC.

METHODS

We measured the preoperative maximum standardized uptake value (SUV_max) at each of the 190 surgically dissected LN areas in 67 patients and investigated the prognosis using our previously determined SUV_max cut-off values of ≥ 2.8.

RESULTS

Regarding the prognosis of patients with resectable BTC, a LN SUV_max ≥ 2.8 [PET N (+)] was a poor prognostic factor for recurrence-free survival (RFS) compared with a LN SUV_max < 2.8 [PET N (-)]. It was confirmed that the hazard ratio forest plot [PET N (+)/PET N (-)] for RFS indicated a similar tendency among subcategories. Moreover, we investigated patients with pN0 disease and demonstrated that the PET N (+) group also had a significantly worse RFS outcome compared with the PET N (-) group. Recurrence of the PET N (+) group has significantly occurred more often in LNs than that of the PET N (-) group.

CONCLUSION

High LN SUV_max was confirmed to be the preoperatively diagnosed prognostic risk factor for RFS in resectable BTC and could be helpful for clinical decision making regarding the perioperative treatment strategy.

Propranolol suppresses gastric cancer cell growth by regulating proliferation and apoptosis

BACKGROUND

Despite improvements in gastric cancer treatment, the mortality associated with advanced gastric cancer is still high. The activation of β-adrenergic receptors by stress has been shown to accelerate the progression of several cancers. Accordingly, increasing evidence suggests that the blockade of β-adrenergic signaling can inhibit tumor growth. However, the effect of β-blockers, which target several signaling pathways, on gastric cancer remains to be elucidated. This study aimed to investigate the anti-tumor effects of propranolol, a non-selective β-blocker, on gastric cancer.

METHODS

We explored the effect of propranolol on the MKN45 and NUGC3 gastric cancer cell lines. Its efficacy and the mechanism by which it exerts anti-tumor effects were examined using several assays (e.g., cell proliferation, cell cycle, apoptosis, and wound healing) and a xenograft mouse model.

RESULTS

We found that propranolol inhibited tumor growth and induced G1-phase cell cycle arrest and apoptosis in both cell lines. Propranolol also decreased the expression of phosphorylated CREB-ATF and MEK-ERK pathways; suppressed the expression of matrix metalloproteinase-2, 9 and vascular endothelial growth factor; and inhibited gastric cancer cell migration. In the xenograft mouse model, propranolol treatment significantly inhibited tumor growth, and immunohistochemistry revealed that propranolol led to the suppression of proliferation and induction of apoptosis.

CONCLUSIONS

Propranolol inhibits the proliferation of gastric cancer cells by inducing G1-phase cell cycle arrest and apoptosis. These findings indicate that propranolol might have an opportunity as a new drug for gastric cancer.

Lymph Node Response to Neoadjuvant Chemotherapy as an Independent Prognostic Factor in Metastatic Esophageal Cancer

OBJECTIVE

The aim of this study was to evaluate primary tumor (PT) and lymph node (LN) responses to neoadjuvant chemotherapy (NACT) for predicting long-term survival in patients with metastatic esophageal cancer (EC).

BACKGROUND

In evaluating NACT responses in patients with EC, imaging modalities typically target the PT in the esophagus, which is unmeasurable. Targeting measurable organs, like positive LNs, might provide more accurate assessments.

METHODS

We enrolled 251 patients with EC and clinically positive LNs that underwent curative resections, after triplet NACT. The percent reduction of PT area was measured with bidimensional computed tomography. The LN response was defined as the percent reduction of the sum of the short diameters in all positive LNs.

RESULTS

NACT reduced PTs and LNs by (median, range) 58.0% (38.1-94.9) and 34.5% (46.2-68.2), respectively. Based on the receiver-operating characteristic analyses for predicting a histological response and a 10% stepwise cutoff analyses of recurrence-free survival (RFS), responder/nonresponder cutoff values were ≥60% for PT area reductions and ≥30% for LN size reductions. 39.6% of patients showed discordant PT and LN responses. Compared with PT-responders, LN-responders had significantly less advanced pN (P < 0.0001) and pM (P = 0.015) in addition to less advanced pT (P < 0.0001) and better histological responses (P < 0.0001), and closer correlations to lymphatic, distant metastases and dissemination. A multivariate analysis of RFS identified 2 independent prognostic factors: the LN response [hazard ratio (HR) = 2.51, 95% confidence interval (CI) = 1.63-3.95, P < 0.0001] and the pN (HR = 2.72, 95% CI = 1.44-5.64, P = 0.0016), but not the PT response.

CONCLUSIONS

The LN response to NACT predicted long-term survival more precisely than the PT response in patients with metastatic EC.

