Concomitant Intraductal Papillary Mucinous Neoplasm in Pancreatic Ductal Adenocarcinoma Is an Independent Predictive Factor for the Occurrence of New Cancer in the Remnant Pancreas.

OBJECTIVE: To determine the factors predicting the subsequent development of pancreatic ductal adenocarcinoma in remnant pancreas (PDAC-RP) after partial pancreatectomy for PDAC. SUMMARY BACKGROUND DATA: PDAC-RP after partial pancreatectomy for PDAC is currently not so rare because of improved prognosis of PDAC patients due to recent advances in surgical techniques and adjuvant therapy. However, the predictive factors related to PDAC-RP remain unknown. METHODS: We retrospectively reviewed the clinicopathological data of a consecutive series of 379 patients with PDAC treated by partial pancreatectomy between 1992 and 2015; 14 patients (3.69%) had PDAC-RP. Clinicopathological variables were compared between PDAC-RP and non-PDAC-RP. RESULTS: In univariate analysis, concomitant intraductal papillary mucinous neoplasm (IPMN) (P = 0.0005), cancer location (body/tail) (P = 0.0060), and lower T factor in UICC (P = 0.0039) were correlated with PDAC-RP development. Multivariate analysis revealed concomitant IPMN (P = 0.0135) to be an independent predictive factor for PDAC-RP. PDAC concomitant with IPMN had higher cumulative incidence of PDAC-RP (47.5%/10 yrs) than PDAC without IPMN (9.96%/10 yrs) (P = 0.0071). Moreover, the density of pancreatic intraepithelial neoplasia lesions in the background pancreas of cases of PDAC concomitant with IPMN (1.86/cm) was higher than that of cases of PDAC without IPMN (0.91/cm) (P = 0.0007). CONCLUSIONS: Concomitant IPMN in PDAC is an independent predictive factor for the development of new PDAC in remnant pancreas. Cancer susceptibility of remnant pancreas after resection for PDAC concomitant with IPMN is probably due to an increased density of pancreatic intraepithelial neoplasia lesions.

'Microcystic pattern' should be recognised as part of the morphological spectrum of solid-pseudopapillary neoplasm of the pancreas.

AIM: Solid pseudopapillary neoplasm (SPN) is an uncommon pancreatic tumour characterised by solid and pseudopapillary growth patterns. We have observed SPNs can show a microcystic pattern (microcystic SPN), which has been poorly described and may be confused with microcystic neoplasms. We conducted the present study to clarify the clinicopathological and immunohistochemical features of microcystic SPNs. METHODS AND RESULTS: We examined a consecutive series of 44 SPNs and 10 serous cystadenomas (SCAs), and classified them into 13 microcystic SPNs (29.5%) and 31 conventional SPNs (70.5%). Clinicopathological analysis, immunohistochemical staining and mucin histochemistry were performed. Clear cell change, hyalinised stroma and haemorrhage were observed significantly more frequently in the microcystic SPNs compared to the conventional SPNs. Immunohistochemically, the microcystic SPNs showed significantly lower frequencies of CD10 (0%) and CD56 expression (62%) compared to the conventional SPNs (87%; P < 0.001, 90%; P < 0.0085, respectively). There were no significant differences in other clinicopathological and immunohistochemical features between the two groups (i.e. the nuclear expression of ß-catenin, E-cadherin, progesterone receptor (PgR), lack of forkhead box (Fox)L2 and occasional oestrogen receptor (ER), AE1/AE3 expression). Microcystic SCAs lack such a characteristic immunophenotype. The myxoid stroma of microcystic SPNs contained hyaluronan revealed by Alcian blue stain with hyaluronidase digestion. CONCLUSION: We thus conclude that the microcystic pattern should be recognised as a part of the morphological spectrum of SPNs. Our findings may contribute to the correct diagnosis of the pancreatic neoplasms with the microcystic pattern. In addition, we speculate that stromal change caused by an accumulation of hyaluronan may contribute to the microcystic pattern of SPN.

