Patient survey on cancer genomic medicine in Japan under the national health insurance system.

In Japan, comprehensive genomic profiling (CGP) tests have been reimbursed under the national health care system for solid cancer patients who have finished standard treatment. More than 50,000 patients have taken the test since June 2019. We performed a nation-wide questionnaire survey between March 2021 and July 2022. Questionnaires were sent to 80 designated Cancer Genomic Medicine Hospitals. Of the 933 responses received, 370 (39.7%) were web based and 563 (60.3%) were paper based. Most patients (784, 84%) first learned about CGP tests from healthcare professionals, and 775 (83.1%) gave informed consent to their treating physician. At the time of informed consent, they were most worried about test results not leading to novel treatment (536, 57.4%). On a scale of 0-10, 702 respondents (75.2%) felt that the explanations of the test result were easy to understand (7 or higher). Ninety-one patients (9.8%) started their recommended treatment. Many patients could not receive recommended treatment because no approved drugs or clinical trials were available (102/177, 57.6%). Ninety-eight patients (10.5%) did not wish their findings to be disclosed. Overall satisfaction with the CGP test process was high, with 602 respondents (64.5%) giving a score of 7-10. The major reason for choosing 0-6 was that the CGP test result did not lead to new treatment (217/277, 78.3%). In conclusion, satisfaction with the CGP test process was high. Patients and family members need better access to information. More patients need to be treated with genomically matched therapy.

Human resources for administrative work to carry out a comprehensive genomic profiling test in Japan.

Comprehensive genomic profiling (CGP) tests have been nationally reimbursed in Japan since June 2019 under strict restrictions, and over 46,000 patients have taken the test. Core Hospitals and Designated Hospitals host molecular tumor boards, which is more time-consuming than simply participating in them. We sent a questionnaire to government-designated Cancer Genomic Medicine Hospitals, including all 12 Core Hospitals, all 33 Designated Hospitals, and 117 of 188 Cooperative Hospitals. The questionnaire asked how much time physicians and nonphysicians spent on administrative work for cancer genomic medicine. For every CGP test, 7.6 h of administrative work was needed. Physicians spent 2.7 h/patient, while nonphysicians spent 4.9 h/patient. Time spent preparing for molecular tumor boards, called Expert Panels, was the longest, followed by time spent participating in Expert Panels. Assuming an hourly wage of ¥24,000/h for physicians and ¥2800/h for nonphysicians, mean labor cost was ¥78,071/patient. On a monthly basis, more time was spent on administrative work at Core Hospitals compared with Designated Hospitals and Cooperative Hospitals (385 vs. 166 vs. 51 h/month, respectively, p < 0.001). Consequently, labor cost per month was higher at Core Hospitals than at Designated Hospitals and Cooperative Hospitals (¥3,951,854 vs. ¥1,687,167 vs. ¥487,279/month, respectively, p < 0.001). Completing a CGP test for a cancer patient in Japan is associated with significant labor at each hospital, especially at Core Hospitals. Streamlining the exchange of information and simplifying Expert Panels will likely alleviate this burden.

Impact of combined resection of the internal iliac artery on loss of volume of the gluteus muscles after pelvic exenteration.

PURPOSE: To clarify the influence of additional internal iliac artery (IIA) resection on the loss of the gluteus muscle volume after pelvic exenteration (PE). METHODS: The subjects of this retrospective analysis were 78 patients who underwent PE with or without IIA resection (n = 44 and n = 34, respectively) between 2006 and 2018. The areas of gluteal muscles (GMs) and psoas muscles (PSMs) were calculated using CT images before and 6 months after PE, and the difference was compared. RESULTS: The volumes of the GMs and PSMs were significantly reduced after PE (P < 0.001 and P = 0.005, respectively). In the IIA resection group, the GMs were significantly reduced after surgery, but the PSMs were not. The maximum GM (Gmax) was the most atrophied among the GMs. Multivariable analysis revealed that complete IIA resection was an independent promotor of the loss of volume of the Gmax (P = 0.044). In 18 patients with unilateral IIA resection, the downsizing rate of the Gmax was significantly greater on the resected side than on the non-resected side (P = 0.008). CONCLUSIONS: The GMs and PSMs were significantly smaller after PE. Complete IIA resection reduced the Gmax area remarkably. Preservation of the superior gluteus artery is likely to help maintain Gmax size, suggesting a potential preventative measure against secondary sarcopenia.