Inhibition of c-MET reverses radiation-induced malignant potential in pancreatic cancer

As a treatment option for PDAC, radiation therapy induces good local control. However, radiation also reportedly enhances the malignant potential (e.g., invasion and migration ability) in various cancers, thus increasing the risk of distant metastasis. It remains unclear how radiation induces malignant potential, and how such enhanced malignant potential can be suppressed. In the current study, we evaluated the sequential change of c-Met expression in pancreatic cancer cells following irradiation. We found that irradiation transiently induced c-Met expression in vitro. In an in vivo subcutaneous tumor mouse model, irradiation also enhanced downstream phosphorylated Met (p-Met). Furthermore, this enhancement of p-Met protein expression was suppressed by oral administration of the c-Met inhibitor INC280. Irradiated pancreatic cancer cells with enhanced c-Met expression exhibited higher malignant potential, including invasion and migration ability, compared with cells showing low c-Met expression. Pancreatic cancer cells that overexpressed c-met also showed enhanced malignant potential, which was reversed by c-Met inhibition. Additionally, c-Met inhibitor suppressed the metastatic potential in a liver metastasis mouse model using c-met-overexpressing cells. Overall, our present results revealed that irradiation could induce c-met expression in pancreatic cancer cells, leading to enhanced malignant potential (e.g., invasion and migration ability) and thus promoting distant metastasis. Moreover, a c-Met inhibitor could reverse this enhanced malignant potential.

An Update on the Potential Roles of E2F Family Members in Colorectal Cancer

Colorectal cancer (CRC) is a major health burden worldwide, and thus, optimised diagnosis and treatments are imperative. E2F transcription factors (E2Fs) are a family of transcription factors consisting of eight genes, contributing to the oncogenesis and development of CRC. Importantly, E2Fs control not only the cell cycle but also apoptosis, senescence, DNA damage response, and drug resistance by interacting with multiple signaling pathways. However, the specific functions and intricate machinery of these eight E2Fs in human CRC remain unclear in many respects. Evidence on E2Fs and CRC has been scattered on the related regulatory genes, microRNAs (miRNAs), and competing endogenous RNAs (ceRNAs). Accordingly, some drugs targeting E2Fs have been transferred from preclinical to clinical application. Herein, we have systemically reviewed the current literature on the roles of various E2Fs in CRC with the purpose of providing possible clinical implications for patient diagnosis and prognosis and future treatment strategy design, thereby furthering the understanding of the E2Fs.

Modified Cavoportal Hemitransposition for Severe Portal Vein Thrombosis Contributed to Long-term Survival After Deceased Donor Liver Transplantation-Insight Into Portal Modulation for Improving Survival: A Case Report

BACKGROUND

Severe/massive portal vein thrombosis (PVT) deteriorates peri-liver transplantation outcomes. Cavoportal hemitransposition (CPHT) is a rescue procedure for severe PVT, and short-term outcomes have been well studied. However, CPHT is associated with some long-term issues caused by portal flow modulation via extraordinary reconstruction. We describe a patient with Yerdel grade 4 PVT who underwent a liver transplant and achieved long-term survival with CPHT and a portosystemic shunt.

CASE REPORT

A 50-year-old man with liver cirrhosis underwent a deceased donor liver transplant. Preoperative examinations indicated Yerdel grade 4 PVT; thus, we planned a CPHT. In liver transplant surgery, we confirmed diffusely complete PVT and removed them as possible. After placing a liver graft, we performed CPHT and confirmed that the graft received sufficient portal vein flow. However, the gastroepiploic vein pressure increased significantly. Therefore, we added a portosystemic shunt between the splenic vein and the inferior vena cava, and the pressure improved. The patient was discharged after an uneventful hospital stay, and he reported no unfavorable events for over 12 years.

CONCLUSIONS

This case study suggested that a modified CPHT with a portosystemic shunt for Grade 4 PVT was useful in preventing post-liver transplant PVT development and improved the outcome.

Radical lymphadenectomy of a para-aorta lymph node metastasis in colorectal cancer prolongs relapse-free survival

BACKGROUND

It is highly controversial whether a lymphadenectomy for treating distant lymph nodes, such as the para-aortic lymph node, provides clinical benefit in colorectal cancer (CRC). This study aimed to investigate the benefit of a lymphadenectomy for para-aortic lymph node metastasis (PALM) in CRC, by evaluating the extent of dissection.

METHODS

This retrospective cohort study included 28 consecutive patients with pathologically positive PALMs in CRC that underwent lymphadenectomies from October 2001 to March 2018 at our institute. We analyzed the rates of 3-year recurrence-free survival (RFS), postoperative complications, and peri-operative death. We examined RFS in two groups with different operation types. One group received radical resections (radical group), defined as a systematic dissection of para-aortic lymph nodes, which removed the area under the renal vein and above the aortic bifurcation. The other group (targeted group) received targeted dissections, which removed specific swollen para-aortic lymph nodes.

RESULTS

The radical group had a significantly better RFS than the targeted group. In addition, females had significantly better RFS prognoses than males. Univariate and multivariate Cox regression analyses identified two clinical factors significantly associated with RFS: sex (P = 0.0100) and surgical procedure (P = 0.0033). Postoperative complications after PALM resections occurred in 35.7% of patients. There was no postoperative mortality.

CONCLUSION

Our study suggested that a radical lymphadenectomy for treating PALMs in CRC could be performed safely and could prolong the RFS. More studies are necessary to strengthen the evidence in support of this conclusion.

Citation classics: the 50 most cited articles in surgery in Asia

Objective: The term ‘citation classics’ is used for highly cited papers in the scientific literature. It was aimed to understand the current landscape of academic surgery and the quality of the scientific contribution of authors belonging to Asia using citation classics.