Brain-derived neurotrophic factor/tropomyosin-related kinase B signaling pathway contributes to the aggressive behavior of lung squamous cell carcinoma.

The tropomyosin-related kinase (Trk) family consists of TrkA, TrkB, and TrkC, which play essential roles in tumor progression and/or suppression in various cancers. Little is known about the biological significance of the Trk family in human lung squamous cell carcinoma (SCC). Here we investigated the clinical significance of the protein expression of Trk family members in samples from 99 SCC patients, and we explored the relationship between invasion/proliferation activities and Trk expression using lung SCC cell lines to clarify the biological significance of the Trk family in lung SCC. Immunohistochemical high expression of TrkB was significantly correlated with vascular invasion (P=0.004), lymph node metastasis (P<0.001), and advanced stage (P=0.0015). The overall survival of the patients with TrkB-high expression was significantly shorter than those with TrkB-low expression (P=0.0110). TrkA/TrkC expressions were not predictors of poor prognosis. An in vitro assay demonstrated that the inhibition of brain-derived neurotrophic factor (BDNF) (a TrkB ligand) and TrkB by K252a (a Trk inhibitor) or siRNA (BDNF-siRNA, TrkB-siRNA) suppressed the invasion, migration, and proliferative activities of lung SCC cells. The administration of recombinant human BDNF (rhBDNF) enhanced the invasion, migration, and proliferation activities, which were abrogated by K252a. TrkB-siRNA transfection increased the protein expression of E-cadherin and decreased vimentin expressions in lung SCC cells. Matrix metalloproteinase-2 (MMP-2)-mediated gelatin degradations were decreased in lung SCC cells transfected with TrkB-siRNA. Thus, TrkB-high expression is an indicator of poor prognosis in lung SCC, probably due to invasion/proliferation activities promoted by the BDNF/TrkB signaling pathway, which could become a therapeutic target for lung SCC.

Molecular Characteristics of Pancreatic Ductal Adenocarcinomas with High-Grade Pancreatic Intraepithelial Neoplasia (PanIN) Are Different from Those without High-Grade PanIN.

AIMS: We reported that pancreatic ductal adenocarcinomas (PDACs) without high-grade pancreatic intraepithelial neoplasia (PanIN) in the vicinity had worse prognoses than PDACs with high-grade PanIN. However, the molecular characteristics of PDACs with and without high-grade PanIN have not been compared. The aim of this study is to clarify the molecular characteristics of PDACs with and without high-grade PanIN. METHOD AND RESULTS: We reviewed all of a consecutive series of 100 patients with PDACs and divided them into 2 groups: the PDACs with PanIN-2 or PanIN-3 in the background (the PanIN-high group, n = 60) and the PDACs without PanIN-2 or PanIN-3 in the background (the PanIN-low group, n = 40). We evaluated the p53, p16, and SMAD4 expressions in the invasive ductal carcinoma (IDC) components by immunohistochemical staining. KRAS mutation was also analyzed in 80 tumors. The PanIN-low group showed significantly more frequent "high p53 expression" and "loss of SMAD4 expression" than the PanIN-high group (p = 0.048 and p = 0.019, respectively). Loss of p16 expression was not significantly different between the groups. The rate of KRAS wild type was significantly higher in the PanIN-low group than the PanIN-high group (p = 0.024). CONCLUSIONS: Our results demonstrated that the molecular characteristics in the PDACs with high-grade PanIN were different from those in the PDACs without high-grade PanIN. PDACs without high-grade PanIN may develop via a pathway other than the PanIN-carcinoma sequence.

Severe hemothorax due to traumatic fracture of thoracic vertebra.

BACKGROUND: Hemothorax occurs in approx. 0.4% of all chest injury patients, but hemothorax due to a thoracic vertebral fracture is rare. CASE PRESENTATION: A 76-year-old Japanese man was transported to our hospital for right hemothorax due to a car accident. We performed emergency hemostasis surgery and tried to stop the bleeding by several methods, but it was difficult to control the bleeding because the bleeding point was an artery branch that runs in front of the vertebral body. CONCLUSION: It is important to be aware that a fractured vertebra can damage the aorta's arterial branch and follow a severe course.