Trefoil factor 1 inhibits the development of esophageal adenocarcinoma from Barrett's epithelium.

Trefoil factor family 1 (TFF1) is one of three members of the trefoil factor family that are abundantly expressed in the gastrointestinal mucosal epithelium. Recent studies have shown that TFF1 acts as a tumor suppressor in gastric, pancreatic and hepatocellular carcinogenesis; however, little is known about its function in esophageal carcinogenesis, especially in esophageal adenocarcinoma (EAC). Barrett's epithelium is the metaplastic columnar epithelium of the esophagus and a known premalignant lesion of EAC. To investigate the role of TFF1 in EAC development, a mouse model of Barrett's epithelium was employed, and human specimens of EAC were assessed by immunohistochemistry (IHC) and methylation-specific PCR. Wild-type (WT) mice underwent gastrojejunostomy on the forestomach, resulting in the development of Barrett's epithelium-like (BE-like) epithelium adjacent to the anastomotic site. BE-like epithelium in these mice expressed TFF1, indicating the association of TFF1 with esophageal adenocarcinoma. TFF1-knockout (TFF1KO) mice underwent the same procedure as well, revealing that a deficiency in TFF1 resulted in the development of adenocarcinoma in the anastomotic site, presumably from BE-like epithelium. IHC of human samples revealed strong TFF1 expression in Barrett's epithelium, which was lost in some EACs, confirming the association between TFF1 and EAC development. Aberrant DNA hypermethylation in TFF1 promoter lesions was detected in TFF1-negative human EAC samples, further confirming not only the role of TFF1 in EAC but also the underlying mechanisms of TFF1 regulation. In addition, IHC revealed the nuclear translocation of ß-catenin in human and mouse EAC, suggesting that activation of the Wnt/ß-catenin pathway was induced by the loss of TFF1. In conclusion, these results indicate that TFF1 functions as a tumor suppressor to inhibit the development of esophageal carcinogenesis from Barrett's epithelium.

Trefoil factor family 2 inhibits cholangiocarcinogenesis by regulating the PTEN pathway in mice.

Trefoil factor family 2 (TFF2) is one of three trefoil factor family proteins and is expressed abundantly in the gastrointestinal epithelium. Recent studies have shown that TFF2 acts as a tumor suppressor in gastric and pancreatic carcinogenesis; however, little is known about its function in cholangiocarcinogenesis. To investigate the function of TFF2 in cholangiocellular carcinoma (CCC), immunohistochemistry of surgically resected human CCC samples was performed. TFF2 expression was upregulated in the early stage and lost in the late stage of cholangiocarcinogenesis, suggesting the association of TFF2 and CCC. A TFF2 expression vector was then transfected into a CCC cell line (HuCCT1) in vitro, revealing that TFF2 functions as a tumor suppressor not only by inhibiting proliferation and invasion but also by promoting the apoptosis of cancer cells. In addition, PTEN signaling activity was downregulated by TFF2, suggesting an association between TFF2 and PTEN. Next, hepatic carcinogenesis model mice (KC; albumin-Cre/Lox-Stop-Lox KRASG12D) were bred with TFF2-knockout mice to generate a TFF2-deficient mouse model (KC/TFF2-/-). Although the incidence of hepatocellular carcinoma was not different between KC/TFF2-/- mice and control mice, biliary intraepithelial neoplasm (BilIN), the precursor of CCC, was frequently found in the biliary epithelium of KC/TFF2-/- mice. Immunohistochemistry revealed that BilIN samples from these mice did not express PTEN. In addition, two KC/TFF2-/- mice developed CCC adjacent to BilIN, suggesting that TFF2 functions to inhibit the development of CCC in vivo. These results indicate that TFF2 acts as a tumor suppressor to inhibit the development of CCC by regulating PTEN activity.