Material and Methods: We searched the WoS core collection database under the category ‘surgery’ to include the 50 most cited articles whose lead author was affiliated to an Asian country during the research period. We noted the following characteristics for each article: total citations, average cita- tions per year, year of publication, publishing journal, institution and country, journal quartile and impact factor, authorship, field of surgical research. Results were analyzed using IBM SPSS Statistics v26.

Results: The number of citations ranged from 447 to 1170 (mean +/- SD is 616.9 +/- 150.16) and citations per year ranged from 10.04 to 98.17 (mean +/- SD is 30.87 +/- 17.27). Most productive decade was 1991-2000 (n= 19 articles). Majority of the articles were published in ‘Annals of Surgery’ (28%). Four authors contributed two or more articles as lead author with ‘Poon RTP’ taking the lead. Japan’s contribution was highest (60%) followed by China and its dependents’ (26%). University of Hong Kong was the leading institution (n= 7). Observational study was the most commonly used design (n= 24). Most papers belonged to gastrointestinal surgery (n= 28) and surgical oncology (n= 26). 66% articles originated from a single institution, 22% had inter-institutional collaboration and 12% had national collaboration from countries outside Asia.

Conclusion: The study identified the most influential papers in surgery from Asia. This should provoke interest in academic surgery and research col- laboration with other nations in Asia and the rest of the world.

FMS-Related Tyrosine Kinase 3 Ligand Promotes Radioresistance in Esophageal Squamous Cell Carcinoma

Aim: The FMS-related tyrosine kinase 3 ligand (FL) has an important role in regulating FMS-related tyrosine kinase 3 (Flt-3) activity. Serum FL levels are markedly increased among patients with hematopoietic disease. However, its role in radiation treatment remains unclear. In this study, we investigated the effects of FL on radiotherapy for esophageal squamous cell carcinoma (ESCC).

Methods: KYSE150 and KYSE450 cells were stimulated with FL (200 ng/ml). mRNA expression was analyzed using qRT-PCR. Cell viability was checked using CCK-8 assay kits. Proliferation was determined using the EdU assay. Radiosensitivity was detected through a colony-forming assay. Flow cytometry was used to evaluate cell apoptosis. The number of γH2AX foci was verified using an immunofluorescence assay. The change in relative proteins was determined by western blot analysis. The growth of transplanted tumors was demonstrated in nude mice.

Results: Our results showed that FL increased the radiation resistance of ESCC cells by promoting clone formation, increasing EdU incorporation, enhancing DNA damage repair, and inhibiting apoptosis. Moreover, the Flt-3 receptor expression significantly increased in ESCC cells after radiation, which may have been an important factor in their radioresistance.

Conclusion: Our results suggest that FL increases the radioresistance of esophageal cancer cells and that FL-Flt-3 could be a potential target for enhancing radiosensitivity in ESCC.

Association of Malnutrition, as Defined by the PG-SGA, ESPEN 2015, and GLIM Criteria, With Complications in Esophageal Cancer Patients After Esophagectomy

Background: There are several approaches that can be used for the pre-treatment identification of malnutrition in oncology populations including the Patient-Generated Subjective Global Assessment (PG-SGA), the 2015 consensus statement by the European Society for Clinical Nutrition and Metabolism (ESPEN 2015) and the Global Leadership Initiative on Malnutrition (GLIM).

Aims: This study aimed to evaluate whether malnutrition, as defined by these three methods, can be used to predict complications in esophageal cancer (EC) patients after esophagectomy.

Methods: We performed a single center, observational cohort study that included 360 EC patients undergoing esophagectomy from December 2014 to November 2019 at Daping Hospital in China. The prevalence of malnutrition in the study population was prospectively defined using the PG-SGA (≥9 defined malnutrition), and retrospectively defined using the ESPEN 2015 and the GLIM. The prevalence of malnutrition and association with postoperative complications were compared in parallel for the three methods.

Results: The prevalence of malnutrition before surgery was 23.1% (83/360), 12.2% (44/360), and 33.3% (120/360) in the study population, as determined by the PG-SGA, the ESPEN 2015 and the GLIM, respectively. The PG-SGA and GLIM had higher diagnostic concordance (Kappa = 0.519, P < 0.001) compared to the ESPEN 2015 vs. GLIM (Kappa = 0.361, P < 0.001) and PG-SGA vs. ESPEN 2015 (Kappa = 0.297, P < 0.001). The overall incidence of postoperative complications for the study population was 58.1% (209/360). GLIM- and ESPEN 2015-defined malnutrition were both associated with the total number of postoperative complications in multivariable analyses. Moreover, GLIM-defined malnutrition exhibited the highest power to identify the incidence of complications among all independent predictors in a pooled analysis.

Conclusion: Among the PG-SGA, the ESPEN 2015 and the GLIM, the GLIM framework defines the highest prevalence rate of malnutrition and appears to be the optimal method for predicting postoperative complications in EC patients undergoing esophagectomy. These results support the importance of preoperatively identifying malnutrition using appropriate assessment tools, because it can facilitate the selection of management strategies that will optimize the clinical outcomes of EC patients.