PTPN3 inhibition contributes to the activation of the dendritic cell function to be a promising new immunotherapy target.

PURPOSE: In a previous study, protein tyrosine phosphatase non-receptor type (PTPN) 3 was identified as an immune checkpoint molecule in lymphocytes, and its potential as a novel target for cancer immunotherapy was anticipated. However, evaluation of dendritic cell (DC) function as antigen-presenting cells is critical for the development of immunotherapy. In this study, we aimed to analyze the biological effect of PTPN3 on DCs induced from human peripheral blood monocytes obtained from healthy individuals. METHODS: We used short-interfering RNA to knock down PTP3 in DCs. For DC maturation, we added cancer cell lysate and tumor necrosis factor-α/interferon-α to immature DCs. In the cytotoxic assay, the target cancer cells were SBC5, unmatched with DCs from healthy human leukocyte antigen (HLA)-A24, or Sq-1, matched with DCs. Enzyme-linked immunosorbent assay was used to determine the amount of cytokines. To examine the intracellular signaling system, intracellular staining was used. RESULTS: PTPN3 knockdown significantly increased the number of DCs, expression of CD80 and chemokine receptor (CCR)7, and production of interleukin-12p40/p70 in mature DCs. In the HLA-A24-restricted DC and human lung squamous cell carcinoma cell cytotoxic assay, inhibition of PTPN3 expression in mature DCs induced cytotoxic T lymphocytes with increased production of INF-γ and granzyme B, and enhanced toxicity against cancer cells and migration to cancer. Furthermore, inhibition of PTPN3 expression activated the mitogen-activated protein kinase pathway in DCs. CONCLUSION: Based on our findings, inhibition of PTPN3 expression could contribute to the development of novel cancer immunotherapies that activate not only lymphocytes but also DCs.

Single-incision laparoscopic cholecystectomy with needle graspers.

BACKGROUND/AIMS: Single-incision laparoscopic cholecystectomy (SILC) is a promising alternative to standard multi-incision laparoscopic cholecystectomy (LC). However, generalization of SILC is still hampered by technical difficulties mainly associated with the lack of trocars used for retraction of the gallbladder. We therefore developed a modified method of SILC with the use of needle graspers (SILC-N) for optimal retraction and exposure. METHODOLOGY: In addition to two trocars inserted through a single transumbilical incision, two needle ports were placed on the right subcostal and lateral abdominal wall, through which needle graspers were used for retraction of the gallbladder. Since December, 2009, 12 patients with symptomatic cholelithiasis were treated by SILC-N. RESULTS: SILC-N was successfully performed in all but one patient requiring a conversion to the 4-port LC with a mean operative time of 71.5 (48-107) minutes. None of the patients experienced intraoperative or postoperative complications. The transumbilical incision and pinholes for needle graspers were almost invisible on discharge. CONCLUSIONS: Our preliminary results suggest that SILC-N is a simple, safe and feasible technique of cholecystectomy offering similar postoperative recovery and better cosmetic outcome as compared to conventional LC.

Tropomyosin-related Kinase B Is Potentially a Biomarker of Prognosis and Therapeutic Target for Malignant Thymic Epithelial Tumors.

BACKGROUND/AIM: Thymic epithelial tumors (TETs) mainly consist of thymoma and thymic carcinoma. Complete surgical resection is vital for the successful management of these TETs, and adjuvant therapy such as systematic chemotherapy and/or radiotherapy plays important roles in the management of recurrent or metastasized disease. However, there is still a lack of a standard treatment after the failure of these adjuvant therapies. There is thus a need to develop molecular targeted therapies for advanced malignant TETs. In the present study, we evaluated the biological significance of brain-derived neurotrophic factor (BDNF)/tropomyosin receptor kinase B (TrkB) signaling for TETs. MATERIALS AND METHODS: The expression of TrkB in 48 formalin-fixed, paraffin-embedded TET specimens (43 thymoma and 5 thymic carcinoma) collected by surgical resection was evaluated immunohistochemically. A thymic carcinoma cell line was evaluated for the role of BDNF/TrkB signaling pathway in an in vitro assay. RESULTS: High TrkB expression was related to significantly poor prognosis in patients with TETs. In vitro experiments showed that BDNF/TrkB signaling was involved in the proliferation of Ty-82 cells, but not their invasion and migration. CONCLUSION: TrkB expression is a biomarker of the prognosis for TETs and the BDNF/TrkB signaling pathway is potentially a new therapeutic target for mTETs.

