Multicenter Prospective Cohort Study of Neoadjuvant Chemotherapy for Borderline Resectable Pancreatic Cancer (YPB-001)

OBJECTIVES

The present multicenter prospective observational study investigated the effectiveness and safety of neoadjuvant chemotherapy (NAC) for patients with borderline resectable pancreatic cancer (BRPC) and those with RPC contacting major vessels, with respect to a historical control of upfront surgery.

MATERIALS AND METHODS

Patients with BRPC and RPC contacting major vessels were prospectively registered and administered NAC with durations and regimens determined by the corresponding treating physician. Our primary aim was to assess the R0 resection rate, and secondary aim was to evaluate safety, resection rate, time to treatment failure, overall survival, and response rate.

RESULTS

Fifty of 52 enrolled patients were analyzed; 2 with serious comorbidities died during treatment. Thirty-one patients underwent resection, with R0 resection being achieved in 26 (52% of total and 84% of all resected cases). Univariate and multivariate analyses indicated age (≥75 years) as the only independent predictor of nonresection. Median progression-free survival and median survival time were longer in the prospective cohort than in the historical cohort.

CONCLUSIONS

Overall, NAC for BRPC in real-world setting might yield R0 resection rates similar to those reported in previous clinical studies. Development of safe regimens and management strategies that can maintain treatment intensity in geriatric patients is warranted.

Treatments and prognostic factors for bone and soft tissue sarcoma in non-urban areas in Japan

BACKGROUND

Although bone and soft tissue sarcoma is recognized as a rare cancer that originates throughout the body, few comprehensive reports regarding it have been published in Japan.

PATIENTS AND METHODS

Bone and soft tissue sarcomas were tabulated from the Cancer Registries at eight university hospitals in the Chugoku-Shikoku region. Prognostic factors in cases were extracted in a single facility and have been analyzed.

RESULTS

From 2016 to 2019, 3.4 patients with bone and soft tissue sarcomas per a general population of 100,000 were treated at eight university hospitals. The number of patients who underwent multidisciplinary treatment involving collaboration among multiple clinical departments has been increasing recently. In the analysis carried out at a single institute (Ehime University Hospital), a total of 127 patients (male/female: 54/73) with an average age of 67.0 y (median 69.5) were treated for four years, with a 5-year survival rate of 55.0%. In the analysis of prognostic factors by multivariate, disease stage and its relative treatment, renal function (creatinine), and a patient's ability of self-judgment, and a patient's mobility and physical capability were associated with patient prognosis regarding bone and soft tissue sarcomas. Interestingly, age did not affect the patient's prognosis (> 70 vs ≦ 70).

CONCLUSIONS

Physical and social factors may affect the prognosis of patients with bone and soft tissue sarcomas, especially those living in non-urban areas.

Mass, Spectroscopy, and Two-Neutron Decay of ^{16}Be

The structure and decay of the most neutron-rich beryllium isotope, ^{16}Be, has been investigated following proton knockout from a high-energy ^{17}B beam. Two relatively narrow resonances were observed for the first time, with energies of 0.84(3) and 2.15(5) MeV above the two-neutron decay threshold and widths of 0.32(8) and 0.95(15) MeV, respectively. These were assigned to be the ground (J^{π}=0^{+}) and first excited (2^{+}) state, with E_{x}=1.31(6)  MeV. The mass excess of ^{16}Be was thus deduced to be 56.93(13) MeV, some 0.5 MeV more bound than the only previous measurement. Both states were observed to decay by direct two-neutron emission. Calculations incorporating the evolution of the wave function during the decay as a genuine three-body process reproduced the principal characteristics of the neutron-neutron energy spectra for both levels, indicating that the ground state exhibits a strong spatially compact dineutron component, while the 2^{+} level presents a far more diffuse neutron-neutron distribution.

High serum proteinase-3 levels predict poor progression-free survival and lower efficacy of bevacizumab in metastatic colorectal cancer

BACKGROUND

To improve the prognosis of patients with metastatic colorectal cancer (mCRC), investigating predictive biomarkers of their prognosis and chemotherapeutic responsiveness is necessary. This study aimed to analyze the clinical significance of serum proteinase-3 (PRTN3) as a predictor for prognosis and chemosensitivity, especially to bevacizumab therapy, in mCRC.

METHODS

This single-center retrospective observational study enrolled 79 patients with mCRC in our hospital and 353 patients with colorectal cancer in the TCGA database. Preoperative serum PRTN3 levels were measured using an enzyme-linked immunosorbent assay. The clinicopathological characteristics and prognosis according to serum PRTN3 levels were then evaluated. PRTN3 expression in tumor and stromal cells was evaluated immunohistochemically. The impact of PRTN3 levels on angiogenesis and bevacizumab sensitivity was evaluated using the tube formation assay.

RESULTS

Serum PRTN3 levels were an independent poor prognostic factor for progression-free survival (PFS) (hazard ratio, 2.082; 95% confidence interval, 1.118-3.647; P=0.010) in patients with mCRC. Similarly, prognostic analysis with TCGA data sets showed poorer overall survival in patients with PRTN3 expression than that in patients without PRTN3 expression, especially in patients with stage IV. Immunohistochemical analysis of resected specimens revealed that stromal neutrophils expressed PRTN3, and their expression level was significantly correlated with serum PRTN3 levels. Interestingly, the effectiveness of first-line chemotherapy was significantly poorer in the high serum PRTN3 level group. High serum PRTN3 was significantly associated with poor PFS (hazard ratio, 3.027; 95% confidence interval, 1.175-7.793; P=0.0161) in patients treated with bevacizumab, an anti-angiogenic inhibitor. The tube formation assay revealed that PRTN3 administration notably augmented angiogenesis while simultaneously attenuating the anti-angiogenic influence exerted by bevacizumab therapy.

CONCLUSIONS

Serum PRTN3 levels could be a novel predictive biomarker of PFS of first-line chemotherapy, especially for bevacizumab therapy, in patients with mCRC.

Effects of Extended Fixation on Advanced Gastric Cancer HER2 Status Assessment Using IHC and FISH

BACKGROUND/AIM

In gastric cancer, accurate determination of human epidermal growth factor receptor type 2 (HER2) status is crucial for treatment decision-making. However, the optimal formalin fixation time of gastric cancer specimens for HER2 status determination remains unestablished. Here, we investigated real-world data on formalin overfixation and its effect on HER2 status determination in gastric cancer.

PATIENTS AND METHODS

We comprehensively analyzed HER2 testing results in 228 gastric cancer specimens, including those subjected to formalin overfixation. Subsequently, we divided 52 resected specimens of advanced gastric cancer into three groups and studied the effects of short-term (6-72 h) and long-term (1 and 2 weeks) fixation on HER2 status determination using immunohistochemistry (IHC) and fluorescence in situ hybridization (FISH).

RESULTS

A total of 21.5% (49/228) of the specimens were HER2-positive, whereas 78.5% (179/228) were negative. Among the HER2-negative specimens, no biopsies were overfixed, whereas 12.5% (9/72) of the surgical resection specimens were overfixed. The HER2 status of the 6-72-h group was 82.7% and 76.9% identical to that of the 1- and 2-week groups, when determined using IHC, and 73.1% and 36.5%, when determined using FISH, respectively. However, HER2 determination was not feasible in 26.9% and 63.5% of the specimens in the 1- and 2-week groups, respectively.

CONCLUSION

Formalin overfixation may hinder the determination of HER2 status and should be avoided in gastric cancer sample preparation.

Effect of Paxillin Expression and Phosphorylation on Colorectal Cancer Prognosis and Metastasis

BACKGROUND/AIM

Colorectal cancer (CRC) is the third most common cancer worldwide, and metastasis is strongly associated with poor prognosis in patients with CRC. We have previously found that the expression and phosphorylation of paxillin (PXN) play an important role in the metastatic potential of breast cancer. This study examined the potential role of PXN in CRC metastasis.

