Kazuya Koizumi

Pancreatic ductal adenocarcinomas in long-term follow-up patients with branch duct intraductal papillary mucinous neoplasms.

Objective: Although branch duct intraductal papillary mucinous neoplasms (BD-IPMNs) are slow-growing tumors with a favorable prognosis, the synchronous occurrence of pancreatic ductal adenocarcinomas (PDAs) in patients with BD-IPMNs has been reported. This study was aimed to elucidate the development of PDAs in long-term follow-up patients with BD-IPMNs. Methods: We investigated 89 BD-IPMN patients who had no mural nodules and followed them up conservatively at least 2 years (median follow-up, 64 months; range, 25-158 months). All subjects underwent examinations by imaging modalities including endoscopic retrograde pancreatography. We calculated the standardized incidence ratio (SIR) from the vital statistics compiled by the Ministry of Health, Labor, and Welfare of Japan. Results: Among the 89 patients, 4 cases of PDAs distant from BD-IPMN were observed in 552 patient-years of follow-up (7.2 per 1000 patient-years). The expected number was 0.25, and the SIR of PDAs was 15.8 (95% confidence interval [CI], 4.3-40.4; P = 0.00014). Subgroup analyses showed that the incidence of PDAs was significantly increased in patients 70 years or older (SIR 16.7; 95% CI, 3.4-48.7; P = 0.0008) and in women (SIR 22.5; 95% CI, 2.7-81.1; P = 0.0037). Conclusions: Patients with BD-IPMNs are at a high risk for PDAs. During the follow-up, careful examination is required to detect the development of PDAs in patients with BD-IPMNs.Abbreviations: IPMN - intraductal papillary mucinous neoplasm, PDA - pancreatic ductal adenocarcinoma, ERCP - endoscopic retrograde cholangiopancreatography, MRCP - magnetic resonance cholangiopancreatography, EUS - endoscopic ultrasonography, CT - computed tomography, SIR - standardized incidence ratio

Incidence of Synchronous and Metachronous Pancreatic Carcinoma in 168 Patients with Branch Duct Intraductal Papillary Mucinous Neoplasm

Background/Aims: Although branch duct intraductal papillary mucinous neoplasms of the pancreas (BD-IPMN) are being diagnosed with increasing frequency, the incidence of concomitant pancreatic carcinoma (PC) is not well known. We investigated the incidence and clinical features of synchronous and metachronous PC in patients with BD-IPMN. Methods: We studied 168 BD-IPMN patients diagnosed by various imaging modalities, including endoscopic retrograde pancreatography, between 1990 and 2008. We reviewed the medical records and clinical features in both patients developing and not developing PC. The diagnosis of PC was histologically verified in all patients. Results: PC was observed in 9 (5.4%) of 168 patients. Five were synchronously detected at the time of BD-IPMN diagnosis, whereas four were metachronously identified during the follow-up period. All PCs occurred in regions separate from the BD-IPMN lesion. All PCs represented histologically invasive ductal adenocarcinomas, whereas the BD-IPMN lesion was diagnosed as adenoma. Patients developing PC were significantly older than patients not developing PC (p = 0.017). The diameters of the BD-IPMN lesions and main pancreatic ducts were significantly smaller in patients developing PC than patients not developing PC (p = 0.013 and p < 0.001, respectively). Conclusions: It was not infrequent for PC to occur in the pancreas with BD-IPMN. Particular attention should therefore be paid to the development of PC, even in low-risk BD-IPMN, as well as to changes in BD-IPMN.