Cancer therapy that targets the Hedgehog signaling pathway considering the cancer microenvironment (Review).

Recently, the cancer microenvironment (CME) has received significant attention. At the local site of the tumor, cancer progression is affected by secreted cytokines and conditions derived from the CME and stimulation by cancer­induced cytokines in an autocrine manner. The CME is characterized by various types of conditions, such as hypoxia, inflammation stimulation, and angiogenesis, and contains various components, such as reactive oxygen species, cancer­associated fibroblasts, infiltrated immune cells, exosomes, and cancer stem cells (CSCs). These conditions and components complicate the progression of cancer. The Hedgehog (HH) signaling pathway is a morphogenesis signaling pathway that is reactivated in some cancers. In these cancers, reactivated HH signaling is involved in the induction of the malignant phenotype. HH signaling is also activated under hypoxic conditions and is considered to be strongly correlated with the CME, including the induction of cancer fibrosis and maintenance of CSCs. The aim of the present review was to elucidate a cancer therapy that targets HH signaling by considering the CME, particularly focusing on hypoxia.

PTPN3 Could Βe a Therapeutic Target of Pancreatic Cancer.

BACKGROUND/AIM: Recently, protein tyrosine phosphatase non-receptor type 3 (PTPN3) has gained attention. However, the role of PTPN3 in cancer has not been fully elucidated. In the present study, we analyzed the role of PTPN3 in pancreatic cancer and investigated whether PTPN3 could be a new therapeutic target for pancreatic cancer. MATERIALS AND METHODS: Two pancreatic ductal adenocarcinoma (PDAC) cell lines were used as target cells. Cell proliferation was investigated using cell counting and a xenograft mouse model. Migration and invasion were analyzed using Transwell inserts. Activation-related signaling molecules were examined by western blotting. RESULTS: PTPN3 contributes to the proliferation, migration, and invasion of PDAC cells in vitro. PTPN3 promotes tumor growth in a mouse xenograft model, an action mediated partially through the MAPK pathway. CONCLUSION: PTPN3 could be a new therapeutic target for pancreatic cancer.

The Novel Selective Pan-TRK Inhibitor ONO-7579 Exhibits Antitumor Efficacy Against Human Gallbladder Cancer In Vitro.

We previously reported that brain-derived neurotrophic factor (BDNF)/neurotrophic receptor tyrosine kinase 2 (NTRK2/TRKB) signaling contributes to induction of malignant phenotype of gallbladder cancer (GBC). Recently, pan-TRK inhibitors have been evaluated and their dramatic clinical activity is being shown for a variety of cancer types harboring an NTRK rearrangement in phase I trials. ONO-7579 is an oral pan-TRK inhibitor currently under investigation in phase I/II clinical trial for TRK-rearranged solid tumors. In this study, we evaluated the anticancer effect of ONO-7579 using GBC cells with or without KRAS mutant, NOZ, TYGBK-1. Our study showed that ONO-7579 had a suppressive effect on GBC proliferation in TYGBK-1, and on invasive potential and vascular endothelial growth factor expression in TYGBK-1 and NOZ. Our data indicated that ONO-7579 could be a promising treatment option for patients with GBC.

Neuroendocrine tumor of the pancreas with rhabdoid feature.