MATERIALS AND METHODS

Resected tumor specimens from 92 patients with CRC were subjected to immunohistochemical analysis of PXN levels. Three human CRC cell lines, HCT116, LoVo, and SW480 were used for scratch and transwell invasion assays to examine the effects of PXN over-expression. RNA sequencing was performed to obtain the expression profiles under PXN over-expression.

RESULTS

High levels of PXN were significantly correlated with advanced stage, higher carcinoembryonic antigen and carbohydrate antigen 19-9 levels, and poorer overall survival. The migration ability of CRC cells was enhanced by exogenous PXN over-expression, but this enhancement was not observed in cells harboring exogenously mutated PXN at Tyr31 or Tyr88 phosphorylation sites. In PXN-over-expressing cells, TNF-α signaling via NF-[Formula: see text]B was positively enriched.

CONCLUSION

PXN expression and phosphorylation at Tyr31 or Tyr88 may influence the migration and invasion of CRC cells. PXN expression and phosphorylation at Tyr31 or Tyr88 are promising targets for evaluating prognosis and treating CRC.

Laparoscopic spleen-preserving distal pancreatectomy: A novel technique with splenic artery resection and splenic vein preservation

INTRODUCTION

Laparoscopic spleen-preserving distal pancreatectomy (LSDP) is widely performed to treat benign and low-grade malignant diseases. Although preservation of splenic vessels may be desirable considering the risk of postoperative complications, it is sometimes difficult due to tumor size, inflammation, and proximity of the tumor and splenic vessels. Herein, we present the first case of LSDP with splenic artery resection and splenic vein preservation.

MATERIALS AND SURGICAL TECHNIQUE

A 40-year-old woman with a pancreatic tumor was referred to our hospital. Contrast-enhanced computed tomography (CT) revealed a tumor in the pancreatic tail that was in contact with the splenic artery and distant from the splenic vein. The splenic artery and vein were separated from the pancreas near the dissection line. The splenic artery was resected after pancreatic dissection using a linear stapler. After the pancreatic tail was separated from the splenic hilum while preserving the splenic vein, the distal side of the splenic artery was resected, and the specimen was removed. The postoperative course was uneventful and the patient was discharged on postoperative Day 9. Four months after surgery, postoperative follow-up CT findings showed neither splenic infarction nor gastric varices.

DISCUSSION

This technique is an alternative method of splenic preservation when there is no attachment of the tumor to the splenic vein or uncontrolled expected bleeding of the splenic artery using the Kimura technique.

Current status of vaccine immunotherapy for gastrointestinal cancers

Recent advances in tumor immunology and molecular drug development have ushered in a new era of cancer immunotherapy. Immunotherapy has shown promising results for several types of tumors, such as advanced melanoma, non-small cell lung cancer, renal cell carcinoma, bladder cancers, and refractory Hodgkin's lymphoma. Similarly, efforts have been made to develop immunotherapies such as adoptive T-cell transplantation, peptide vaccines, and dendritic cell vaccines, specifically for gastrointestinal tumors. However, before the advent of immune checkpoint inhibitors, immunotherapy did not work as well as expected. In this article, we review immunotherapy, focusing on cancer vaccines for gastrointestinal tumors, which generally target eliciting tumor-specific CD8 + cytotoxic T lymphocytes (CTLs). We also review various vaccine therapies and describe the relationship between vaccines and adjuvants. Finally, we discuss prospects for the combination of immunotherapy with immune checkpoint inhibitors.

[A Case of Malignant Lymphoma of the Bile Duct Mimicking Cholangiocarcinoma]

During the postoperative follow-up for adrenal tumor for a 78-year-old male patient, a contrast-enhanced computed tomography scan revealed wall thickness with contrast effect in the cystic duct, enlarged lymph nodes along the ileocecal artery, and nodal shadow in the lower lobe of the left lung. First, the collected bile juice at ERC was submitted to cytology multiple times however, no malignant findings were noted. Next, a staging laparoscopy was performed; but the pathological findings of the enlarged lymph nodes and the abdominal lavage cytology showed no malignancy. A nodule in the lower lobe of the left lung was resected for diagnostic and therapeutic purposes, and the pathological diagnosis was primary adenocarcinoma of the lung. Finally the patient underwent exploratory laparotomy for diagnostic purposes. An intraoperative ultrasound- guided needle biopsy for mass lesion located in the medial section of the left liver was performed, and malignant lymphoma was suspected by the intraoperative pathological diagnosis. Cholecystectomy was performed to confirm the histological type, leading to the diagnosis of diffuse large B cell lymphoma. After surgery, the patient underwent 6 courses of rituximab plus CHOP therapy, and the bile duct stricture was improved.

[A Severe Case of Bleeding from Duodenal Invasion Due to Co-Morbid IPMC with Arcuate Ligament Syndrome and IPDA Aneurysm]

An 81-year-old man with a history of left hemiplegia due to a cerebral hemorrhage was admitted to a clinic because of tarry stools. Endoscopic findings revealed an ulcerative lesion with hemorrhage in the descending duodenum. The patient was transferred to our hospital for treatment. Because endoscopic hemostasis was impossible, interventional radiology(IVR) hemostasis was performed using coil embolization for the feeding artery. Simultaneously, angiography showed stenosis of the root of the celiac axis due to arch ligament syndrome and an aneurysm of the inferior pancreaticoduodenal artery (IPDA). Due to the risk of rebleeding, subtotal stomach-preserving pancreatoduodenectomy was performed after the patient's overall condition had stabilized. Despite dissecting the arcuate ligament, the hepatic artery flow did not improve. Hence, a direct arterial anastomosis between the middle colic artery and the gastroduodenal artery was performed. Furthermore, due to the proximity of the IPDA aneurysm to the superior mesenteric artery, IVR embolization for the IPDA aneurysm was performed on postoperative day 8, and he was transferred to a rehabilitation hospital on postoperative day 57. The pathological result was invasive intraductal papillary mucinous carcinoma(IPMC). The patient has been an outpatient with no recurrence 12 months postoperatively.

Efficacy of Staging Laparoscopy in Patients With Pancreatic Cancer: A Single Center Prospective Cohort Study

BACKGROUND/AIM

Staging laparoscopy (SL) for pancreatic cancer (PC) is considered useful to improve accuracy of staging and resectability. However, given the current accuracy of preoperative imaging, the routine application of SL remains unclear. Therefore, we aimed to investigate the importance of SL in patients with PC without radiological distant metastasis.

PATIENTS AND METHODS

This was a prospective, cohort, observational study. SL was performed in all patients with PC without radiological distant metastasis before pancreatectomy or chemotherapy at the Yamaguchi University Hospital.

RESULTS

Between July 2020 and March 2023, 55 patients underwent SL with peritoneal cytology. The median age was 71, with 53% male patients. SL revealed occult metastasis in six (11%) patients including positive peritoneal cytology (n=6), and peritoneal dissemination (n=1). The resectability of unresectable locally advanced (UR-LA) was associated with a significantly increased risk of occult metastasis (p=0.0211). The median operative time was 40 min, and the median volume of blood loss was 3 ml. There were no severe complications (Clavien-Dindo III or higher).

CONCLUSION

SL with peritoneal cytology regardless of previous abdominal surgery is safe and effective to determine accurate staging. Therefore, SL with peritoneal cytology should be considered for patients with PC without radiological distant metastasis, especially in those with UR-LA.