Serine/Threonine Kinase AKT Is Frequently Activated in Human Bile Duct Cancer and Is Associated with Increased Radioresistance

The prognosis for patients with bile duct cancer (BDC) remains poor. Although BDC cells are essentially radioresistant, recent reports have suggested that radiation therapy, in addition to its palliative role in the management of BDC, may improve patient survival. A better understanding of the mechanisms that lead to cellular radioresistance may assist in the development of more effective BDC therapies based on radiotherapy in combination with radiosensitizing agents. The serine/threonine kinase AKT/protein kinase B, a downstream effector of phosphatidylinositol 3′-kinase, is a well-characterized kinase that is known to play a critical role in antiapoptotic signaling pathways. In this investigation, we sought to clarify the role of AKT signaling in the radioresistance in BDC cells. First, to examine whether activated AKT is expressed in BDCs, tumor specimens were obtained from 19 consecutive BDC cases. Immunohistochemical staining using an anti-phosphorylated-AKT antibody showed that phosphorylated (activated) AKT was expressed in cancer cells but not in neighboring normal mucosa in 16 cases (84.2%). Next, to evaluate the role of AKT activation in the regulation of BDC cell radiosensitivity, clonogenic assays were performed using the phosphatidylinositol 3′-kinase inhibitor LY294002 with and without irradiation. LY294002 inhibited AKT activation in BDC cells and, on irradiation, decreased clonogenic survival in a radiation dose-dependent manner. Only a small decrease in cell viability was observed in cells exposed to LY294002. Expression of constitutively active AKT in BDC cells resulted in decreased radiosensitivity, whereas a dominant-negative AKT increased radiosensitivity. Furthermore, constitutively active AKT also inhibited radiation-induced apoptosis. Collectively, these results indicate that activated AKT in BDC cells is associated with radioresistance and suggest that pharmacological or genetic modulation of AKT activity may have important therapeutic implications in BDC patients treated with radiation.

Hedgehog Promotes Neovascularization in Pancreatic Cancers by Regulating Ang-1 and IGF-1 Expression in Bone-Marrow Derived Pro-Angiogenic Cells

Background The hedgehog (Hh) pathway has been implicated in the pathogenesis of cancer including pancreatic ductal adenocarcinoma (PDAC). Recent studies have suggested that the oncogenic function of Hh in PDAC involves signaling in the stromal cells rather than cell autonomous effects on the tumor cells. However, the origin and nature of the stromal cell type(s) that are responsive to Hh signaling remained unknown. Since Hh signaling plays a crucial role during embryonic and postnatal vasculogenesis, we speculated that Hh ligand may act on tumor vasculature specifically focusing on bone marrow (BM)-derived cells. Methodology/Principal Findings Cyclopamine was utilized to inhibit the Hh pathway in human PDAC cell lines and their xenografts. BM transplants, co-culture systems of tumor cells and BM-derived pro-angiogenic cells (BMPCs) were employed to assess the role of tumor-derived Hh in regulating the BM compartment and the contribution of BM-derived cells to angiogenesis in PDAC. Cyclopamine administration attenuated Hh signaling in the stroma rather than in the cancer cells as reflected by decreased expression of full length Gli2 protein and Gli1 mRNA specifically in the compartment. Cyclopamine inhibited the growth of PDAC xenografts in association with regression of the tumor vasculature and reduced homing of BM-derived cells to the tumor. Host-derived Ang-1 and IGF-1 mRNA levels were downregulated by cyclopamine in the tumor xenografts. In vitro co-culture and matrigel plug assays demonstrated that PDAC cell-derived Shh induced Ang-1 and IGF-1 production in BMPCs, resulting in their enhanced migration and capillary morphogenesis activity. Conclusions/Significance We identified the BMPCs as alternative stromal targets of Hh-ligand in PDAC suggesting that the tumor vasculature is an attractive therapeutic target of Hh blockade. Our data is consistent with the emerging concept that BM-derived cells make important contributions to epithelial tumorigenesis.

Close correlation between urinary sodium excretion and response to tolvaptan in liver cirrhosis patients with ascites.

To assess the correlation between response to tolvaptan and treatment‐related factors in liver cirrhosis patients.

