Juan Pablo Arnoletti

ErbB3 expression promotes tumorigenesis in pancreatic adenocarcinoma

Historically, ErbB3 has been overlooked within the ErbB receptor family due to its perceived lack of tyrosine kinase activity. We have previously demonstrated that in pancreatic cancer ErbB3 is the preferred dimerization partner of EGFR, ErbB3 protein expression level directly correlates with the anti-proliferative effect of erlotinib (an EGFR-specific tyrosine kinase inhibitor), and transient knockdown of ErbB3 expression results in acquired resistance to EGFR-targeted therapy. In this study, we develop a stable isogenic model of ErbB3 expression in an attempt to decipher ErbB3s true contribution to pancreatic cancer tumorigenesis and to examine how this receptor affects cellular sensitivity to EGFR-targeted therapy. Analysis of the EGFR-ErbB3 heterodimer demonstrates that ligand-induced PI3K-AKT signaling is limited to ErbB3-expressing cells and that this signaling cascade can be partially abrogated by inhibiting EGFR function with erlotinib. Using our model of exogenous ErbB3 expression we showed a direct relationship between ErbB3 protein levels and increased pancreatic cancer cell proliferation in vitro. In vivo, ErbB3+PANC-1 xenografts had a significantly larger tumor volume than PANC-1 control xenografts (ErbB3-PANC-1) and displayed increased sensitivity to EGFR-targeted therapy. In pancreatic cancer, ErbB3 appears to be critically involved in EGFR signaling as evidenced by its profound effect on cellular proliferation and its ability to influence response to EGFR-targeted therapy.

Endoscopic ultrasound evaluation in the surgical treatment of duodenal and peri-ampullary adenomas

AIM To investigate endoscopic ultrasound (EUS) for predicting depth of mucosal invasion and to analyze outcomes following endoscopic and transduodenal resection. METHODS Records of 111 patients seen at our institution from November 1999 to July 2011 with the post-operative pathological diagnosis of benign ampullary and duodenal adenomas were reviewed. Records of patients who underwent preoperative EUS for diagnostic purposes were identified. The accuracy of EUS in predicting the absence of muscular invasion was assessed by comparing EUS reports to the final surgical pathological results. In addition, the incidence of the post-operative complications over a period of 30 d and the subsequent long-term outcome (recurrence) over a period of 30 mo associated with endoscopic and transduodenal surgical resection was recorded, compared and analyzed. RESULTS Among 111 patients with benign ampullary and duodenal adenomas, 47 underwent preoperative EUS for 29 peri-ampullary lesions and 18 duodenal lesions. In addition, computed tomography was performed in 18 patients, endoscopic retrograde cholangio-pancreatography in 10 patients and esophagogastroduodenoscopy in 22 patients. There were 43 patients with sporadic adenomas and 4 patients with familial adenomatous polyposis (FAP)/other polyposis syndromes. In 38 (81%, P < 0.05) patients, EUS reliably identified absence of submucosal and muscularis invasion. In 4 cases, EUS underestimated submucosal invasion that was proven by pathology. In the other 5 patients, EUS predicted muscularis invasion which could not be demonstrated in the resected specimen. EUS predicted tumor muscularis invasion with a specificity of 88% and negative predictive value of 90% (P < 0.05). Types of resection performed included endoscopic resection in 22 cases, partial duodenectomy in 9 cases, transduodenal ampullectomy with sphincteroplasty in 10 cases and pancreaticoduodenectomy in 6 cases. The main post-operative final pathological results included villous adenoma (n = 5), adenoma (n = 8), tubulovillous adenoma (n = 10), tubular adenoma (n = 20) and hyperplastic polyp (n = 2). Among the 47 patients who underwent resection, 8 (17%, 5 of which corresponded to surgical resection) developed post-procedural complications which included retroperitoneal hematoma, intra-abdominal abscess, wound infection, delayed gastric emptying and prolonged ileus. After median follow-up of 20 mo there were 6 local recurrences (13%, median follow-up = 20 mo) 4 of which were in patients with FAP. CONCLUSION EUS accurately predicts the depth of mucosal invasion in suspected benign ampullary and duodenal adenomas. These patients can safely undergo endoscopic or local resection.