A novel prediction model of pancreatic fistula after pancreaticoduodenectomy using only preoperative markers

BACKGROUND

Since clinically relevant postoperative pancreatic fistula (CR-POPF) can cause intra-abdominal hemorrhage and abscesses, leading to surgery-related deaths after pancreaticoduodenectomy (PD), its preoperative prediction is important to develop strategies for surgical procedures and perioperative management. This study aimed to establish a novel prediction model for CR-POPF using preoperative markers.

METHODS

On a training set of 180 patients who underwent PD at the Yamaguchi University Hospital, a combination of CR-POPF predictors were explored using the leave-one-out method with a unique discrete Bayes classifier. This predictive model was confirmed using a validation set of 366 patients who underwent PD at the Osaka University Hospital.

RESULTS

In the training set, CR-POPF occurred in 60 (33%)　of 180 patients and 130 (36%)　of 366 patients in the validation set using selected markers. In patients with pancreatic ductal adenocarcinoma (PDAC), the main pancreatic duct (MPD) index showed the highest prognostic performance and could differentiate CR-POPF with 87% sensitivity and 81% specificity among 84 patients in the training set. In the validation set, the sensitivity and specificity of the MPD index-based model for 130 PDAC samples were 93% and 87%, respectively. In patients with non-PDAC, the MPD index/body mass index (BMI) combination showed the highest prognostic performance and could differentiate CR-POPF with 84% sensitivity and 57% specificity among 96 patients in the training set. In the validation set, the sensitivity and specificity of the MPD index/BMI-based model for 236 non-PDAC samples were 85% and 53%, respectively.

CONCLUSION

We developed a novel prediction model for pancreatic fistulas after PD using only preoperative markers. The MPD index and MPD index/BMI combination will be useful for CR-POPF assessment in PDAC and non-PDAC samples, respectively.

IL-6 Levels Correlate with Prognosis and Immunosuppressive Stromal Cells in Patients with Colorectal Cancer

BACKGROUND

The prognosis for patients with colorectal cancer (CRC) is determined by tumor characteristics as well as the host immune response. This study investigated the relationship between an immunosuppressive state and patient prognosis by evaluating the systemic and tumor microenvironment (TME) interleukin (IL)-6 levels.

METHODS

Preoperative serum IL-6 levels were measured using an electrochemiluminescence assay. Expression of IL-6 in tumor and stromal cells was evaluated immunohistochemically in 209 patients with resected CRC. Single-cell analysis of tumor-infiltrating immune cells was performed using mass cytometry in 10 additional cases.

RESULTS

Elevated serum IL-6 levels were associated with elevated stromal IL-6 levels and a poor prognosis for patients with CRC. High IL-6 expression in stromal cells was associated with low-density subsets of CD3+ and CD4+ T cells as well as FOXP3+ cells. Mass cytometry analysis showed that IL-6+ cells among tumor-infiltrating immune cells were composed primarily of myeloid cells and rarely of lymphoid cells. In the high-IL-6-expression group, the percentages of myeloid-derived suppressor cells (MDSCs) and CD4+FOXP3highCD45RA- effector regulatory T cells (eTreg) were significantly higher than in the low-IL-6-expression group. Furthermore, the proportion of IL-10+ cells in MDSCs and that of IL-10+ or CTLA-4+ cells in eTregs correlated with IL-6 levels.

CONCLUSION

Elevated serum IL-6 levels were associated with stromal IL-6 levels in CRC. High IL-6 expression in tumor-infiltrating immune cells also was associated with accumulation of immunosuppressive cells in the TME.

Current progress in perioperative chemotherapy for biliary tract cancer

Biliary tract cancer (BTCs) is a heterogeneous malignancy divided into cholangiocarcinoma, gallbladder cancer, and ampullary cancer. Due to little or no symptoms, most patients with BTCs are diagnosed with unresectable or metastatic disease. Only 20%-30% of all BTCs are suitable for potentially resectable diseases. Although radical resection with a negative surgical margin is the only potentially curative method for BTCs, most patients develop postoperative recurrence, which is associated with poor prognosis. Therefore, perioperative treatment is necessary to improve survival. There are very few randomized phase III clinical trials of perioperative chemotherapy due to the relative rarity of BTCs. Adjuvant chemotherapy with S-1 for patients with resected BTC significantly increased overall survival compared with upfront surgery in a recent ASCOT trial. In East Asia, S-1 is currently considered the standard adjuvant chemotherapy, while capecitabine may still be used in other areas. Since then, our phase III trial (KHBO1401), gemcitabine and cisplatin plus S-1 (GCS) has become the standard chemotherapy for advanced BTCs. GCS not only improved overall survival but demonstrated a high response rate. The efficacy of GCS as a preoperative neoadjuvant chemotherapy for resectable BTCs has been investigated in a randomized phase III trial (JCOG1920) in Japan. In this review, we summarize the current and ongoing clinical trials focusing on adjuvant and neoadjuvant chemotherapy for BTCs.

The tumor immune microenvironment in pancreatic cancer and its potential in the identification of immunotherapy biomarkers

INTRODUCTION

Pancreatic cancer (PC) has an extremely poor prognosis, even with surgical resection and triplet chemotherapy treatment. Cancer immunotherapy has been recently approved for tumor-agnostic treatment with genome analysis, including in PC. However, it has limited efficacy.

AREAS COVERED

In addition to the low tumor mutation burden, one of the difficulties of immunotherapy in PC is the presence of abundant stromal cells in its microenvironment. Among stromal cells, cancer-associated fibroblasts (CAFs) play a major role in immunotherapy resistance, and CAF-targeted therapies are currently under development, including those in combination with immunotherapies. Meanwhile, microbiomes and tumor-derived exosomes (TDEs) have been shown to alter the behavior of distant receptor cells in PC. This review discusses the role of CAFs, microbiomes, and TDEs in PC tumor immunity.

EXPERT OPINION

Elucidating the mechanisms by which CAFs, microbiomes, and TDEs are involved in the tumorigenesis of PC will be helpful for developing novel immunotherapeutic strategies and identifying companion biomarkers for immunotherapy. Spatial single-cell analysis of the tumor microenvironment will be useful for identifying biomarkers of PC immunity. Furthermore, given the complexity of immune mechanisms, artificial intelligence models will be beneficial for predicting the efficacy of immunotherapy.

A phase I study of a novel therapeutic vaccine as perioperative treatment for patients with surgically resectable hepatocellular carcinoma: The YCP02 trial

BACKGROUND

Developing effective adjuvant therapies is essential for improving the surgical outcomes in patients with hepatocellular carcinoma (HCC). Immunotherapy against HCC has become a promising strategy; however, only approximately 30% of all HCC patients respond to immunotherapy. Previously, we generated the novel therapeutic vaccine comprising multi-HLA-binding heat shock protein (HSP)70/glypican-3 (GPC3) peptides with a novel adjuvant combination of hLAG-3Ig and poly-ICLC. We also confirmed the safety of this vaccination therapy, as well as its capacity for the effective induction of immune responses in a previous clinical trial.

METHODS

In this phase I study, we administered this vaccine intradermally six times before surgery and ten times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary endpoints of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin and eosin staining and immunohistochemistry for HSP70, GPC3, CD8 and PD-1.

RESULTS

Twenty HLA-matched patients received this vaccination therapy with an acceptable side-effect profile. All patients underwent planned surgery without vaccination-related delay. Immunohistochemical analyses revealed that potent infiltration of CD8+ T cells into tumors with target antigen expression was observed in 12 of 20 (60%) patients.

CONCLUSIONS

This novel therapeutic vaccine was safe as perioperative immunotherapy for patients with HCC and has the potential to strongly induce CD8+ T cells infiltration into tumors. This article is protected by copyright. All rights reserved.