A phase I study of oral uracil-tegafur prior to weekly intravenous gemcitabine in patients with advanced pancreatic cancer

Background: Gemcitabine is widely accepted as the first-line agent for advanced pancreatic cancer. The antitumor cell activity of gemcitabine is higher when administered after 5-fluorouracil (5-FU) rather than before 5-FU in an in vitro study. The present study was conducted to define the maximum tolerated dose and dose-limiting toxicity associated with an oral fluoropyrimidine prodrug that combines uracil and tegafur (UFT), given prior to weekly intravenous gemcitabine in patients with advanced pancreatic cancer. Methods: Over a 21-day cycle, gemcitabine was given intravenously over 30 min on days 8 and 15, while UFT was given orally from days 1 to 14. The dose of UFT used was 400 mg per day, given as two doses. The dose of gemcitabine was escalated in a stepwise fashion from 800 (level 1, n = 3) to 900 mg/m2 (level 2, n = 6) and then to 1,000 mg/m2 (level 3, n = 3), such that totally 12 patients received the combination chemotherapy. Results: During the first cycle, grade 3 leukopenia was observed in 2 patients at dose level 1. Only 1 patient treated at dose level 2 experienced dose-limiting toxicity (grade 3 elevated transaminase), including additional patients treated at this dose level. No grade 3/4 toxicities occurred in patients treated at dose level 3. A significant response was observed in 1 out of 12 patients (8.3%). Seven patients (58.3%) had stable disease, while 4 patients (33.3%) showed disease progression. Conclusions: The combination chemotherapy of oral UFT and gemcitabine was convenient, well tolerated and may benefit patients with advanced pancreatic cancer. Doses recommended for further study of this schedule are gemcitabine 1,000 mg/m2 and UFT 400 mg/day.

Multiple Cancers of the Biliary Tract and Pancreatic Duct after Cholecystectomy for Gallbladder Cancer in a Patient with Pancreaticobiliary Maljunction

We herein report the rare case of a 76-year-old woman who underwent cholecystectomy with bile duct resection for advanced gallbladder cancer associated with pancreaticobiliary maljunction (PBM) and subsequently developed multiple cancers of the pancreaticobiliary system (the distal bile duct, intrahepatic duct and pancreatic duct) after the operation. We performed conventional endoscopic retrograde cholangiopancreatography (ERCP) using a side-viewing scope to evaluate the masses in the distal bile duct and the pancreatic duct. We also performed ERCP using double-balloon enteroscopy (DBE) to observe the mass in the intrahepatic duct. It was possible to directly observe the lesion using DBE and to perform a biopsy under visual control. All lesions were correctly diagnosed by the combination of ERCP using different endoscopes. The present case suggests that it is necessary to pay close attention (with regard to carcinogenesis) to the whole pancreaticobiliary system in patients with PBM. In addition, the combination of ERCP using DBE and a side-viewing scope may be useful for making a precise diagnosis in patients with altered biliary anatomy who have multiple cancers of the pancreaticobiliary system.

Efficacy of combination therapy with natriuretic and aquaretic drugs in cirrhotic ascites patients: A randomized study

AIM To assess the effects of a combination therapy with natriuretic and aquaretic drugs in cirrhotic ascites patients. METHODS A two-center, randomized, open-label, prospective study was conducted. Japanese patients who met the criteria were randomized to trial group and the combination diuretic group (received 7.5 mg of tolvaptan) or the conventional diuretic group (received 40 mg of furosemide) for 7 d in addition to the natriuretic drug which was used prior to enrolment in this study. The primary endpoint was the change in body weight from the baseline. Vital signs, fluid intake, and laboratory and urinary data were assessed to determine the pharmacological effects after administration of aquaretic and natriuretic drugs. RESULTS A total of 56 patients were randomized to receive either tolvaptan (n = 28) or furosemide (n = 28). In the combination and conventional diuretic groups, the average decrease in body weight from the baseline was 3.21 ± 3.17 kg (P < 0.0001) and 1.75 ± 2.36 kg (P = 0.0006), respectively, when measured on the final dosing day. Following 1 wk of treatment, a significantly greater reduction in body weight was observed in the combination diuretic group compared to that in the conventional diuretic group (P = 0.0412). CONCLUSION Compared to a conventional diuretic therapy with only a natriuretic drug, a combination diuretic therapy with natriuretic and aquaretic drugs is more effective for patients with cirrhotic ascites.