Targeting cancer stem cells in refractory cancer

Although common cancer therapies, such as chemotherapy and radiation therapy, have recently improved and yielded good results, evaluated as tumor shrinkage, disease recurrence is still a common event for most cancer patients. This is termed refractory cancer. This tumor regrowth following therapy is generally thought to be caused by a small, specific population of tumor cells called cancer stem cells (CSCs). Similar to other stem cells, CSCs have the capacity for self-renewal and multipotent differentiation, and they have been identified in many tumor types based on cell surface protein expression. This specific cell population has stemness characteristics as examined by serial transplantation in animal models. Previous studies have developed a specific signature of cell surface markers and biological functions that can identify CSCs in many solid tumors. In this review, we summarize the characterization of CSCs using new techniques for identifying and quantifying them in situ. These techniques and concepts could be valuable for evaluating the effects of therapies on this cell population. Finally, we conclude by discussing several unique preclinical treatment strategies to targets CSCs, such as reprogramming CSCs or inducing attack by immune cells. Therapeutic and diagnostic methodologies that can target and quantify CSCs will be valuable tools for eradicating refractory cancer.

Serum exosomal miR-638 is a prognostic marker of HCC via downregulation of VE-cadherin and ZO-1 of endothelial cells

Hepatocellular carcinoma (HCC) is the second leading cause of cancer‐related death. High recurrence rates after curative resection and the lack of specific biomarkers for intrahepatic metastases are major clinical problems. Recently, exosomal microRNAs (miRNAs) have been reported to have a role in the formation of the pre‐metastatic niche and as promising biomarkers in patients with malignancy. Here we aimed to clarify the molecular mechanisms of intrahepatic metastasis and to identify a novel biomarker miRNA in patients with HCC. A highly intrahepatic metastatic cell line (HuH‐7M) was established by in vivo selection. HuH‐7M showed increased proliferative ability and suppression of apoptosis and anoikis. HuH‐7M and the parental cell (HuH‐7P) showed the similar expression of epithelial‐mesenchymal transition markers and cancer stem cell markers. In vivo, mice treated with exosomes derived from HuH‐7M showed increased tumorigenesis of liver metastases. Exosomes from HuH‐7M downregulated endothelial cell expression of vascular endothelial‐cadherin (VE‐cadherin) and zonula occludens‐1 (ZO‐1) in non‐cancerous regions of liver and increased the permeability of FITC‐dextran through the monolayer of endothelial cells. The miRNAs (miR‐638, miR‐663a, miR‐3648, and miR‐4258) could attenuate endothelial junction integrity by inhibiting VE‐cadherin and ZO‐1 expression. In patients with HCC, higher serum exosomal miR‐638 expression was associated with tumor recurrence. In conclusion, the miRNAs secreted from a highly metastatic cancer cell can promote vascular permeability via downregulation of endothelial expression of VE‐cadherin and ZO‐1. Serum exosomal miR‐638 expression holds potential for serving as a significant and independent prognostic marker in HCC.

SIRT3-Mediated SOD2 and PGC-1α Contribute to Chemoresistance in Colorectal Cancer Cells

BACKGROUND

Anticancer drugs generate excessive reactive oxygen species (ROS), which can cause cell death. Cancer cells can resist this oxidative stress, but the mechanism of resistance and associations with chemoresistance are unclear. Here, we focused on Sirtuin 3 (SIRT3), a deacetylating mitochondrial enzyme, in oxidative stress resistance in colorectal cancer (CRC).

METHODS

To evaluate SIRT3-related changes in mitochondrial function, ROS (mtROS) induction, and apoptosis, we used the human CRC cell lines HT29 and HCT116 transfected with short-hairpin RNA targeting SIRT3 and small interfering RNAs targeting superoxide dismutase 2 mitochondrial (SOD2) and peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α). In 142 clinical specimens from patients with CRC, we also assessed the association of SIRT3 protein levels (high/low) and prognosis.

RESULTS

SIRT3 expression correlated with mtROS generation and apoptosis induction in cells treated with anticancer agents. Suppressing SIRT3 increased mtROS levels and cell sensitivity to anticancer agents. SIRT3 knockdown decreased SOD2 expression and activity, and suppressing SOD2 also improved sensitivity to anticancer drugs. In addition, SIRT3 was recruited with PGC-1α under oxidative stress, and suppressing SIRT3 decreased PGC-1α expression and mitochondrial function. PGC-1α knockdown decreased mitochondrial activity and increased apoptosis in cells treated with anticancer drugs. In resected CRC specimens, high vs low SIRT3 protein levels were associated with significantly reduced cancer-specific survival.

CONCLUSIONS

SIRT3 expression affected CRC cell chemoresistance through SOD2 and PGC-1α regulation and was an independent prognostic factor in CRC. SIRT3 may be a novel target for CRC therapies and a predictive marker of sensitivity to chemotherapy.