Double cancer of primary hepatic angiosarcoma and hepatocellular carcinoma treated with atezolizumab plus bevacizumab

AIM

Primary hepatic angiosarcoma (PHA) is extremely rare, and its imaging findings are similar to those of other liver tumors including hepatocellular carcinoma (HCC). Here, we report a case of hepatitis C virus (HCV)-related HCC followed by PHA that showed remarkable clinical response to atezolizumab plus bevacizumab (Atezo/Bev) therapy.

CASE PRESENTATION

A 78-year-old man with recurrent HCC had a liver tumor with lymphadenopathy. Although considered as HCC recurrence, microscopic examination of the resected liver and lymph node showed PHA. Three months later, a solitary lung nodule was newly detected and subsequently resected. The pathological diagnosis was poorly differentiated HCC. Therefore, the patient was finally diagnosed with double cancer of PHA and HCC. Thereafter, he developed a new liver tumor with lymphadenopathy and received Atezo/Bev therapy. Liver tumor biopsy was carried out before the treatment. The pathological diagnosis was angiosarcoma. The patient showed a partial response after two courses of Atezo/Bev therapy.

CONCLUSION

To our best knowledge, this report is the first case to present HCV-related HCC followed by PHA and to show that Atezo/Bev therapy is beneficial for PHA.

Anti-VEGF and Anti-EGFR Antibody Therapy on T-Cell Infiltration and TCR Variation in Metastatic Colorectal Cancer

BACKGROUND/AIM

Chemotherapy combined with anti-EGFR or anti-VEGF monoclonal antibodies (mAb) is widely used to treat patients with metastatic colorectal cancer (mCRC). Here, we investigated the effects of these antibodies on T-cell infiltration and T-cell receptor (TCR) repertoire variation in CRC liver metastases.

MATERIALS AND METHODS

Ten patients with mCRC received chemotherapy in combination with anti-EGFR (n=6) or anti-VEGF (n=4) mAb. T-cell infiltration was examined for CD3 and CD8 by carrying out immunohistochemistry on biopsy or surgical specimens from liver metastases before and after treatment. TCR repertoire analysis was carried out on specimens with post-treatment CD3⁺ T-cell infiltration.

RESULTS

T-cell infiltrations were approximately 83% (5/6) and 50% (2/4), following treatment with anti-EGFR or anti-VEGF mAb, respectively. TCR repertoire analysis revealed higher clonality and lower diversity of TCR alpha and beta (TRA and TRB) in the anti-VEGF mAb group than that in the anti-EGFR group mAb. Furthermore, the percentage of the common TCR clones between infiltrating T cells and T cells in peripheral blood was significantly lower in the anti-VEGF mAb group compared to that in the anti-EGFR mAb group.

CONCLUSION

The population of T cells infiltrating liver metastases in the anti-VEGF mAb group differed from that in the anti-EGFR mAb group.

Association between a single nucleotide polymorphism in the R3HCC1 gene and irinotecan toxicity

OBJECTIVE

Irinotecan is a useful anticancer drug for colorectal cancer treatment. UGT1A1*28 and *6 gene polymorphisms are known risk factors for irinotecan-associated toxicity. However, severe adverse effects due to irinotecan have been observed even in patients who do not harbor UGT1A1*28 or *6. We investigated gene polymorphisms in the whole exome to identify useful biomarkers for irinotecan toxicity other than UGT1A.

METHODS

A total of 178 patients with metastatic colorectal cancer (mCRC) and 87 patients with pancreatic cancer were treated with FOLFIRI, FOLFOX, FOLFOXIRI, modified FOLFIRINOX, or gemcitabine plus nab-paclitaxel. Genome-wide screening was performed using whole-exome sequencing (WES), and validation analysis was performed using qPCR with a hydrolysis probe.

RESULTS

Using WES after a doublet chemotherapy regimen comprising irinotecan and 5-fluorouracil (n = 15), seven single nucleotide polymorphisms (SNPs) were identified as candidate biomarkers for irinotecan-associated toxicity of neutropenia. Among the seven SNPs, an SNP in R3H domain and coiled-coil containing 1 (R3HCC1; c.919G > A, rs2272761) showed a significant association with neutropenia (>grade 3) after doublet chemotherapy. Patients receiving irinotecan including triplet chemotherapy, FOLFOXIRI for mCRC (n = 23) or modified FOLFIRINOX for pancreatic cancer (n = 40), also showed significant linear trends between R3HCC1 polymorphism and neutropenia (p = 0.017 and 0.046, respectively). No significant association was observed in patients treated with irinotecan-free regimens, FOLFOX for mCRC (n = 66), and gemcitabine plus nab-paclitaxel for pancreatic cancer (n = 47).

CONCLUSION

Thus, an SNP in the R3HCC1 gene may be a useful biomarker for the toxicity of irinotecan-containing chemotherapy for mCRC and pancreatic cancer.

Clinical outcomes of second‑line chemotherapy after gemcitabine and cisplatin plus S‑1 treatment for patients with advanced biliary tract cancer in the KHBO1401‑3A study

Since the completion of the KHBO1401 study, which evaluated the efficacy of the combination of gemcitabine (GEM) and cisplatin (GC) compared with GC plus S‑1 (GCS), GCS has become a standard chemotherapy for patients with advanced biliary tract cancer (BTC). However, there are currently no data revealing second‑line therapy options after GCS. The present study aimed to evaluate the survival outcomes of patients receiving second‑line chemotherapy for advanced BTC, refractory or intolerant to GCS, using data from the KHBO1401 study. Patients who received a second‑line treatment after GCS chemotherapy between July 2014 and February 2016 were retrospectively studied. Overall survival (OS) was calculated from the day of GCS treatment failure or the first day of second‑line chemotherapy to the final follow‑up date or until death from any cause. Among 83 patients refractory or intolerant to GCS chemotherapy, 51 (61%) received second‑line chemotherapy, including GCS (n=8), GC (n=15), GEM (n=6), GEM plus S‑1 (GS) (n=4) and S‑1 (n=18). The 6‑ and 12‑month OS rates were 66.7 and 44.4%, respectively, following second‑line chemotherapy, and 6.3 and 3.1%, respectively, in the best supportive care group (P<0.0001). In addition, the 12‑ and 24‑month OS rates were 59.3 and 36.2%, respectively, in the multidrug chemotherapy group, and 26.9 and 9.0%, respectively, in the single‑agent chemotherapy group (P=0.0191). These results suggested that second‑line combination chemotherapy is a viable treatment option for patients with advanced BTC that is refractory or intolerant to first‑line GCS therapy.

Serum CCL7 Is a Novel Prognostic Biomarker of Metastatic Colorectal Cancer

BACKGROUND/AIM

Colorectal cancer is the third most common cancer globally, and the poor prognosis of patients with metastatic colorectal cancer (mCRC) warrants urgent attention. We previously obtained 10 candidate serum biomarkers for mCRC. Our aim with this study was to determine the prognostic performance of the pre-treatment serum C-C motif chemokine ligand 7 (CCL7) concentration in patients with mCRC.

PATIENTS AND METHODS

Protein concentrations of CCL7 were examined using ELISA and immunohistochemistry for serum (n=110) and surgical specimens (n=85), respectively, of patients with mCRC. The relationship between protein concentration and prognosis was examined using Cox regression analysis, receiver operator characteristic curve analysis and the Kaplan-Meier method.

RESULTS

The overall survival (OS) of patients with high concentrations of serum CCL7 was significantly poorer than that of patients with low concentrations. Patients with a high CCL7 concentration in the stroma had significantly poorer outcomes than those with a low concentration. The concentrations of carcinoembryonic antigen (CEA) and carbohydrate antigen 19-9 were significantly higher in the high-CCL7 group, compared to those in the low-CCL7 group. Univariate and multivariate analysis revealed that serum CCL7 concentration was a significant prognostic factor for mCRC. The combination of serum CCL and CEA concentrations was also useful in this regard (area under the curve=0.71).