Trefoil Factor Family 1 Inhibits the Development of Hepatocellular Carcinoma by Regulating ß-Catenin Activation.

BACKGROUND AND AIMS: Recent studies have suggested that trefoil factor family 1 (TFF1) functions as a tumor suppressor in gastric and pancreatic carcinogenesis. APPROACH AND RESULTS: To investigate the role of TFF1 in hepatocarcinogenesis, we performed immunohistochemical staining of surgically resected human liver samples, transfected a TFF1 expression vector into hepatocellular carcinoma (HCC) cell lines, and employed a mouse model of spontaneous HCC development (albumin-cyclization recombination/Lox-Stop-Lox sequence-Kirsten rat sarcoma viral oncogene homologG12D [KC]); the model mouse strain was bred with a TFF1-knockout mouse strain to generate a TFF1-deficient HCC mouse model (KC/TFF1-/- ). TFF1 expression was found in some human samples with HCC. Interestingly, TFF1-positive cancer cells showed a staining pattern contradictory to that of proliferating cell nuclear antigen, and aberrant DNA hypermethylation in TFF1 promoter lesions was detected in HCC samples, indicating the tumor-suppressive role of TFF1. In vitro, induction of TFF1 expression resulted in impaired proliferative activity and enhanced apoptosis in HCC cell lines (HuH7, HepG2, and HLE). These anticancer effects of TFF1 were accompanied by the loss of nuclear ß-catenin expression, indicating inactivation of the ß-catenin signaling pathway by TFF1. In vivo, TFF1 deficiency in KC mice accelerated the early development and growth of HCC, resulting in poor survival rates. In addition, immunohistochemistry revealed that the amount of nuclear-localized ß-catenin was significantly higher in KC/TFF1-/- mice than in KC mice and that human HCC tissue showed contradictory expression patterns for ß-catenin and TFF1, confirming the in vitro observations. CONCLUSIONS: TFF1 might function as a tumor suppressor that inhibits the development of HCC by regulating ß-catenin activity.

Loss of trefoil factor 1 inhibits biliary regeneration but accelerates the hepatic differentiation of progenitor cells in mice.

Although the regeneration of the adult liver depends on hepatic progenitor cells (HPCs), many uncertainties regarding hepatic regeneration in the injured liver remain. Trefoil factor family 1 (TFF1), a secretory protein predominantly expressed in the gastrointestinal tract, is responsible for mucosal restitution. Here, we investigated the role of TFF1 in liver regeneration using a mouse model of hepatic injury (choline-deficient ethionine-supplemented diet and carbon tetrachloride administration) and genetically engineered mice (TFF1 knockout (TFF1-/-)). Immunohistochemistry analysis of human liver samples revealed TFF1 expression in the hepatocytes close to ductular reaction and the regenerating biliary epithelium in injured liver. The number of cytokeratin 19 (CK19)-positive bile ducts was significantly decreased in the TFF1-/- mice after liver injury. Notch pathway in the TFF1-/- mice was also downregulated. HPCs in the control mice differentiated into biliary cells (CK19+/SRY HMG box 9 (SOX9)+) more frequently. In contrast, HPCs in the TFF1-/- mice more frequently differentiated into a hepatic lineage (alpha fetoprotein+/SOX9+) after acute liver damage. Hepatocyte proliferation was upregulated, and the liver weight was increased in TFF1-/- mice in response to chronic liver damage. Thus, TFF1 is responsible for liver regeneration after liver injury by promoting HPC differentiation into a biliary lineage and inhibiting HPC differentiation into a hepatic lineage.