Reduced Port Surgery for a Pregnant Woman With Strangulated Small Bowel Obstruction: A Case Report

Introduction

Intestinal obstruction in pregnancy is very rare, but the maternal mortality rate and the fetal loss rate are high. Therefore, an early diagnosis and appropriate treatments for small bowel obstructions (SBOs) during pregnancy are crucial for the mothers and fetuses. On the other hand, laparoscopic surgeries are widely used in pregnant patients, although laparoscopic surgeries for SBOs can have higher risks of complications. Then, reduced port surgery (RPS) can reduce the risk of intestinal injury by minimizing the number of ports the operator could not control alone. There is no previous report of RPS for SBOs in pregnant patients. We report on a pregnant patient with a strangulated SBO treated with RPS without complications.

Case presentation

A 37-year-old Japanese pregnant woman complaining of severe abdominal pain was admitted by ambulance. Her gestational age was 9 weeks. Her medical history included surgery for acute perforated appendicitis and deep vein thrombosis due to anti-thrombin III deficiency. Abdominal computed tomography revealed a strangulated SBO. We performed RPS and the cause of strangulated SBO was a string at the postoperative site of the appendectomy. The ischemic region of the small bowel recovered after we cut the string and released the adhesion. The patient's postoperative course was uneventful and the fetus was not harmed.

Conclusion

This is the first report of RPS performed for the pregnant patient with the strangulated SBO. Our findings indicate that RPS is a feasible treatment for strangulated SBOs in pregnant women.

Inhibition of glycolytic activator PFKFB3 suppresses tumor growth and induces tumor vessel normalization in hepatocellular carcinoma

Glycolysis emerges as a new therapeutic target for malignancies. The inhibition of glycolytic activator, PFKFB3, repairs tumor endothelial cell function, and normalizing the tumor microenvironment. We aimed to investigate the significance of PFKFB3 in HCC, and the effects of the PFKFB3 inhibitor, PFK15, in HCC tumor cells and tumor endothelial cells. Double immunofluorescent staining of PFKFB3 and CD31 in HCC tissues revealed that high PFKFB3 expression in both tumor cells and tumor endothelial cells was significantly correlated with poor prognosis. Multivariate analysis identified PFKFB3 expression as an independent prognostic factor. PFK15 suppressed proliferation of HCC cell line and tumor endothelial cells in vitro. In a subcutaneous tumor model of the HCC cell line with tumor endothelial cells, PFK15 suppressed tumor growth and induced apoptosis. Moreover, PFK15 treatment induced tumor vessel normalization, decreasing vessel diameter with pericyte attachment and improving vessel perfusion. High PFKFB3 expression in both tumor cells and tumor endothelial cells was identified as a novel prognostic marker in HCC. Targeting PFKFB3 via PFK15 might be a promising strategy for suppressing tumor growth and inducing tumor vessel normalization.

The blockade of interleukin-33 released by hepatectomy would be a promising treatment option for cholangiocarcinoma

Interleukin-33 (IL-33), an alarmin released during tissue injury, facilitates the development of cholangiocarcinoma (CCA) in a murine model. However, it is unclear whether IL-33 is associated with human CCA. The aim of this study was to support the following hypothesis: IL-33 is released during hepatectomy for CCA, subsequently facilitating the development of subclinical CCA and eventually leading to recurrent disease. IL-33 expression was assessed in various samples from both humans and mice including resected liver and paired plasma samples collected at hepatectomy and after surgery, and its influences on recurrent disease and patient prognosis were determined. Homogenized human liver samples with high or low IL-33 expression were added to the culture medium of human CCA cells, and the changes in proliferation and migration were evaluated. To examine the effects of inhibiting the IL-33 release induced by hepatectomy, syngraft transplantation of murine CCA cells was performed in C57BL/6J mice with or without IL-33 blockade. The amount of IL-33 released into the plasma during hepatectomy correlated with the background liver expression. High expression of IL-33 in the liver was an independent risk factor for recurrence. Homogenized liver tissue strongly expressing IL-33 increased both the proliferation and migration of tumor cells. Mice who underwent hepatectomy exhibited CCA progression in the remnant liver, whereas blockade of IL-33 during hepatectomy inhibited tumor progression. Thus, we concluded that surgery for CCA with curative intent paradoxically induced IL-33 release, which facilitated CCA recurrence, and anti-IL-33 therapy during hepatectomy might reduce the risk of CCA recurrence.

Randomized controlled Phase III trial to evaluate omentum preserving gastrectomy for patients with advanced gastric cancer (JCOG1711, ROAD-GC)

Gastrectomy with omentectomy and D2 lymph node dissection is the current standard procedure for locally advanced gastric cancer. However, some retrospective studies have reported that omentectomy increased post-operative abdominal complications but provided no survival advantage over omentum preservation. Therefore, we plan a randomized controlled phase III trial to confirm the non-inferiority of omentum preservation compared with omentectomy in patients with cT3 (SS) or cT4a (SE) gastric cancer. A total of 1050 patients will be enrolled from 62 institutions over a period of 6.5 years. The primary end point is relapse-free survival, and the secondary end points are overall survival, blood loss, operation time and adverse events. This trial has been registered at the UMIN Clinical Trials Registry as UMIN000036253.

A Four-Dimensional Organoid System to Visualize Cancer Cell Vascular Invasion

Simple Summary

Using vascular organoid culture with collagen microfiber, we have established a method for culturing organoids that recapitulates the vascular invasion process of cancer cells. This culture model made it possible to four-dimensionally evaluate the dynamics of cancer cells infiltrating into blood vessels.