CONCLUSION

The combined pre-treatment serum levels of CCL7 and CEA are useful prognostic biomarkers for mCRC.

Randomized phase III study of gemcitabine, cisplatin plus S-1 versus gemcitabine, cisplatin for advanced biliary tract cancer (KHBO1401- MITSUBA)

BACKGROUND

Gemcitabine/cisplatin (GC) combination therapy has been the standard palliative chemotherapy for patients with advanced biliary tract cancer (BTC). No randomized clinical trials have been able to demonstrate the survival benefit over GC during the past decade. In our previous phase II trial, adding S-1 to GC (GCS) showed promising efficacy and we aimed to determine whether GCS could improve overall survival compared with GC for patients with advanced BTC.

METHODS

We performed a mulitcenter, randomized phase III trial across 39 centers. Enrolled patients were randomly allocated (1:1) to either the GCS or GC arm. The GCS regimen comprised gemcitabine (1000 mg/m² ) and cisplatin (25 mg/m² ) infusion on day 1 and 80 mg/m² of S-1 on days 1-7 every 2 weeks. The primary endpoint was overall survival (OS) and the secondary endpoints were progression-free survival (PFS), response rate (RR), and adverse events (AEs). This study is registered with Clinical trial identification: NCT02182778.

RESULTS

Between July 2014 and February 2016, 246 patients were enrolled. The median OS and 1-year OS rate were 13.5 months and 59.4% in the GCS arm and 12.6 months and 53.7% in the GC arm, respectively (hazard ratio [HR] 0.79, 90% confidence interval [CI]: 0.628-0.996; P = .046 [stratified log-rank test]). Median PFS was 7.4 months in the GCS arm and 5.5 months in the GC arm (HR 0.75, 95% CI: 0.577-0.970; P = .015). RR was 41.5% in the GCS arm and 15.0% in the GC arm. Grade 3 or worse AEs did not show significant differences between the two arms.

CONCLUSIONS

GCS is the first regimen which demonstrated survival benefits as well as higher RR over GC in a randomized phase III trial and could be the new first-line standard chemotherapy for advanced BTC. To exploit the advantage of its high RR, GCS is now tested in the neoadjuvant setting in a randomized phase III trial for potentially resectable BTC.

[Surgical Resection of Gastric GIST Liver Metastasis with Giant Cystic Mass-A Case Report]

The patient is a woman in her 80s who underwent a partial gastrectomy for a gastric GIST 14 years ago. This time, she presented our department with upper abdominal distention and computed tomography revealed an 18 cm-sized cystic lesion in the left lobe of the liver. Since a nodule enhancement was observed in the cyst, malignant disease such as hepatic cystadenocarcinoma could not be ruled out and surgical resection was performed. Pathological examination revealed liver metastasis of gastric GIST. In Japan, only 14 cases have been reported showing such late recurrence with liver metastasis more than 10 years after resection of a primary tumor, including our case. In addition, the cystic finding in this case made preoperative diagnosis difficult because a needle biopsy could not be performed to obtain a pathological diagnosis.

[A Case in Which FOLFOXIRI Was Useful as Preoperative Chemotherapy for Locally Advanced Rectal Cancer with Difficulty in Securing CRM]

The patient is a 65-year-old woman. Colonoscopy performed for close examination of constipation and lower abdominal pain revealed a circumferential type 3 lesion in the rectum Ra. A CT scan showed invasion of the primary lesion into the extramural and sacral front and multiple metastases in the mesorectal lymph nodes but no distant metastasis. Staging laparoscopy was performed. As the mesorectum around the primary lesion was tightly adherent, it was difficult to R0 resection; hence, only construction of colostomy was performed. We have introduced chemotherapy(FOLFOXIRI plus bevacizumab therapy), and 4 courses were administered. Post-treatment CT scan showed that the peri-invasiveness of the primary tumor had disappeared and the enlarged lymph nodes had shrunk. Furthermore, SUVmax of PET-CT for main lesion was decreased, dramatically. On day 109 after the initial surgery, laparoscopic low anterior resection was performed. Although the left hypogastric nerve was resected, other areas could be dissected and R0 resection could be performed. FOLFOXIRI therapy has shown good early-tumor shrinkage and depth of response and may be useful for patients with locally advanced rectal cancer who have difficulty securing circumferential resection margin(CRM).

CD4 and FOXP3 as predictive markers for the recurrence of T3/T4a stage II colorectal cancer: applying a novel discrete Bayes decision rule

Background

We recently reported the relapse-free survival (RFS) significance of the combination of CD4⁺ and forkhead box P3⁺ (FOXP3) T-cell densities identified by immunohistochemistry in patients with stage I, II, and III colorectal cancer (CRC) who underwent curative resections. This study was designed to determine the optimal combination of markers that predict recurrence in patients with T factors of T3/T4a stage II CRC by applying a novel Bayes decision rule.

Methods

Using 137 cancer tissue specimens from T3/T4a stage II patients, 12 clinicopathologic and immune factors were analysed as predictive candidates for recurrence.

Results

Our study showed that the combination of low CD4⁺ and low FOXP3⁺ T-cell densities resulted in extremely poor RFS.

Conclusions

Adjuvant chemotherapy may be considered for patients with a combination of low CD4⁺ and low FOXP3⁺ T-cell densities. The discovery of this new prognostic indicator is important for the appropriate management of patients undergoing curative resection for T3/T4a stage II CRC.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12885-022-10181-7.

[Tumor Immunogenicity and Immune Checkpoint Inhibitors]

Cancer immunotherapy including immune checkpoint inhibitors(ICIs)have established itself as the fourth cancer therapy. However, the response rate of ICIs is still only about 20%, and tumors resistant to ICIs are often so-called"cold-tumor"with low tumor immunogenicity. Therefore, research and development is being conducted worldwide on how to convert cold- tumors into hot-tumors with high immunogenicity. In this paper, we review the relationship between tumor immunogenicity and ICI, as well as therapeutic methods to enhance tumor immunogenicity, and introduce our research about novel cancer peptide vaccination therapy.

Immune Evasion of Hepatoma Cancer Stem-Like Cells from Natural Killer Cells

BACKGROUND

Poor prognosis in liver cancer is due to its high frequency of intrahepatic metastasis. Cancer stem-like cells (CSLCs), which possess the properties of stemness, tumor initiation capability, and resistance to therapy, also exhibit metastatic potential. Immune surveillance plays an important role in the accomplishment of metastasis. Herein, the property of immune evasion in CSLCs was investigated.

METHODS

Sphere cells were induced as CSLCs using a sphere induction medium containing neural survival factor-1. The expression of genes involved in immune evasion was determined using RNA-sequencing for sphere and parental cells followed by validation using flow cytometric analysis and ELISA. Susceptibility to natural killer (NK) cell-mediated cytotoxicity was examined by a chromium release assay. A xenograft model using BALB/c nu/nu mice was used to assess tumor growth. Gene set enrichment analysis was performed for interpreting RNA sequencing.

RESULTS

The cell surface expressions of PD-L1, PD-L2, and CEACAM1 were upregulated and those of ULBP1 and MICA/MICB were downregulated in SK-sphere, CSLCs derived from SK-HEP-1, compared with that in parental cells. Levels of soluble MICA were elevated in conditioned medium from SK-sphere. Expression of HLA class I was not downregulated in SK-sphere. The susceptibilities to NK cell-mediated killing and secreted perforin were significantly lower in both CSLCs derived from SK-HEP-1 and HLE than in parental cells. Tumors formed upon inoculation of SK-sphere in immunodeficient mice harboring NK cells were larger than those formed upon inoculation of parental cells.