Imaging of a 53-year-old Japanese man revealed two tumors in the liver and a tumor in the head of the pancreas with a swelling lymph node. A needle biopsy for the liver tumors was performed, revealing a neuroendocrine tumor. Enucleation, lymphadenectomy, and partial hepatectomy were performed. The microscopic examination identified many tumor cells with intracytoplasmic inclusions arranged in a nested, cord, or tubular fashion. The intracytoplasmic inclusions displayed densely eosinophilic globules and displaced the nuclei toward the periphery, which constitutes "rhabdoid" features. The tumor cells were positive for synaptophysin and weakly positive for NCAM, but negative for chromogranin A. Epithelial markers (AE1/AE3 and CAM5.2) accentuated intracytoplasmic globules. Pancreatic neuroendocrine tumors with rhabdoid features are very rare. Generally, rhabdoid features are aggressive and dedifferentiated characteristics of various types of tumor. Pancreatic neuroendocrine tumors containing rhabdoid cells tend to display extrapancreatic spread at the time of presentation, although some of these tumors with rhabdoid features are not always associated with aggressive behavior.

Tropomyosin-related kinase B mediated signaling contributes to the induction of malignant phenotype of gallbladder cancer.

This study aims to demonstrate the clinical and biological significance of Brain derived neurotrophic factor (BDNF)/Tropomyosin-related kinase B (TrkB) signaling in gallbladder cancer (GBC) through a series of in vitro and in vivo experiments. TrkB expression was detected in 63 (91.3%) out of 69 surgically resected primary GBC specimens by immunohistochemistry. TrkB expression in the invasive front correlated with T factor (p=0.0391) and clinical staging (p=0.0391). Overall survival was lower in patients with high TrkB expression in the invasive front than in those with low TrkB expression (p=0.0363). In vitro experiment, we used five TrkB-expressing GBC cell lines with or without K-ras mutation. TrkB-mediated signaling increased proliferation and the invasiveness by inducing epithelial mesenchymal transition, and activating matrix metalloproteinases-2 (MMP-2) and MMP-9. Inhibition of TrkB-mediated signaling also decreased hypoxia-inducible factor-1α, vascular endothelial growth factor A (VEGF-A), VEGF-C, and VEGF-D expression. In vivo experiment, inhibition of TrkB-mediated signaling suppressed tumorigenicity and tumor growth in GBC. These findings demonstrate that TrkB-mediated signaling contributes to the induction of malignant phenotypes (proliferation, invasiveness, angiogenesis, lymphangiogenesis, and tumorigenesis) in GBC, and could be a promising therapeutic target regardless of K-ras mutation status.

Intraluminal superior vena cava metastasis from adenosquamous carcinoma of the duodenum: A case report.

In 2013, a 76-year-old male with a cardiac pacemaker was diagnosed with adenosquamous carcinoma of the duodenum. Subsequently, a pancreatoduodenectomy and lymph node dissection were performed, and 12 cycles of adjuvant chemotherapy (modified FOLFOX6 regimen), which consisted of fluorouracil, leucovorin and oxaliplatin, were administered via a central venous catheter. At 5 months after the completion of adjuvant chemotherapy, the patient experienced the sudden onset of severe pain at the back right of the ear, edema of the right side of the face and right jugular vein dilatation. Computed tomography (CT) revealed filling defects in the superior vena cava (SVC) and right brachiocephalic vein, indicating catheter-induced venous thrombosis. Although the catheter was removed and anti-coagulation therapy, aspiration of the thrombosis and ballooning dilatation were performed immediately, the patient's symptoms were not ameliorated. Notably, histological examination following thrombus aspiration revealed metastatic cancer cells, and fluorodeoxyglucose-positron emission tomography/CT identified metabolically active nodules in the SVC at locations consistent with the initial duodenal tumors detected by CT and in the first thoracic vertebrae. The tumor thrombus rapidly increased in size and resulted in worsening dyspnea. Subsequently, radiotherapy was performed, followed by chemotherapy, which relieved the systemic symptoms and suppressed the tumor growth. Adenosquamous carcinoma of the duodenum is extremely rare, and to the best of our knowledge, intraluminal SVC metastasis as a result of adenosquamous carcinoma of the duodenum has not been reported previously. The placement of a cardiac pacemaker, central venous catheter and tumor cells possessing high metastatic potential are hypothesized to have contributed to this rare case of metastasis.