Cells of origin of pancreatic neoplasms.

Pancreatic ductal adenocarcinoma (PDAC) is a lethal malignant disease associated with poor prognosis, despite recent medical advances. It is of great importance to understand the initial events and cells of origin of pancreatic cancer to prevent the development and progression of PDAC. There are three distinct precursor lesions that develop into PDAC: pancreatic intraepithelial neoplasms (PanINs), intraductal papillary mucinous neoplasms (IPMNs), and mucinous cystic neoplasms (MCNs). Studies on genetically engineered mouse models have revealed that the initiation and development of these lesions largely depend on genetic alterations. These lesions originate from different populations in the pancreas. PanIN development seems to be the result of the transdifferentiation of acinar cells, whereas IPMNs most likely arise from the progenitor niche of the pancreatic ductal epithelium. Pancreatic carcinogenesis is dependent on various events, including gene alterations, environmental insults, and cell types. However, further studies are needed to fully understand the initial processes of pancreatic cancer.

Trefoil factor family 1 expression in the invasion front is a poor prognostic factor associated with lymph node metastasis in pancreatic cancer.

OBJECTIVES: Trefoil Factor Family protein 1 (TFF1) is secreted from mucus-producing cells. The relationship between TFF1 expression and clinical outcome in pancreatic ductal adenocarcinoma (PDAC) remains unknown. We aimed to evaluate the prognostic significance of TFF1 expression in PDAC. METHODS: TFF1 expression was examined on paraffin-embedded sections from 91 patients with resected PDAC using immunohistochemistry. The relationships between TFF1 expression and clinicopathological features were analyzed. RESULTS: Among 91 PDAC patients, 71 patients (79.7%) showed TFF1 expression in cancer cells. In a subgroup of 71 patients, TFF1 expression was predominantly observed in the central part of the tumor, whereas TFF1 expression in the invasion front was reduced in 33 patients (46.4%). A significant correlation between preserved TFF1 expression in the invasion front and lymph node metastasis was observed. Univariate survival analysis revealed that preserved TFF1 expression in the invasion front, positive lymphatic invasion, lymph node metastasis and R1 resection was a significant poor prognostic factor in TFF1-positive PDAC patients. CONCLUSIONS: TFF1 expression is frequently lost or decreased in the invasion front of human PDAC, and preserved TFF1 expression in the invasion front might predict poor survival in patients with PDAC.

A Clear Difference Between the Outcomes After a Major Hepatectomy With and Without an Extrahepatic Bile Duct Resection.

BACKGROUND: The procedure of a simple hepatectomy and a hepatectomy with an extrahepatic bile duct resection and subsequent choledocho-jejunostomy is largely different. However, these two procedures are sometimes included in the same category. There are no studies comparing postoperative course and liver regeneration rate after a major hepatectomy with and without an extrahepatic bile duct resection. METHODS: We retrospectively reviewed medical records of 245 patients who underwent a right hepatectomy (RH, n = 55) or RH with an extrahepatic bile duct resection (RHEBR, n = 190). Postoperative complications, including incidence of posthepatectomy liver failure (PHLF) and hepatic regeneration rates after surgery, were evaluated. RESULTS: The incidence of PHLF was considerably higher in the RHEBR group than in the RH group (39.5 vs. 16.4 %, p = 0.001). The percentage of newly regenerated liver volume after the hepatectomies on postoperative days 6-8 was significantly lower in the RHEBR group than in the RH group (14.0 % in the RH; 7.9 % in the RHEBR group, p < 0.001). Especially type of surgery (RHEBR) was the only independent risk factor for an impaired liver regeneration rate by univariate and multivariate analyses. Furthermore, estimated hepatic regeneration rate by stepwise linear regression analysis in the RHEBR group was 7.1 % lower (95 % confidence interval 1.8-12.3, p = 0.011) than in the RH group. CONCLUSION: These results suggest that the procedure of extrahepatic bile duct resection has a possibility of adverse impact on the postoperative outcome after major hepatectomy.