CONCLUSION

Human hepatoma cell line-derived CSLCs may possess immune evasion properties, especially from NK cell-mediated immunity.

Surgical shunt ligation for a congenital extrahepatic portosystemic shunt with pulmonary hypertension: A case report

Introduction and importance

Case presentation

Clinical discussion

Conclusion

•

Congenital extrahepatic portosystemic shunt (CEPS) is a rare vascular malformation.

•

Our patient had pulmonary hypertension due to CEPS.

•

Pre- and intraoperative shunt occlusion tests were within acceptable limits.

•

He underwent primary surgical portosystemic shunt ligation.

•

No postoperative complications including acute portal hypertension occurred.

Elevated expression of RAB3B plays important roles in chemoresistance and metastatic potential of hepatoma cells

Background

Cancer stem cells (CSCs) are thought to play important roles in carcinogenesis, recurrence, metastasis, and therapy-resistance. We have successfully induced cancer stem-like sphere cells (CSLCs) which possess enhanced chemoresistance and metastatic potential. To enable the development of targeted therapy against CSLCs, we identified a gene responsible for this phenotype in CSLC.

Methods

Human hepatoma cell line SK-HEP-1 was used for CSLC induction with a unique sphere inducing medium, and HuH-7 cells were used as non-sphere forming cells in the same condition. RNA-sequencing was performed followed by validation with quantitative RT-PCR and western blotting. Knockdown experiments were done by using CRISPR-Cas9 genome-editing, and the rescue experiments were performed using the expressing plasmid vector. Chemoresistance and liver metastasis of the cells, was studied following the splenic injection of cells to severely immune deficient mice and evaluated using the MTS assay. Quantification of exosomes in the medium was done using ELISA.

Results

RAB3B was identified as an up-regulated gene in both CSLCs and prognostically poor hepatocellular carcinoma (HCC) by RNA-sequencing. RAB3B-KD cells showed altered CSLC phenotypes such as sphere formation, chemoresistance, and metastatic potentials, and those were rescued by RAB3B complementation. Increased exosome secretion was observed in CSLCs, and it was not observed in the RAB3B-KD cells. In addition, the RAB3B expression correlated with the expression of ABCG2, APOE, LEPR, LXN, and TSPAN13.

Conclusion

The up regulation of RAB3B may play an important role in the chemoresistance and metastatic potential of CSLCs.

Assessment of Culture/Preservation Conditions of Human Islets for Transplantation

Islet culture before clinical transplantation has been adopted by various centers, but its effect on the survival and function of islets relative to the culture conditions and media needs further assessment. Human islets were cultured or preserved under four different conditions and three media options. Parameters such as recovery, viability, function, islet damage, and gene expressions for markers of hypoxia, and inflammation were assessed after 48-h culture or preservation. Preservation of islets was performed at 4°C in Connaught’s Medical Research Lab (CMRL) and University of Wisconsin (UW) media. Islets were cultured at 22°C, 37°C, and 37°C–22°C in CMRL and PRODO culture media. Islets preserved in UW solution had visually good morphology and exhibited higher recovery with less islet damage compared with the rest of the groups, whereas islets preserved in CMRL at 4°C resulted in poor morphology, recovery, viability, and function compared with the rest of the treatment conditions. Culture at 22°C and 37°C demonstrated an increase in the expression of inflammatory and hypoxia-related genes. In conclusion, islets preserved at 4°C in UW solution showed the best overall outcomes after 48 h compared with islets cultured at 22°C, 37°C, or 37°C–22°C in PRODO. Advancement in islet culture media is warranted to reduce inflammatory gene activation and improve recovery of islets for transplantation.

[A Case of Intrahepatic Cholangiocarcinoma in the Elderly Patient with Curative Resection after Neoadjuvant Chemotherapy]

An 80 year-old woman with anorexia and jaundice was diagnosed with mass-forming intrahepatic cholangiocarcinoma, lymph node metastasis, common hepatic duct strictures, and obstructive jaundice. PET-CT showed FDG accumulation in the primary lesion(SUVmax 19.0)and swollen lymph nodes. Her ADL and major organ functions were judged to be sufficient for treatment. After treatment for jaundice, she received a total of 6 courses of gemcitabine, cisplatin plus S-1(GCS)therapy as neoadjuvant chemotherapy(NAC). Her first treatment was an 80% dose of GCS, but she was subsequently diagnosed with Grade 4 thrombocytopenia(CTCAE v5.0). The dose of gemcitabine was further reduced, and no adverse events of Grade 3 or higher were observed thereafter. After NAC, PET-CT showed decreased FDG accumulation in the primary lesion(SUVmax 3.3)and normalization of FDG accumulation in the lymph nodes. Extended right hepatectomy and biliary reconstruction were performed as radical resection(R0). The final diagnosis was pT2, N0, M0, Stage Ⅱ. After hepatectomy, her anorexia and poor ADL persisted. She was discharged to her home 151 days after her surgery.

[A Case of Pseudo-Meigs' Syndrome Caused by Ovarian Metastasis from Colon Cancer]

This case pertains to a female patient in her 60s who was diagnosed with carcinoma in the cecum with lung, ovarian, and peritoneal metastases. She complained of abdominal distension and poor feeding because her ascites and ovarian metastasis worsened 18 months after chemotherapy initiation. Repeated cytologic examination of the ascitic fluid revealed no malignant cells. Therefore, Pseudo-Meigs' syndrome was suspected. Bilateral salpingo-oophorectomy was performed as palliative surgery because of the patient's reduced capacity to perform activities of daily living(ADL)due to ascites. After palliative surgery, her ascites disappeared, and she was able to better perform ADL. Further, chemotherapy was resumed. The patient remains well 10 months after surgery. This case highlights the importance of considering Pseudo-Meigs' syndrome in patients with massive ascites and ovarian metastasis, because surgical resection can improve their quality of life.

[Postoperative Management of Refractory Pleural Effusion in a Patient with Esophageal Cancer Accompanied by Cirrhosis]

This study reports a case of a 61-year-old man with a chief complaint of anemia. The patient was diagnosed with esophageal cancer(Stage Ⅰ). Preoperative examination revealed alcoholic liver cirrhosis(Child-Pugh A, liver damage B). After a period of abstinence to improve liver function, minimally invasive esophagectomy, retrosternal reconstruction with a gastric tube, and two-field lymph node dissection were performed. The thoracic duct was preserved during the operation. Post- surgery, the bill pleural effusion was increased. Drainage was initiated using thoracentesis with frosemide, spironolactone, and tolvaptan. On post-operating day(POD)35, the patient was discharged; however, right pleural effusion continued to increase. Therefore, cell-free and concentrated reinfusion therapy for right pleural effusion was performed on POD 56. After the treatment, the pleural effusion was well-controlled with 20 mg of frosemide. This case suggested that cell-free and concentrated pleural effusion reinfusion therapy contributed to the management of refractory pleural effusion in patients with esophageal cancer accompanied by cirrhosis.

[A Case of Combined Hepatocellular Carcinoma and Cholangiocarcinoma with Multidisciplinary Treatment Including Lenvatinib]

A 49-year-old man came to our department for the purpose of scrutinizing liver tumor. CA19-9 and CA125 increased, and AFP and PIVKA-Ⅱ were within the normal range. CT showed a large number of early ring enhanced tumor, and a tumor thrombus in the left branch of the portal vein. Tumor biopsy revealed adenocarcinoma. Chemotherapy(gemcitabine, cisplatin plus S-1: GCS)was performed for intrahepatic cholangiocarcinoma(r/o combined hepatocellular carcinoma and cholangiocarcinoma). Lenvatinib was administered because portal vein tumor thrombus and PIVKA-Ⅱ increased after GCS therapy. Two months later, CA19-9 and PIVKA-Ⅱ were decreased and portal vein tumor thrombus was shrunk. Extended left hepatectomy was performed for the purpose of disease control. Histopathological examination revealed some hepatocellular carcinoma components in intrahepatic cholangiocarcinoma. Tumor thrombus was vitrified and necrotic. After hepatectomy, administration of lenvatinib was continued for the residual lesion, and no significant tumor growth was observed.

