Protein phosphatase 6 promotes stemness of colorectal cancer cells.

Colorectal cancer (CRC) remains a significant global health concern, demanding a more profound comprehension of its molecular foundations for the development of improved therapeutic strategies. This study aimed to elucidate the role of protein phosphatase 6 (PP6), a member of the type 2A protein phosphatase family, in CRC. Protein phosphatase 6 functions as a heterotrimer with a catalytic subunit (PP6c), regulatory subunits (PP6Rs; PP6R1, PP6R2, and PP6R3), and scaffold subunits (ANKRD28, ANKRD44, and ANKRD52). Elevated PP6c expression has been identified in CRC tissues compared to normal mucosa, aligning with its potential involvement in CRC pathogenesis. PP6c knockdown resulted in decreased colony-forming ability and in vivo proliferation of various CRC cell lines. Transcriptome analysis revealed that PP6c knockdown resulted in altered expression of genes associated with cancer stemness. Notably, the PP6c-PP6R3 complex is a key player in regulating cancer stem cell (CSC) markers. Additionally, increased PP6c expression was observed in CSC-like cells induced by sphere formation, implicating the role of PP6c in CSC maintenance. This study highlights the role of PP6c in CRC and suggests that it is a potential therapeutic target disrupting a pathway critical for CRC progression and stem cell maintenance.

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.

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.

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

AIM: 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-human leukocyte antigen-binding heat shock protein 70/glypican-3 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 10 times after surgery to patients with untreated, surgically resectable HCC (stage II to IVa). The primary end-points of this study were the safety and feasibility of this treatment. We also analyzed the resected tumor specimens pathologically using hematoxylin-eosin staining and immunohistochemistry for heat shock protein 70, glypican 3, CD8 and programmed death-1. RESULTS: A total of 20 human leukocyte antigen-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.

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 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.

[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.

[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.

[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.

[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.

Novel adjuvant dendritic cell therapy with transfection of heat-shock protein 70 messenger RNA for patients with hepatocellular carcinoma: a phase I/II prospective randomized controlled clinical trial.

INTRODUCTION: A proteomic analysis of hepatocellular carcinoma (HCC) has revealed that Heat Shock Protein 70 (HSP70) is among the cancer antigen proteins of HCC. Moreover, we confirmed that HSP70 was highly expressed in HCC by immunohistochemical staining. Based on these results, we developed an HSP70 mRNA-transfected dendritic cell (DC) therapy for treating unresectable or recurrent HCC, and the phase I trial was completed successfully. Thus, we aimed to investigate the safety and efficacy of this therapy as a postoperative adjuvant treatment after curative resection for HCC to prevent recurrence by conducting a phase I/II randomized controlled clinical trial. METHODS: Patients (n = 45) with resectable HCC of stages II-IVa were registered and randomly assigned into two groups (DC group: 31 patients, control group: 14 patients) before surgery. The primary endpoint was disease-free survival (DFS), and the secondary endpoints were safety and overall survival. The DC therapy was initially administered at approximately 1 week after surgery, and twice every 3-4 weeks thereafter. RESULTS: No adverse events specific to the immunotherapy were observed in the DC group. There was no difference in DFS between the DC and control groups (p = 0.666). However, in the subgroup with HSP70-expressing HCC, DFS of the DC group tended to be better (p = 0.090) and OS of the DC group was significantly longer (p = 0.003) than those of the control group. CONCLUSION: The HSP70 mRNA-transfected DC therapy was performed safely as an adjuvant therapy. The prognosis of HSP70-expressing HCC cases could be expected to improve with this therapy.

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.

Hepatic artery resection and reconstruction using the right gastroepiploic artery during pancreaticoduodenectomy in advanced pancreatic cancer.

PURPOSE: Surgical resection is the only curative treatment for pancreatic cancer. Arterial resection and reconstruction during pancreaticoduodenectomy for advanced pancreatic cancer remain controversial due to a high rate of complications. METHODS: We report two cases of pancreatic cancer with hepatic artery resection and reconstruction using the right gastroepiploic artery during pancreaticoduodenectomy after neoadjuvant therapy. RESULTS: The patients underwent pancreaticoduodenectomy with resection of the right hepatic and common hepatic arteries. Achieving direct anastomosis was difficult; therefore, we planned hepatic artery reconstruction using the right gastroepiploic artery. We performed the reconstruction using an interrupted suture with end-to-end anastomosis. The first patient developed a postoperative pancreatic fistula, while the postoperative course of the second patient was uneventful. However, there were no adverse events related to the arterial reconstruction. R0 resection was achieved, and postoperative computed tomography revealed good patency of the reconstructed artery. CONCLUSION: Hepatic artery reconstruction using the right gastroepiploic artery in pancreatic cancer might be technically safe and might become one of the alternative options.

[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 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 phase I study of multi-HLA-binding peptides derived from heat shock protein 70/glypican-3 and a novel combination adjuvant of hLAG-3Ig and Poly-ICLC for patients with metastatic gastrointestinal cancers: YNP01 trial.