Abstract

Vascular invasion of cancer is a critical step in cancer progression, but no drug has been developed to inhibit vascular invasion. To achieve the eradication of cancer metastasis, elucidation of the mechanism for vascular invasion and the development of innovative treatment methods are required. Here, a simple and reproducible vascular invasion model is established using a vascular organoid culture in a fibrin gel with collagen microfibers. Using this model, it was possible to observe and evaluate the cell dynamics and histological positional relationship of invasive cancer cells in four dimensions. Cancer-derived exosomes promoted the vascular invasion of cancer cells and loosened tight junctions in the vascular endothelium. As a new evaluation method, research using this vascular invasion mimic model will be advanced, and applications to the evaluation of the vascular invasion suppression effect of a drug are expected.

Heterogeneity of Treg/Th17 According to Cancer Progression and Modification in Biliary Tract Cancers via Self-Producing Cytokines

BACKGROUND/AIM

We previously demonstrated that inflammatory cytokine interleukin-6 (IL-6) was produced during cancer progression, worked together with transforming growth factor-beta 1 (TGF-β1), and induced the epithelial-mesenchymal transition (EMT) with chemo-resistance against gemcitabine (GR) at the invasion front of biliary tract cancers (BTCs). However, the significance of cytokine-induced T cell accumulation at the tumor microenvironment in biliary tract cancer (BTC) is not well understood. Because these cytokines (IL-6 and TGF-β1) are able to differentiate naïve T cells into Foxp3-expressing T cells (Tregs) and/or IL-17-producing T helper 17 (Th17) cells, we investigated the relationship between heterogeneous, cancer-producing cytokines and T cell differentiation.

METHODS

In total, 127 curative resected specimens from patients with BTCs at Osaka University Hospital between 2000 and 2012 were evaluated for IL-6, TGF-β1, Tregs, and Th17 cells by immunohistochemistry. The ability of BTC-GR cells to undergo T cell differentiation was investigated in vitro.

RESULTS

Tregs accumulated at the tumor center and Th17 cells accumulated at the invasion front during cancer progression and/or metastasis; each signaled poor prognosis. Treg accumulation was related to TGF-β1 expression by cancer cells, and Th17 cell accumulation was related to IL-6 expression by cancer cells, in resected specimens; this was confirmed in vitro. Compared with parent cells, GR cells produced IL-6 but not TGF-β1 in a time-dependent manner, had EMT features, and induced T cell differentiation to Th17 cells but not Tregs.

CONCLUSION

Cytokines produced by cancer cells (IL-6 and TGF-β1) induced heterogeneity of Tregs and Th17 cells in the tumor microenvironment, supporting progression of BTC.

Invasion category-oriented lymph node metastases of cholangiocarcinoma and the prognostic impact

PURPOSE

It was speculated that intrahepatic cholangiocarcinoma (ICC) invasion would influence cancer progression, such as lymph node (LN) metastasis, and the efficacy of LN dissection (LND). The purpose of this study is to evaluate the LN metastatic pattern of intrahepatic cholangiocarcinoma, including the invasion category and prognosis after surgical resection, in order to explore effective LND.

METHODS

We analyzed a prospectively collected cohort for ICC with a previously reported invasion category: hilar type, showing invasion to the main or first branch of Glisson; peripheral type, showing no invasion to less than the third branch; and intermediate type, for all others.

RESULTS

Data from a total of 180 patients who underwent surgical resection were analyzed (LN dissection in 142 (79%)). In single ICC, hilar type had a higher LN metastatic rate than the others (hilar; 23/45 (51%), intermediate; 7/25 (28%), peripheral; 1/34 (3%)). Although the survival with LN metastasis (LN+) was worse, single and hilar/intermediate ICC LN+ had a better survival than peripheral type LN+ (3-year OS: hilar/intermediate 30-37%, peripheral 0%). The most frequent LN metastatic region was the hepatico-duodenal ligament for all invasion categories, and the LN metastatic region was not related to the survival. In peripheral ICC, LND did not affect the survival. By contrast, hilar/intermediate ICC LN+ had a better survival than did peripheral ICC LN+, and the 3-year OS was ≥ 20%.

CONCLUSION

LN metastasis depended on the ICC invasion category in addition to the tumor number, which affected patients' survival and the need for LND. In hilar-type disease, LN dissection may contribute to the survival.

Adjuvant Chemotherapy after Neoadjuvant Chemotherapy and Long-term Outcomes of CAPOX Plus Bevacizumab Followed by TME for High-risk Localized Rectal Cancer

Objectives:

We previously reported the feasibility of neoadjuvant capecitabine and oxaliplatin plus bevacizumab as a treatment for locally advanced rectal cancer (UMIN000003219). The aim of this study is to investigate the prognostic relevance of neoadjuvant chemotherapy followed by total mesorectal resection (TME).

Methods:

Twenty-five patients of our prior multicenter prospective study of neoadjuvant chemotherapy followed by TME enrolled to this study. We analyzed the adjuvant chemotherapy regimen, and the duration between surgery and initial chemotherapy treatment. Five-year progression-free survival and overall survival were estimated using the Kaplan-Meier method.