Tamoxifen enhances therapeutic effects of gemcitabine on cholangiocarcinoma tumorigenesis

Cholangiocarcinoma is a highly malignant tumor with limited therapeutic options. We have previously reported that tamoxifen (TMX) induces apoptosis of cholangiocarcinoma cells and reduces cholangiocarcinoma tumorigenesis in mice. In the present studies, we determined the effect of combination therapy of TMX and gemcitabine (GMT), another chemotherapeutical reagent for many cancers, on cholangiocarcinoma tumorigenesis and investigated the responsible mechanisms. GMT inhibited cell growth and induced apoptosis of cholangiocarcinoma cells in a concentration-dependent manner. TMX enhanced GMT-induced apoptosis of cholangiocarcinoma cells. Consistently, GMT (15 mg/kg) inhibited cholangiocarcinoma tumorigenesis in nude mice by 50%. TMX (15 mg/kg) enhanced the inhibitory effect of GMT on tumorigenesis by 33%. The inhibition of tumor growth correlated with enhanced apoptosis in tumor tissues. To elucidate the mechanisms underlying the additive effects of TMX on GMT-induced apoptosis, we determined the activation of caspases in cholangiocarcinoma cells exposed to GMT, TMX, or both. Activation of caspases 9 and 3, as well as cytochrome c release to the cytosol, was demonstrated in cells exposed to both reagents. In contrast, TMX activated caspase 2, whereas GMT had no effect. Inhibition of caspase 2 activation decreased TMX-, but not GMT-, induced activation of caspase 3 and apoptosis of cholangiocarcinoma cells. Similarly, activation of caspase 2 was found in tumors from TMX-treated mice, but not GMT-treated mice. Therefore, the enhanced effect of TMX on GMT-induced cholangiocarcinoma cell death is partially mediated by activation of caspase 2. TMX and GMT both induce apoptosis and inhibit cholangiocarcinoma tumorigenesis, which may be attributed to the activation of distinct apoptosis signals by TMX and GMT. Our studies provide in vivo evidence and molecular insight to support the use of TMX and GMT in combination as an effective therapy for cholangiocarcinoma.

Hairy cell leukemia: A diagnosis by endoscopic ultrasound guided fine needle aspiration

Background Endosonography (EUS) guided FNA is a relatively new imaging modality which is increasingly used for sampling deep-seated lymph nodes in the diagnosis and staging of various malignancies, both primary as well as metastatic. It is also useful for staging of non-Hodgkins lymphoma as well as diagnosing recurrence. The diagnosis of leukemia on FNA samples from deep-seated lymphadenopathy poses an even greater challenge. Hairy cell leukemia (HCL) is an uncommon, but distinct, lympho-proliferative disorder of B cell origin. It usually affects the spleen and bone marrow and uncommonly involves lymph nodes. There are only a few cases reported where HCL was diagnosed on FNA specimens. Case presentation We report the first case of HCL accurately rendered on EUS-FNA samples. Conclusion This report underscores the concept that the presence of a cytopathologist in the endoscopy suite plays an important role in providing accurate diagnoses of lymphoid lesions biopsied with EUS-FNA.

Laparoscopic assistance for endoscopic resection of early stage esophageal cancer (with video).

There are several reports in the literature on the role of laparoscopy-assisted endoscopy and ERCP for management of specific clinical conditions. In this report, we present a high-risk surgical patient with T1 esophageal adenocarcinoma who was managed by endoscopic resection with laparoscopic assistance. The patient had a good clinical outcome, with neither procedure-related complications nor endoscopic evidence of tumor recurrence at mediumterm follow-up.

Fine needle aspiration of an axillary lymph node in a patient suspected of having metastatic cancer of unknown primary

Extramedullary haemopoiesis (EMH) is the production of myeloid, erythroid and megakaryocytic elements at sites other than the bone marrow. 1,2 Clinically, it can present as a solid mass, and therefore malignant neoplasms or metastatic disease must be considered in the differential diagnosis. It most commonly occurs in the liver, spleen and lymph nodes; however a variety of other sites can be involved. EMH normally occurs as a result of a disturbance in bone marrow haematopoiesis or in cases of haemolytic anaemia. EMH is most commonly associated with congenital haemolytic anaemias, but can be seen in conditions such as leukaemia, myeloproliferative disorders and myelofibrosis. A rare cause of EMH is polycythaemia vera (PV). Fine needle aspiration (FNA) is a safe, relatively non-invasive technique often used to diagnose neoplasms and inflammatory diseases. The cytological appearance of EMH obtained via FNA has been reported in the literature. However, the cytological diagnosis of acute leukaemia/chloroma in the background of EMH in a patient with polycythaemia vera by FNA is highly uncommon. We report a case of axillary lymph node EMH diagnosed by FNA, occurring in a patient with PV. Interestingly, due to the presence of increased immature-appearing cells on FNA, the possibility of acute leukaemia/chloroma was raised.