BACKGROUND: This phase I study aimed to evaluate the safety, peptide-specific immune responses, and anti-tumor effects of a novel vaccination therapy comprising multi-HLA-binding heat shock protein (HSP) 70/glypican-3 (GPC3) peptides and a novel adjuvant combination of hLAG-3Ig and Poly-ICLC against metastatic gastrointestinal cancers. METHODS: HSP70/GPC3 peptides with high binding affinities for three HLA types (A*24:02, A*02:01, and A*02:06) were identified with our peptide prediction system. The peptides were intradermally administered with combined adjuvants on a weekly basis. This study was a phase I dose escalation clinical trial, which was carried out in a three patients' cohort; in total, 11 patients were enrolled for the recommended dose. RESULTS: Seventeen patients received this vaccination therapy without dose-limiting toxicity. All treatment-related adverse events were of grades 1 to 2. Peptide-specific CTL induction by HSP70 and GPC3 proteins was observed in 11 (64.7%) and 13 (76.5%) cases, respectively, regardless of the HLA type. Serum tumor marker levels were decreased in 10 cases (58.8%). Immunological analysis using PBMCs indicated that patients receiving dose level 3 presented with significantly reduced T cell immunoglobulin and mucin-domain containing-3 (TIM3)-expressing CD4 + T cells after one course of treatment. PD-1 or TIM3-expressing CD4 + T cells and T cell immunoreceptor with immunoglobulin and ITIM domains (TIGIT)-expressing CD8 + T cells in PBMCs before vaccination were negative predictive factors for survival. CONCLUSIONS: This novel peptide vaccination therapy was safe for patients with metastatic gastrointestinal cancers.

[A Case of Primary Liposarcoma of Pancreas Difficult to Diagnose Preoperatively].

The patient was a woman in her 80s. Operative treatment was performed for papillary thyroid cancer(pT3N0M0)13 years ago. A follow-up CT scan 1 year ago revealed a skin, lung, and lymph node metastasis. At the same time, a tumor with a size of 24 mm was initially observed in the tail of the pancreas, which was considered to be pancreatic metastasis of thyroid papillary cancer and was followed up. Only the pancreatic lesions tended to gradually increase, although other lesions did not increase. Therefore, the patient was referred to our department. It was difficult to diagnose preoperatively. Thus, diagnostic and therapeutic laparoscopic distal pancreatectomy with splenectomy was performed. The pathological diagnosis was dedifferentiated liposarcoma. Postoperatively, a Grade B pancreatic fistula was observed, but the patient recovered conservatively and was discharged on postoperative day 55. Primary liposarcoma of the pancreas is extremely rare, and few cases have been reported. Primary liposarcoma of the pancreas is very difficult to diagnose preoperatively by only diagnostic imaging.

Improved survival of chimeric antigen receptor-engineered T (CAR-T) and tumor-specific T cells caused by anti-programmed cell death protein 1 single-chain variable fragment-producing CAR-T cells.

Chimeric antigen receptor-engineered T (CAR-T)-cell therapy holds significant promise for the treatment of hematological malignancies, especially for B-cell leukemia and lymphoma. However, its efficacy against non-hematological malignancies has been limited as a result of several biological problems characteristic of the tumor microenvironment of solid tumors. One of the main hurdles is the heterogeneous nature of tumor-associated antigens (TAA) expressed in solid tumors. Another hurdle is the inefficient activation and limited persistence of CAR-T cells, mainly as a result of T-cell exhaustion caused by immunosuppressive factors in the tumor microenvironment. In the present study, to address these problems, we engineered CAR-T cells to produce antagonistic anti-programmed cell death protein 1 (PD-1) single-chain variable fragment (scFv), by which PD-1-dependent inhibitory signals in CAR-T cells and adjacent tumor-specific non-CAR-T cells are attenuated. In mouse solid tumor models, PD-1 scFv-producing CAR-T cells induced potent therapeutic effects superior to those of conventional CAR-T cells, along with a significant reduction of apoptotic cell death not only in CAR-T cells themselves but also in TAA-specific T cells in the tumor tissue. In addition, the treatment with anti-PD-1 scFv-producing CAR-T cells resulted in an increased concentration of PD-1 scFv in tumor tissue but not in sera, suggesting an induction of less severe systemic immune-related adverse events. Hence, the present study developed anti-PD-1 scFv-producing CAR-T cell technology and explored its cellular mechanisms underlying potent antitumor efficacy.

Cancer Immunotherapy Targeting Co-signal Molecules.

Great success of immune checkpoint blockade represented by anti-PD-1 monoclonal antibodies (mAbs) has changed a landscape of cancer immunotherapy. There is no doubt about an importance of co-signal molecules as one of the most promising targets in anti-cancer drugs. However, it should be noted that the proportion of patients who have objective and durable responses to immune checkpoint blockade remains less than 30% in majority of cancers. Thus, in addition to refine the usage of existing drugs for checkpoint blockade, identification and characterization of novel checkpoint molecules other than CTLA-4 and PD-1 is a highly anticipated research subject. In addition, agonists of stimulatory co-signal molecules have a potential to further improve anti-tumor effects, rendering them attractive in research and drug development. In this chapter, functions of co-signal molecules in anti-tumor immunity in terms of pre-clinical animal models as well as clinical trials are described.

[Two Cases of Rupture of Elevated Jejunal Varices after Operation for Hilar Cholangiocarcinoma].

Case 1: A 64-year-old man with a chiefcomplaint ofbloody stools was seen in our hospital. He underwent an extended right lobe resection for hilar cholangiocarcinoma 3 years ago and was in the middle of chemotherapy for multiple metastases. Case 2: A 69-year-old man with a chiefcomplaint ofbloody emesis and stools was seen. He underwent left hepatic trisegmentectomy for hilar cholangiocarcinoma and ligation of the right portal vein for postoperative portal venous thrombus 6 months ago. After careful examination, the patients in both cases were diagnosed with bleeding of the jejunal varices formed at the site ofhepaticojejunostomy. The patient in Case 1 underwent percutaneous transhepatic obliteration ofvarices and the patient in Case 2 underwent transileocolic vein obliteration ofvarices. After hepatobiliary pancreatic surgery with biliary tract reconstruction, we should be aware of ectopic varices during differential diagnosis of gastrointestinal bleeding.