Results:

Among survivors, the median follow-up time was 66 months. Recurrence occurred in six patients, all of whom had suboptimal tumor regression after neoadjuvant chemotherapy. Five patients died from other causes. The rate of local recurrence and distant metastasis was 17.4% and 8.7%, respectively. Five-year progression-free survival was 70.0%, and 5 year overall survival was 84.0%.

Conclusions:

We report the long-term survival of patients who received neoadjuvant chemotherapy without radiation followed by TME, revealing a generally favorable prognosis.

Postoperative Long-Term Outcomes in Elderly Patients with Gastric Cancer and Risk Factors for Death from Other Diseases

BACKGROUND

Elderly patients with gastric cancer are frequently treated surgically in current clinical practice. Although several studies have investigated short-term outcomes after gastrectomy in elderly patients, most did not evaluate long-term outcomes.

METHODS

We analyzed 1154 consecutive patients who underwent curative gastrectomy for gastric cancer between 2001 and 2013. We classified them into two groups: the elderly group (n = 241), consisting of patients aged ≥75 years, and the non-elderly group (n = 913), consisting of patients aged <75 years, and compared the short- and long-term outcomes between the two groups. The risk factors for death from other diseases in elderly patients were also examined.

RESULTS

Although the incidence of postoperative pneumonia was significantly higher in the elderly group (P < 0.001), the proportion of overall postoperative complications did not differ significantly between the two groups (P = 0.097). The disease-specific survival was similar between the two groups (P = 0.743), whereas the overall survival in the elderly group was significantly shorter than that in the non-elderly group (P < 0.001) because of a higher incidence of death from other diseases throughout all gastric cancer stages. Multivariate analysis revealed that a low preoperative prognostic nutrition index (PNI) and multiple comorbidities were significant risk factors for death from other diseases within 5 years in the elderly group.

CONCLUSIONS

Despite acceptable short-term outcomes, long-term outcomes in elderly patients with gastric cancer were poor due to the high incidence of death from other diseases. Indications for surgery in elderly patients with a low PNI or multiple comorbidities should be considered carefully.

Syntenin-1 promotes colorectal cancer stem cell expansion and chemoresistance by regulating prostaglandin E2 receptor

Background

The protein syntenin-1 is expressed by a variety of cell types, and is upregulated in various malignancies, including melanoma, breast cancer and glioma. Although the mechanism by which elevated syntenin-1 expression contributes to cancer has been described, the exact pathway has not been elucidated.

Methods

To investigate the involvement of syntenin-1 in colorectal cancer (CRC), we performed immunohistochemical analysis of 139 CRC surgical specimens. We also examined syntenin-1 knockdown in CRC cell lines.

Results

High syntenin-1 expression was associated with less differentiated histologic grade and poor prognosis, and was an independent prognostic indicator in CRC. Syntenin-1 knockdown in CRC cells reduced the presence of cancer stem cells (CSCs), oxaliplatin chemoresistance and migration. DNA microarray analysis and quantitative real-time polymerase chain reaction showed decreased prostaglandin E2 receptor 2 (PTGER2) expression in syntenin-1-knockdown cells. PTGER2 knockdown in CRC cells yielded the same phenotype as syntenin-1 knockdown. Celecoxib, which has anti-inflammatory effects by targeting cyclooxygenase-2, reduced CSCs and decreased chemoresistance, while prostaglandin E2 (PGE2) had the opposite effect.

Conclusions

Our findings suggested that syntenin-1 enhanced CSC expansion, oxaliplatin chemoresistance and migration capability through regulation of PTGER2 expression. Syntenin-1 may be a promising new prognostic factor and target for anti-cancer therapies.

The Pattern of Residual Tumor After Neoadjuvant Chemotherapy for Locally Advanced Esophageal Cancer and Its Clinical Significance

OBJECTIVES

To investigate the residual pattern of esophageal cancer in the esophageal wall after neoadjuvant chemotherapy (NAC) and its clinical significance.

BACKGROUND

NAC is a standard treatment for locally advanced esophageal cancer; however, residual tumor patterns in resected specimens after NAC and their clinico-pathological characteristics remain unknown.

METHODS

One hundred twenty consecutive patients with cT3 or deeper esophageal cancer underwent curative esophagectomy after NAC and achieved grade 2 histological responses between 2000 and 2016. Hematoxylin-eosin staining of residual tumor sections revealed 4 remnant categories: Type 1: shallow, Type 2: central, Type 3: deep, and Type 4: diffuse. We examined associations between these Types and clinico-pathological factors, including prognosis.

RESULTS

Forty-five (38%) specimens had no residual tumor cells in the mucosal layer. The adventitia layer displayed the lowest residual tumor cell frequency (18%) among all layers. Types 1, 2, 3, and 4 residual tumor patterns were found in 49 (41%), 33 (28%), 9 (8%), and 29 (24%) patients, respectively. Type 4 showed the maximum standard uptake value after NAC; Types 3 and 4 had higher ratios of venous invasion than Type 1 or 2. Patients with Type 3 or 4 more frequently developed pleural dissemination or distant metastasis than patients with Type 1 or 2. Survival was similar among the 4 Types.