Nek2 siRNA therapy using a portal venous port-catheter system for liver metastasis in pancreatic cancer.

Nek2 (NIMA-related kinase 2) is a serine-threonine kinase and human homolog of the mitotic regulator NIMA of Aspergillus nidulan. We reported the efficiency of Nek2 siRNA in several cancer xenograft models using cholangiocarcinoma, breast cancer and colorectal cancer. Pancreatic cancer is difficult to treat due to its rapid progression and resistance to chemotherapy. Novel treatments are urgently required to improve survival in pancreatic cancer, and siRNA are a promising therapeutic option. However, finding an in vivo drug delivery system of siRNA remains a major problem for clinical application. In this study, the overexpression of Nek2 was identified in pancreatic cancer cell lines. Nek2 siRNA inhibited tumor growth in a subcutaneous xenograft mouse model of pancreatic cancer, prolonged the survival time in an intraperitoneal xenograft mouse model and efficiently prevented the progression of liver metastasis using a portal venous port-catheter system. Taken together, Nek2 is an effective therapeutic target in pancreatic cancer. An adequate delivery system is considered important in treating advanced pancreatic cancer, such as peritoneal dissemination and liver metastasis. Further investigations are required on the safety and side effects of the portal venous port-catheter system. We hope that Nek2 siRNA will be a novel therapeutic strategy for pancreatic cancer with liver metastasis and peritoneal dissemination.

Effect of Perioperative Synbiotic Treatment on Bacterial Translocation and Postoperative Infectious Complications after Pancreatoduodenectomy.

BACKGROUND/AIMS: This study investigated the effect of perioperative synbiotics on bacterial translocation to mesenteric lymph nodes (MLNs) and occurrence of infectious complications following pancreatoduodenectomy (PD; University Hospital Medical Information Network ID 000003705). METHODS: Patients who were scheduled to undergo PD were randomized to receive preoperative synbiotics or no synbiotics (control group). MLNs were harvested at laparotomy (MLN-1) and after the resection (MLN-2). Blood samples were collected before laparotomy (Blood-1) and on postoperative day 1 (Blood-2). Microorganisms in each sample were detected using a bacterium-specific ribosomal RNA-targeted reverse transcriptase-quantitative polymerase chain reaction. RESULTS: Forty-four patients were included. In all samples, the bacterial detection rate in the MLN-1, MLN-2, Blood-1, and Blood-2 was lower in the synbiotics group than in the control group, although it did not reach a statistically significant difference. There was a significant correlation between the positivity of bacteria in the MLN-2 and Blood-2 samples (p = 0.009). The incidence rate of overall infectious complications was not significantly different between the 2 groups. Among various perioperative factors, the incidence of pancreatic fistula was the only factor that had a significant association with the incidence of infectious complications. CONCLUSION: The preoperative use of synbiotics did not affect the incidence of infectious complications following PD.

The effects of bevacizumab on intestinal anastomotic healing in rabbits.

PURPOSES: The aim of this study was to investigate the effects of the preoperative administration of BV on the healing process of intestinal anastomosis in a rabbit model. METHODS: Twenty male white rabbits were randomly divided into two groups. The control group received saline 1 week before surgery, and the BV group received intravenous BV 1 week before surgery. Each rabbit underwent an enteroenterostomy and a colocolostomy. On postoperative day 7, the bursting pressures of the anastomoses, CD31 and α-smooth muscle actin (α-SMA) staining by immunohistochemistry, the gene expression of α-SMA, and collagen deposition using Picrosirius Red at the site of anastomosis were evaluated. RESULTS: The bursting pressure of small bowel anastomoses was significantly lower in the BV group than in the control group (control 184 ± 10 mmHg vs. BV 140 ± 9 mmHg; p = 0.004). The microvessel counts in the anastomotic tissue were significantly lower in the BV group than in the control group in both the small bowel (p = 0.023) and colon (p = 0.008). The expression of α-SMA, and the degree of collagen deposition decreased in the anastomotic tissue in the BV group compared with the control group. CONCLUSION: The preoperative use of BV may therefore negatively affect the rigidity of intestinal anastomosis.