Condyloma acuminatum of the anal canal, treated with endoscopic submucosal dissection

Condyloma acuminatum (CA) is a common sexually transmitted disease caused by human papilloma virus infection. Not all individuals develop persistent, progressive disease, but careful follow up is required with moderate-to-severe dysplasia to prevent progression to malignancy. Standard therapies include surgical treatments (trans-anal resection and trans-anal endoscopic microsurgery) and immunotherapeutic and topical methods (topical imiquimod); however, local recurrence remains a considerable problem. Here, we report a case with superficial CA of the anal canal, treated with endoscopic submucosal dissection (ESD). A 28-year-old man presented with a chief complaint of hematochezia. Digital exam did not detect a tumor. Screening colonoscopy revealed 10-mm long, whitish condyles extending from the anal canal to the lower rectum. The lesion covered almost the whole circumference, and only a small amount of normal mucosa remained. Magnifying endoscopy with narrow band imaging showed brownish hairpin-shaped, coiled capillaries. Although histopathological diagnosis by biopsy revealed CA, accurate histological differentiation between CA, papilloma, and squamous cell carcinoma can be difficult with a small specimen. Therefore, we performed diagnostic ESD, which provides a complete specimen for precise histopathological evaluation. The pathological diagnosis was CA, with moderate dysplasia (anal intraepithelial neoplasia 2). There was no recurrence at 16 mo after the initial ESD. Compared to surgical treatment, endoscopic diagnosis and resection could be performed simultaneously and the tumor margin observed clearly with a magnifying chromocolonoscopy, resulting in less recurrence. These findings suggest that endoscopic resection may be an alternative method for CA that prevents recurrence.

An improved digital polymerase chain reaction protocol to capture low‐copy KRAS mutations in plasma cell‐free DNA by resolving ‘subsampling’ issues

Genetic alterations responsible for the initiation of cancer may serve as immediate biomarkers for early diagnosis. Plasma levels of cell‐free DNA (cfDNA) in patients with cancer are higher than those in healthy individuals; however, the major technical challenge for the widespread implementation of cfDNA genotyping as a diagnostic tool is the insufficient sensitivity and specificity of detecting early‐stage tumors that shed low amounts of cfDNA. To establish a protocol for ultrasensitive droplet digital polymerase chain reaction (ddPCR) for quantification of low‐frequency alleles within a limited cfDNA pool, two‐step multiplex ddPCR targeting eight clinically relevant mutant KRAS variants was examined. Plasma samples from patients with colorectal (n = 10) and pancreatic cancer (n = 9) were evaluated, and cfDNA from healthy volunteers (n = 50) was utilized to calculate reference intervals. Limited cfDNA yields in patients with resectable colorectal and pancreatic cancers did not meet the requirement for efficient capture and quantification of rate mutant alleles by ddPCR. Eight preamplification cycles followed by a second‐run ddPCR were sufficient to obtain approximately 5000–10 000 amplified copies per ng of cfDNA, resolving the subsampling issue. Furthermore, the signal‐to‐noise ratio for rare mutant alleles against the extensive background presented by the wild‐type allele was significantly enhanced. The cutoff limit of reference intervals for mutant KRAS was determined to be ~ 0.09% based on samples from healthy individuals. The modification introduced in the ddPCR protocol facilitated the quantification of low‐copy alleles carrying driver mutations, such as oncogenic KRAS, in localized and early‐stage cancers using small blood volumes, thus offering a minimally invasive modality for timely diagnosis.