CONCLUSIONS

After NAC for locally advanced esophageal cancer, the shallow residual tumor pattern was most common, but approximately 40% of specimens showed no tumor cells in the mucosal layer. Deep and diffuse remnant patterns were associated with high risks of pleural dissemination and distant metastasis.

Convolutional Neural Network Can Recognize Drug Resistance of Single Cancer Cells

It is known that single or isolated tumor cells enter cancer patients' circulatory systems. These circulating tumor cells (CTCs) are thought to be an effective tool for diagnosing cancer malignancy. However, handling CTC samples and evaluating CTC sequence analysis results are challenging. Recently, the convolutional neural network (CNN) model, a type of deep learning model, has been increasingly adopted for medical image analyses. However, it is controversial whether cell characteristics can be identified at the single-cell level by using machine learning methods. This study intends to verify whether an AI system could classify the sensitivity of anticancer drugs, based on cell morphology during culture. We constructed a CNN based on the VGG16 model that could predict the efficiency of antitumor drugs at the single-cell level. The machine learning revealed that our model could identify the effects of antitumor drugs with ~0.80 accuracies. Our results show that, in the future, realizing precision medicine to identify effective antitumor drugs for individual patients may be possible by extracting CTCs from blood and performing classification by using an AI system.

Peritumoral Lymphatic Vessels Associated with Resistance to Neoadjuvant Chemotherapy and Unfavorable Survival in Esophageal Cancer

BACKGROUND

Peri- or intra-tumor lymphangiogenesis is induced in several types of cancer. However, the significance of peritumoral lymphatic vessels (LVs) in esophageal cancer (EC) remains to be clarified.

METHODS

This study included 162 eligible EC patients with or without neoadjuvant chemotherapy (NAC). The numbers of non-tumoral and peritumoral LVs were counted in resected specimens based on podoplanin immunostaining. The association between peritumoral LV number and clinicopathologic parameters, including tumor heterogeneity as measured by positron emission tomography, NAC response, and patient survival were analyzed.

RESULTS

In non-NAC patients, the number of peritumoral LVs was highest in the lamina propria mucosa (LPM), followed by non-tumoral LVs in the LPM, peritumoral LVs in the submucosa (SM), and non-tumoral LVs in the SM. The patients with a low number of peritumoral LVs in the LPM versus those with a high number constituted a larger fraction of the NAC patients (67.8% vs. 50.0%; P = 0.022) and had a poorer pathologic response to NAC (grades 0-1a: 68.8% vs. 47.2%; P = 0.035), as well as greater tumor heterogeneity and worse survival (5-year overall survival: 50.6% vs. 72.8%; P = 0.0097). The number of peritumoral LVs in the LPM was identified as an independent prognostic factor with the highest hazard ratio (HR) of overall survival (HR 2.06; P = 0.0049) in the multivariate analysis.

CONCLUSION

For EC patients, peritumoral LVs in the LPM layer are associated with tumor heterogeneity, response to NAC, and unfavorable survival.

The Prognostic Impact of Leucine-Rich α-2-Glycoprotein-1 in Cholangiocarcinoma and Its Association With the IL-6/TGF-β1 Axis

BACKGROUND

Leucine-rich α-2-glycoprotein-1 (LRG) has been found to participate in the development of various cancers through its involvement in TGF-β1-induced epithelial-mesenchymal transition (EMT) and/or angiogenesis and can be induced by inflammatory cytokines, such as IL-6. As we previously showed the implication of IL-6/TGF-β axis in EMT of cholangiocarcinoma cells, we herein explored the prognostic impact of LRG in postoperative intrahepatic cholangiocarcinoma (ICC) and assessed the association between tumor LRG and factors such as TGF-β1, IL-6, and the tumor microvessel density.

METHODS

We determined the expression of LRG, IL-6, TGF-β1, and CD31 in cancer tissues from 50 ICC patients by immunohistochemistry and analyzed their association with the prognosis.

RESULTS

The LRG expression was closely associated with recurrence-free survival (RFS) and overall survival (OS) in postoperative ICC. A multivariate Cox regression model indicated that LRG as an independently associated with poor RFS (hazard ratio = 2.4339, P = 0.0354) and OS (hazard ratio = 2.8892, P = 0.0268). The LRG expression was significantly associated with the expression of TGF-β1 (P = 0.0003) and IL-6 (P = 0.0164).

CONCLUSIONS

The upregulation of LRG in tumors was an independent prognostic factor in patients with postoperative ICC. LRG was closely associated with the TGF-β1 expression and seems to be an important member of the IL-6/TGF-β1 axis.

A rare case of pelvic bronchogenic cyst treated by laparoscopic surgery

A 31-year-old man with pain in his thigh was diagnosed with a benign presacral cystic mass. We performed laparoscopic subtotal resection of the cyst utilizing mobilization of a total mesorectal excision procedure used in low anterior resection for rectal cancer. Histopathological findings showed that the cystic lumen of the specimen was lined with pseudostratified columnar ciliated epithelium and had glandular structures and smooth muscle in its wall, leading to a diagnosis of bronchogenic cyst. The postoperative course was uneventful, and as of 6 months after surgery, the patient was doing well with no evidence of recurrence.