Prognostic Value of Hepatocyte Growth Factor Receptor Expression in Patients with Perihilar Cholangiocarcinoma.

BACKGROUND: Although an aggressive surgical approach to perihilar cholangiocarcinoma (PHC) has improved survival, a prognosis of advanced PHC remains unsatisfactory. The overexpression of mesenchymal-epithelial transition factor (MET) and recepteur d'origine nantais (RON) has been shown to be associated with poor prognosis in some types of cancer. METHODS: One hundred sixty-nine patients who underwent histologically curative resection for PHC were subjected to immunohistochemical analysis for MET and RON. The association between a positive expression of MET or RON and clinicopathologic features as well as the patients' prognosis were analyzed. RESULTS: There were 27 patients (16 %) who had a positive expression for both MET and RON. Although clinicopathologic features in the either MET- or RON-negative group were not significantly different compared to the both MET- and RON-positive group, the prognosis tended to be worse in the patients with both MET and RON positivity. When the analysis was limited to patients with advanced-stage disease (stage III and IVa), a multivariate analysis revealed that both MET and RON positivity and lymph node metastasis were identified as independent poor prognostic factors. CONCLUSIONS: The overall survival rate for patients with both MET and RON positivity was worse than that with either MET or RON negativity in patients with advanced PHC. The poor prognosis in these patients was not associated with unfavorable clinicopathologic features. The examination of MET and RON expression in PHC may enable a tailored method for patient classification that could not otherwise be achieved using the conventional pathologic classification system.

Does inchinkoto, a herbal medicine, have hepatoprotective effects in major hepatectomy? A prospective randomized study.

OBJECTIVES: This randomized clinical trial was designed to investigate whether inchinkoto has a hepatoprotective effect on postoperative outcome after major hepatectomy. METHODS: Sixty-one patients scheduled for major hepatectomy were randomly assigned to one of two groups in which preoperative inchinkoto was (inchinkoto group, n = 30) or was not (non-inchinkoto group, n = 31) administered. Inchinkoto was administered for at least 7 days before surgery. The primary endpoint was the incidence of post-hepatectomy liver damage. The expression of nuclear factor E2-related factor 2 (Nrf2) and other oxygen stress-related markers in the liver were also determined. RESULTS: There was no significant difference in clinical characteristics between the inchinkoto and non-inchinkoto groups. Serum levels in liver function tests and incidences of post-hepatectomy liver failure did not differ significantly between the two groups. However, there was a significantly higher induction of antioxidant factors in the liver, such as Nrf2 protein and heme oxygenase-1 mRNA, after hepatectomy in the inchinkoto group than in the non-inchinkoto group. CONCLUSIONS: The preoperative administration of inchinkoto did not have a significant impact on the overall outcome of major hepatectomy. However, inchinkoto induced the expression of Nrf2 during hepatectomy and may have exerted an antioxidative effect on the liver.

Inhibition of Toll-like receptor 4 suppresses liver injury induced by biliary obstruction and subsequent intraportal lipopolysaccharide injection.