[A Resected Case of Advanced Lower Rectal Cancer with Neoadjuvant Chemotherapy by FOLFOXIRI plus Cetuximab]

Although the current standard of care for patients with lower rectal cancer in Japan includes total mesorectal resection with lateral lymph node dissection, postoperative local and distant recurrence rates are high. Multidisciplinary treatment is important to improve the prognosis. A man in his 30s was diagnosed with lower rectal cancer due to bloody stool and referred to our department. He was diagnosed as cT3N3M0, cStage Ⅲc with right obturator lymph node metastasis. Four courses of neoadjuvant chemotherapy(NAC)with FOLFOXIRI plus cetuximab were performed. Because Grade 3 neutropenia was observed in the first cycle(CTCAE v5.0), pegfilgrastim was administered in the second and subsequent cycles, and NAC was completed without dose reduction. The patient underwent laparoscopy-assisted intersphincteric rectal resection and D3+rtLD2 dissection. Histopathological resection margins were negative, and the resection was R0. Lymph node metastasis was found only in No. 263d-rt, and the pathological diagnosis was ypT3N3M0, pStage Ⅲc. Histological evaluation of response to treatment was Grade 2. The postoperative course was good and the patient was discharged on postoperative day 15. The patient received 8 courses of adjuvant chemotherapy with mFOLFOX6 from the 7th postoperative week and is alive and recurrence-free 6 months after surgery.

Laparoscopic Sutureless Rectopexy Using a Fixation Device for Complete Rectal Prolapse

BACKGROUND

Complete rectal prolapse (CRP) commonly affects the daily life of older people and has no established operative treatment approach. We describe our simple method of laparoscopic, sutureless rectopexy, involving rectal mobilization (along with its peritoneum bilaterally) and fixation to the sacral promontory using a fixation device. We also present an analysis of short-term outcomes in patients treated using this procedure.

MATERIALS AND METHODS

We retrospectively evaluated 62 patients with CRP, who underwent a laparoscopic rectopexy via tack fixation, between 2004 and 2017. The peritoneum was widely attached near the site of peritoneal reflection, as in rectal cancer surgery. The hypogastric nerve was carefully detached from the front of the sacrum. Keeping the nerve intact, we lifted and mobilized the dissected rectum cranially towards the promontory, and the rectal peritoneum was affixed to the sacrum by applying 2 to 3 fixed tacks bilaterally, using a fixation device.

RESULTS

The median age of the study group was 80 (10 to 91) years. All procedures were successful without serious intraoperative complications; only 1 patient required conversion to open surgery. Median values for operative duration, intraoperative blood loss, and postoperative period of hospitalization were 177 (125 to 441) minutes, 5 (0 to 275) mL, and 7 (3 to 17) days, respectively. Only 6 (9.7%) patients experienced recurrence during the follow-up period.

CONCLUSION

Laparoscopic tacking rectopexy performed using a fixation device for repairing CRP is a simple, safe, and sutureless procedure with no severe complications or mortality.

Pancreatic Cancer Stem-Like Cells With High Calreticulin Expression Associated With Immune Surveillance

OBJECTIVE

Pancreatic cancer stem-like cells (P-CSLCs) are thought to be associated with poor prognosis. Previously, we used proteomic analysis to identify a chaperone pro-phagocytic protein calreticulin (CALR) as a P-CSLC-specific protein. This study aimed to investigate the association between CALR and P-CSLC.

METHODS

PANC-1-Lm cells were obtained as P-CSLCs from a human pancreatic cancer cell line, PANC-1, using a sphere induction medium followed by long-term cultivation on laminin. To examine the cancer stem cell properties, subcutaneous injection of the cells into immune-deficient mice and sphere formation assay were performed. Cell surface expression analysis was performed using flow cytometry.

RESULTS

PANC-1-Lm showed an increased proportion of cell surface CALR-positive and side-population fractions compared with parental cells. PANC-1-Lm cells also had higher frequency of xenograft tumor growth and sphere formation than PANC-1 cells. Moreover, sorted CALRhigh cells from PANC-1-Lm had the highest sphere formation frequency among tested cells. Interestingly, the number of programmed death-ligand 1-positive cells among CALRhigh cells was increased as well, whereas that of human leukocyte antigen class I-positive cells decreased.

CONCLUSION

In addition to the cancer stem cell properties, the P-CSLC, which showed elevated CALR expression on the cell surface, might be associated with evasion of immune surveillance.

Quasifree Neutron Knockout Reaction Reveals a Small s-Orbital Component in the Borromean Nucleus ^{17}B

A kinematically complete quasifree (p,pn) experiment in inverse kinematics was performed to study the structure of the Borromean nucleus ^{17}B, which had long been considered to have a neutron halo. By analyzing the momentum distributions and exclusive cross sections, we obtained the spectroscopic factors for 1s_{1/2} and 0d_{5/2} orbitals, and a surprisingly small percentage of 9(2)% was determined for 1s_{1/2}. Our finding of such a small 1s_{1/2} component and the halo features reported in prior experiments can be explained by the deformed relativistic Hartree-Bogoliubov theory in continuum, revealing a definite but not dominant neutron halo in ^{17}B. The present work gives the smallest s- or p-orbital component among known nuclei exhibiting halo features and implies that the dominant occupation of s or p orbitals is not a prerequisite for the occurrence of a neutron halo.

[A Case of Anastomotic Recurrence of Rectal Cancer Treated by Laparoscopic Total Pelvic Exenteration after Neoadjuvant Chemoradiation]

Patient is 69-year-old man, who underwent a high anterior resection with laparoscopic support for rectal cancer. The patient was diagnosed with anastomotic recurrent rectal cancer after 14 months after surgery. The pelvic MRI scan showed invasion of the prostate and seminal vesicles, so NACRT was performed. Tumors were found to have decreased in size, although there was still some residual invasion of the prostate and seminal vesicle. Laparoscopic total pelvic exenteration (Lap-TPE), and combined excision of the anal elevator muscle and bladder were performed. Preoperative diagnosis was ycT4b, N0, M0, ycStage Ⅱ, and pathological diagnosis was pT4b (prostate and seminal vesicles), INF b, Ly2, v2, Pn1b, pPM0, pDM0, pRM0, and pN0. Laparoscopic surgery allowed to operate safely, with minimal blood loss and a good field of vision. After postoperative adjuvant chemotherapy, lung and liver metastasis appeared after 6 months after surgery, but there was no local recurrence. The patient is treated with chemotherapy, and the metastases are under control. The patient is survive 17 months after Lap-TPE.

[A Case of Gastrointestinal Stromal Tumor of the Lower Rectum That Enabled Minimally Invasive Surgery with Imatinib Mesylate as Neoadjuvant Chemotherapy]

A 67-year-old woman was admitted with melena. A colonoscopy detected a 50 mm submucosal tumor close to the dentate line. We diagnosed the rectal gastrointestinal stromal tumor by EUS-FNA. With the expectation of tumor shrinkage and strong hope of the patient, we started imatinib mesylate as neoadjuvant chemotherapy. A CT scan after 3 months after administration of imatinib mesylate showed the reduction of the size to 35 mm. We operated transanal endoscopic surgery considering the localization of the tumor. From histopathological findings, the tumor was low risk in the modified-Fletcher classification, and low risk in the Miettinen classification. Eight months after the operation, no recurrence was observed without further adjuvant chemotherapy. In this case, we were able to resect the tumor without injuring the film of tumor by operating transanal endoscopic surgery, because of tumor shrinkage with imatinib mesylate as neoadjuvant chemotherapy. I considered that using imatinib mesylate preoperatively was contributed to minimally invasive surgery.