Mucinous Cystic Neoplasm of the Pancreas

A healthy 31-year-old female presented with a 1-year history of microcytic anemia, which was associated ith abdominal pain and a 10-pound weight loss. On physical xamination, there was a palpable tender mass in the left upper uadrant of the abdomen. Previous investigations with an sophagogastroduodenoscopy and capsule endoscopy were esentially normal. However, an ultrasound of the abdomen reealed a complex multiseptated cystic mass measuring 16.5 11.5 cm within the pancreatic tail, as well as splenomegaly. ubsequent computed tomography scan of the abdomen conrmed the presence of the multiseptated lesion and it appeared o be closely associated with both the stomach and the body nd tail of the pancreas. Figure A shows a CT coronal image of the dumbbell-shaped multiseptated pancreatic mass, and an axial image is shown in Figure B. Further imaging with endoscopic ultrasound (EUS) revealed a multiseptated, predominantly cystic extrinsic mass, which appeared to be originating from the distal pancreas and also invading the stomach. Its ultasonographic features were consistent with a cystadenoma (Figure C) and scant mucin was visible on EUS-guided fineneedle aspiration. Serum tumor markers including carcinoembryonic antigen, carbohydrate antigen (CA) 19-9 and CA 125 were all within normal limits. During surgical exploration, a 19.5-cm encapsulated multilocular cyst was completely resected via distal pancreatectomy and splenectomy with en bloc subtotal distal gastrectomy, as the lesion was inseparable from the stomach. A gross image of the pancreatic mucinous cystic neoplasm encased in a smooth outer wall is seen in Figure D, and Figure E shows the multilobulated nature of this lesion in a cross-sectional image. This mass was confirmed to be originating from the pancreatic tail, with invasion of the adjacent gastric wall possibly because of prior cyst rupture leading to local inflammation and adhesion. Furthermore, it was occluding the splenic vein, and hence causing extensive venous congestion with resultant splenomegaly. On histology, the pancreatic mucinous cystic neoplasm was composed of glands lined by tall, mucinproducing cells, and ovarian-type stroma was also present without any evidence of invasive carcinoma cells (Figure F; HE original magnification 100). Additionally, the ovarian-type stromal cells

Abstract 4567: Urine biomarkers outperform serum biomarkers in the diagnosis of various human cancers

Proceedings: AACR 101st Annual Meeting 2010‐‐ Apr 17‐21, 2010; Washington, DC Background: The measurement of biomarkers present in the bodily fluids of cancer patients represents an important avenue for the development of minimally invasive tests to predict tumorigenesis, disease recurrence, or treatment response. A great deal of work along these lines has already been devoted to blood, given its systemic exposure and extensive availability through tissue banks. However, blood is a dynamic biofluid with a proteome under continuous metabolic and homeostatic regulation. Alternatively, urine represents a biofluid that is inherently quiescent in that all molecular and proteolytic activity is largely complete upon sampling. Additional characteristics of urine including its high level of temperature stability and low-complexity matrix resulting from renal filtration have led many to propose urine as an alternative or companion to blood for biomarker studies. Methods: We performed an analysis of biomarkers present in the urine and serum of patients diagnosed with ovarian, pancreatic, and breast cancer utilizing multiplexed bead-based immunoassays developed for the Luminex® xMAP® platform. Ovarian and breast cancer patients were compared to matched healthy controls while the pancreatic cancer patients were compared to a group of patients diagnosed with benign pancreatic conditions. Each case/control group was tested for 10-15 biomarkers identified as informative for each cancer type through previous population-based analyses of serum biomarkers. Results: In our analysis, nearly all of the tested biomarkers were detectable in urine and many of the biomarkers exhibited mean relative differences of greater magnitude in urine versus serum. Our multivariate analysis identified several urine multimarker panels capable of discriminating the cancer from the control groups with high sensitivity and specificity. The use of a 4-biomarker panel comprised of 3 urine biomarkers and one serum biomarker resulted in the discrimination of ovarian cancer patients from healthy controls with a sensitivity of 100% at 95% specificity. For the ovarian and pancreatic cancer comparisons, urine/serum multimarker panels outperformed the best serum biomarker panels identified. A urine 5-biomarker panel was identified in the breast cancer comparison that demonstrated a high discriminatory power in both training and validation sample sets. Conclusions: Our results support the use of urine biomarkers as alternatives and/or companions to serum biomarkers for the diagnosis of selected human cancers. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr 4567.