The objective of this study was to elucidate the role of Toll-like receptor 4 (TLR4) in liver injury induced by biliary obstruction and subsequent intraportal lipopolysaccharide (LPS) infusion in rats. Biliary obstruction often leads to the development of bacterial translocation. Rats were subjected to either a sham operation (Sham group) or bile duct ligation for 7 days (BDL group). Seven days after each operation, LPS (0.5 µg) was injected through the ileocecal vein. In other experiments, rats that had undergone BDL were pretreated, before LPS challenge, with internal biliary drainage (Drainage group); intravenous TAK-242, a TLR4 inhibitor (TAK group); or intravenous GdCl3, a Kupffer cell deactivator (GdCl3 group). The expression of the TLR4 protein and the number of Kupffer cells in the liver were significantly increased in the BDL group compared with the Sham group. These changes were normalized after biliary drainage. The expression of TLR4 colocalized with Kupffer cells, which was confirmed by double immunostaining. Serum levels of liver enzymes and proinflammatory cytokines after intraportal LPS injection were significantly higher in the BDL group than in the Sham group. However, pretreatment with TAK-242 or GdCl3 strongly attenuated these changes to levels similar to those seen with biliary drainage. These results imply that blocking TLR4 signaling effectively attenuates liver damage to the same level as that observed with biliary drainage in rats with BDL and subsequent intraportal LPS infusion. TAK-242 treatment may be used for patients who are susceptible to liver damage by biliary obstruction and endotoxemia.

The determination of bile leakage in complex hepatectomy based on the guidelines of the International Study Group of Liver Surgery.

BACKGROUND: The International Study Group of Liver Surgery (ISGLS) has defined bile leakage as a drain fluid-to-serum total bilirubin concentration (TBC) ratio (the bilirubin ratio) ≥ 3.0. The aim of the present study was to determine the clinical significance of this definition, and to outline characteristics of bile leakage in complex hepatectomy. METHODS: The TBCs of the serum and drain fluid were measured on postoperative days (POD) 1, 3, and 7 in 241 patients who had undergone hepatobiliary resection. The validation of the bilirubin ratio and predictors of bile leakage were retrospectively assessed. RESULTS: Grade A, B, or C bile leakage was found in 23 (9.5 %), 66 (27.4 %), and 0 patients, respectively. The median duration of drainage was 27 days in grade B bile leakage. The sensitivity and specificity of the bilirubin ratio for detecting grade B bile leakage were 59 and 87 %, respectively. The area under the receiver operating characteristics curve of the drain fluid TBC on POD 3 had the highest predictive value: 68 % sensitivity and 76 % specificity for a drain fluid TBC of 3.7 mg/dL. The multivariate analysis demonstrated that operative time, left trisectionectomy, bilirubin ratio, and TBC of the drain fluid on POD 3 were independent predictors of grade B bile leakage. CONCLUSIONS: In complex hepatectomy, bile leakage develops most frequently after left trisectionectomy and often results in a refractory clinical course. The ISGLS biochemical definition is valid, and a combination of bilirubin ratio and drain fluid TBC may enhance risk prediction for grade B bile leakage.

[Concept of perihilar cholangiocarcinoma in the General Rules for Clinical and Pathological Studies on Cancer of the Biliary Tract, 6th edition].

Hilar cholangiocarcinoma is clinically characterized by biliary obstruction in the porta hepatis. Because the boundary between the intrahepatic and extrahepatic bile duct is unclear, hilar cholangiocarcinoma can potentially arise from both ducts. Therefore, the definition of hilar cholangiocarcinoma remains under debate. In November 2013, the 6th edition of the General Rules for Clinical and Pathological Studies on Cancer of the Biliary Tract was released, following the American Joint Committee on Cancer (AJCC) or International Union Against Cancer (UICC) TNM system. In that edition, as an alternative to "hilar cholangiocarcinoma," the new term "perihilar cholangiocarcinoma" is defined as cholangiocarcinoma involving the perihilar bile duct, despite the presence or absence of a significant liver mass component. This definition clearly indicates that some intrahepatic as well as extrahepatic perihilar tumors are involved in the perihilar tumor category. From the clinical point of view, there is no need for a differential diagnosis between intrahepatic or extrahepatic tumors therefore, the new definition is readily applicable in multidisciplinary team management. Japanese clinicians were previously required to distinguish between the proper use of the AJCC/UICC and the Japanese staging systems, but now the current revision will allow the more convenient use of a single, globally standardized staging system in daily practice.