Laparoscopic resection reduces superficial surgical site infection in liver surgery

BACKGROUND

Laparoscopic liver resection is beneficial compared to open liver resection. This study aimed to evaluate whether laparoscopic liver resection could reduce postoperative infections.

METHODS

This study included 125 and 115 patients with liver tumors who underwent open and pure laparoscopic partial resections or left lateral sectionectomies, respectively. Propensity score matching and stabilized inverse probability of treatment weighting were carried out to compare the postoperative infectious complication rates between the two groups.

RESULTS

Patients with tumors located in Couinaud segment 1, 7, or 8; with tumors adjacent to major vessels; or who underwent repeated resections were more likely to receive open resection. After propensity score matching, the superficial incisional surgical site infection rate tended to be lower in the laparoscopic liver resection group than in the open liver resection group. Moreover, overall infectious complication rate and superficial incisional surgical site infection rate were lower in the laparoscopic group (the cohort formed by the stabilized inverse probability of treatment weighting).

CONCLUSIONS

Using the laparoscopic approach for partial resections and left lateral sectionectomies for liver tumors, the superficial incisional surgical site infection rate could be reduced.

Efficacy of intraoperative recurrent laryngeal neuromonitoring during surgery for esophageal cancer

AIM

To evaluate the efficacy of intraoperative neuromonitoring in identifying recurrent laryngeal nerves and decreasing the incidence of nerve injury in minimally invasive esophagectomies for esophageal cancers.

METHODS

A total of 167 minimally invasive esophagectomy patients were retrospectively reviewed. They were divided into intraoperative neuromonitoring (n = 84) and no intraoperative neuromonitoring (n = 83) groups, based on whether or not intraoperative neuromonitoring was used during surgery. We compared short-term surgical outcomes and incidence of recurrent laryngeal nerve palsy between the two groups before and after propensity score matching. The association between the loss of signal and recurrent laryngeal nerve palsy was also evaluated.

RESULTS

The incidence of recurrent laryngeal nerve palsy (grade 2 and higher) was lower in the intraoperative neuromonitoring group than in the no intraoperative neuromonitoring group (6.0% vs 21.2%, P = 0.02). The rate of recurrent laryngeal nerve palsy recovery within 6 months was also significantly higher in the intraoperative neuromonitoring group (87.5% vs 20.0%, P < 0.01). The positive and negative predictive values of intraoperative neuromonitoring for recurrent laryngeal nerve palsy were 60% (9/15) and 86.9% (60/69), respectively. The duration from paralysis to recovery was shorter in recurrent laryngeal nerve palsy cases with negative loss of signal results than in cases with positive loss of signal results (median: 43 days vs 95 days).

CONCLUSION

Intraoperative neuromonitoring is useful in identifying recurrent laryngeal nerves and may aid in reducing the incidence of recurrent laryngeal nerve injury during esophageal surgery.

Surface Localization of the Dineutron in ^{11}Li

The formation of a dineutron in the ^{11}Li nucleus is found to be localized to the surface region. The experiment measured the intrinsic momentum of the struck neutron in ^{11}Li via the (p,pn) knockout reaction at 246  MeV/nucleon. The correlation angle between the two neutrons is, for the first time, measured as a function of the intrinsic neutron momentum. A comparison with reaction calculations reveals the localization of the dineutron at r∼3.6  fm. The results also support the density dependence of dineutron formation as deduced from Hartree-Fock-Bogoliubov calculations for nuclear matter.

[Two Cases of Unresectable Gastric Cancer Where Bleeding Was Controlled by Radiation]

Case 1: The patient was a 74-year-old man with a performance status(PS)of 0. He was referred to our department for pyloric gastric cancer with multiple liver, lung, and lymph node metastases. We started chemotherapy after making the diagnosis of an unresectable gastric cancer. During chemotherapy, the hemoglobin level dropped due to bleeding from the tumor. We attempted endoscopic hemostasis, which was not successful; therefore, we attempted a palliative radiotherapy. The total dose was 30 Gy in 10 Fr and hemostasis was achieved on the 10th day from the start of the radiotherapy. There were no adverse events due to the radiation, and the chemotherapy could be restarted 5 days after the end of the radiotherapy. Case 2: The patient was a 78-year-old man with a PS of 2. He was referred to our department because of vomiting and anemia. As a result of a close inspection, we made the diagnosis of an unresectable gastric body cancer with para-aortic lymph node metastasis and peritoneal dissemination, for which chemotherapy was initiated. Anemia was observed at the first visit, and we started radiotherapy to stop the tumor bleeding. The total dose was 30 Gy in 10 Fr, and hemostasis was achieved on the 12th day. There were no adverse events during the radiotherapy, and chemotherapy could be continued. Palliative radiotherapy is an available method of hemostasis that is less invasive than surgery or transcatheter arterial embolization and can be expected to have a certain effect for gastric cancer bleeding, although it takes several days to obtain a therapeutic effect.

[Recurrent Esophageal Cancer with Metastatic Lymph Node Penetrating in the Reconstructed Gastric Tube-A Case Report]

A 60-year-old man underwent thoracoscopic subtotal esophagectomy and posterior mediastinal gastric tube reconstruction after neoadjuvant chemotherapy. One year and 8 months postoperatively, recurrence was observed in the abdominal lymph nodes around the celiac artery and abdominal aorta. Chemoradiotherapy was initiated, followed by chemotherapy. Two months after the completion of chemoradiotherapy, the patient developed epigastric pain and anorexia because of the necrotic lymph node penetrating the gastric tube with cavity formation. Upper gastrointestinal endoscopy revealed a 25- mm-sized ulcer with central necrotic slough on the posterior wall of the stomach. Abdominal symptoms alleviated after conservative treatment with fasting and administration of antibiotics, and the inflammatory reaction improved. Oral nutritional supplements were started on hospitalization day 7, and abdominal symptoms or inflammatory reactions did not recur after resuming diet. The patient was discharged on hospitalization day 39 when the general condition stabilized. Subsequently, chemotherapy was restarted, and no regrowth of metastatic lesions was observed on endoscopy or CT examination 4 months later. Three years and 8 months after the recurrence, the recurrent disease has been controlled.

Cathepsin B is highly expressed in pancreatic cancer stem-like cells and is associated with patients' surgical outcomes

Cancer stem-like cells (CSLCs) in solid tumors are resistant to conventional chemotherapy and molecularly targeted therapy, which is thought to contribute to cancer recurrence and metastasis. The present study aimed to identify biomarkers for pancreatic CSLCs (P-CSLCs). Using our previously reported methods, P-CSLC-enriched populations were generated from pancreatic cancer cell lines. The protein expression profiles of these populations were compared with those of parental cells using two-dimensional electrophoresis, tandem mass spectrometry, flow cytometry and immunohistochemistry. Protein expression in surgical specimens was also evaluated for relationships with clinical outcomes. A lysosomal cysteine protease, cathepsin B (CTSB), was significantly upregulated in P-CSLCs compared with that in the parental cells, as shown using western blotting. Flow cytometry analysis also confirmed that CTSB was more highly expressed on the surface of P-CSLCs compared with that on parental cells. Moreover, PCLCs had elevated cellular secretions of CTSB compared with the parental cells. Finally, CTSB expression was evaluated in 69 resected tumor specimens, and high expression was associated with the patients' clinicopathological features and surgical outcomes. The present results suggested that CTSB is a biomarker for poor survival in patients with pancreatic cancer, which is possibly associated with P-CSLCs. This novel biomarker may also have potential as a therapeutic target.