Trefoil factor 1 suppresses stemness and enhances chemosensitivity of pancreatic cancer.

BACKGROUND AND AIMS: Pancreatic cancer is one of the most lethal malignancies, partly due to resistance to conventional chemotherapy. The chemoresistance of malignant tumors is associated with epithelial-mesenchymal transition (EMT) and the stemness of cancer cells. The aim of this study is to investigate the availability and functional mechanisms of trefoil factor family 1 (TFF1), a tumor-suppressive protein in pancreatic carcinogenesis, to treat pancreatic cancer. METHODS: To investigate the role of endogenous TFF1 in human and mice, specimens of human pancreatic cancer and genetically engineered mouse model of pancreatic cancer (KPC/TFF1KO; Pdx1-Cre/LSL-KRASG12D/LSL-p53R172H/TFF1-/-) were analyzed by immunohistochemistry (IHC). To explore the efficacy of extracellular administration of TFF1, recombinant and chemically synthesized TFF1 were administered to pancreatic cancer cell lines, a xenograft mouse model and a transgenic mouse model. RESULTS: The deficiency of TFF1 was associated with increased EMT of cancer cells in mouse models of pancreatic cancer, KPC. The expression of TFF1 in cancer cells was associated with better survival rate of the patients who underwent chemotherapy, and loss of TFF1 deteriorated the benefit of gemcitabine in KPC mice. Extracellular administration of TFF1 inhibited gemcitabine-induced EMT, Wnt pathway activation and cancer stemness, eventually increased apoptosis of pancreatic cancer cells in vitro. In vivo, combined treatment of gemcitabine and subcutaneous administration of TFF1 arrested tumor growth in xenograft mouse model and resulted in the better survival of KPC mice by inhibiting EMT and cancer stemness. CONCLUSION: These results indicate that TFF1 can contribute to establishing a novel strategy to treat pancreatic cancer patients by enhancing chemosensitivity.

TLK1 Inhibition Enhances the Anticancer Effect of Deep UV Irradiation Through CHK1 Activation.

BACKGROUND/AIM: A deep ultraviolet (DUV) light-emitting diode (LED) is a device that can irradiate electromagnetic waves from 250 nm to 350 nm. Tousled-like kinase 1 (TLK1) encodes a nuclear serine/threonine kinase, which is thought to influence the effects of DUV irradiation in cancer. The aim of this study was to clarify the interaction of TLK1 with DUV irradiation-induced DNA damage in cancer cells. MATERIALS AND METHODS: Pancreatic cancer cell lines were treated with or without DUV. TLK1 expression and phosphorylation in the two groups were examined. Then, these cancer cell lines were treated with thioridazine (THD), DUV or both. Thereafter, cytomorphology and apoptosis were assessed. Several proteins related to DNA damage, were analyzed in cancer cells treated with DUV and THD. Tumors in a subcutaneous xenograft model were treated with THD, DUV, or both for six weeks. RESULTS: DUV irradiation induced the phosphorylation of TLK1 in pancreatic cancer cell lines. Cytomorphology was significantly changed in pancreatic cancer cells treated with DUV and THD. TLK1 inhibition enhanced DUV irradiation-induced apoptosis in cancer cells. Interestingly, CHK1 and pCHK1 expression was suppressed after TLK1 inhibition. In addition, inhibition of MRE11 led to a decrease in the expression of CHK1 and pCHK1, accompanied by a notable increase in apoptosis. In the subcutaneous xenograft models, the tumor volume in the DUV and THD groups was lower than that in the other groups. CONCLUSION: TLK1 phosphorylation is an important event in DUV irradiation. DUV irradiation combined with TLK1 inhibition has therapeutic potential in pancreatic cancer cells.