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The proprotein convertase chaperone protein 7B2 is a new immunohistochemistry marker for primary and metastatic neuroendocrine tumors of the pancreas and GI tract
Vol. 9, No. 4 2005
There were 3 females and 1 male with a median age of 27 years (range, 17-42). Dyspeptic symptoms and abdominal palpable mass represented the initial clinical findings. The main localization of the tumor was the pancreatic head (3 of 4 cases). Enucleation was performed in one case, Whipple’s surgery in 2 cases, and distal pancreatectomy in one case. Curative resection was possible in all cases confirmed by free margins. Two cases showed venous invasion histopathologically. Immunohistochemical analysis was done in 3 cases to confirm the diagnosis. In an average of 15-month follow-up, no recurrence has been observed. Our casuistics showed the preference of the tumor to the head of the pancreas, controversial to literature. However, other characteristics were similar to literature reports (clinical, histopathological, immunohistochemical, and therapeutics). In addition, a longer postoperative follow-up will be necessary to affirm about prognosis.
308 COULD GREEN TEA EXTRACT INHIBIT THE TUMOR GROWTH AND INVASIVENESS IN A HAMSTER PANCREATIC CANCER MODEL? Cı´ntia Yoko Morioka, MD, PhD, Seiji Saito, MD, PhD, Andre´ Siqueira Matheus, MD, PhD, Wellington Andraus, MD, Enio Campos Amico, MD, PhD, Thiago Costa Ribeiro, None, Akiharu Watanabe, MD, PhD, Dilson Pereira Filho, MD, Hideki Arai, Morioka´s Center for Integrative Care, Sa˜o Paulo, SP, Brazil; Toyama Medical and Pharmaceutical University, Toyama, Japan Polyphenolic compounds present in tea may reduce the risk of a variety of illnesses, including cancer. Most studies have shown that tea consumption protects against lung, forestomach, esophagus, duodenum, pancreas, liver, breast, colon, and skin cancers induced by chemical carcinogens. Research findings in laboratory animals have shown the chemopreventive potential of tea polyphenols in cancer, the usefulness of tea polyphenols for humans should be evaluated in clinical trials. Inhibitory effect of green tea extract on the process of pancreatic carcinogenesis induced by nitrosamine and on tumor promotion after transplantation of nitrosamine induced pancreatic cancer in Syrian hamsters. However, there have been no reports using tissue culture to study the effectiveness of this therapy in cancer cells. To verify the anti-invasive activity of green tea extract in hamster pancreatic cancer. HaP-T1, a cell culture derived from BHP-induced hamster pancreatic cancer was used. After treatment with green tea extract, cell proliferation was studied by MTT and MTT-Agarose methods. In vitro chemoinvasion assay with the reconstitution of a matrix of basement membrane onto a filter in a Boyden chamber was used. Migrating cells of the lower chamber were studied by MTT assay. Green tea extract inhibited the tumor growth and invasiveness of HaP-T1 in a dose dependent manner. Green tea extract may be a new anticancer strategy for pancreatic cancer because it could not inhibit only the tumor growth and invasiveness. However, further studies in vivo will be necessary.
309 THE PROPROTEIN CONVERTASE CHAPERONE PROTEIN 7B2 IS A NEW IMMUNOHISTOCHEMISTRY MARKER FOR PRIMARY AND METASTATIC NEUROENDOCRINE TUMORS OF THE PANCREAS AND GI TRACT Caroline Rochon, MD, Shuqing Liu, Cassandre Benay, Prosanto Chaudhury, Nabil Seidah, PhD, Peter Metrakos, MD, McGill University, Montreal, PQ, Canada; Clinical Research Institute of Montreal, Montreal, PQ, Canada 7B2 is a 21-kDa protein known as proprotein convertase PC2 chaperone protein. It escorts the PC2 protein through the secretory pathway
Abstracts
617
and prevents its premature activation. Substrtates of PC2 include proinsulin, proglucagon and pro-CCK. We have previously observed that 7B2 mRNA and protein levels are high in functioning neuroendocrine tumors (NET) of the pancreas when compared with 7B2 mRNA and protein levels in nonfunctioning (NF) NET tumors, unaffected pancreas, normal pancreas and normal islet cells. The objective of this study was to determine if 7B2 could be used as a practical diagnostic marker of neuroendocrine tumors via immunohistochemistry. After appropriate patient consent, primary and metastatic neuroendocrine tumor biopsies from the pancreas, the small bowel, the colon and the liver were snap frozen in the operating room at the time of surgery. The biopsies to be studied via immunohistochemistry were covered in OCT before immersion in liquid nitrogen. Serial 4 micron thick cryostat sections of each neuroendocrine tumor were prepared and fixed in acetone on gelatin coated slides. The slides were blocked in PBS 1% donkey serum and incubated with rabbit anti-human 7B2 antibodies overnight followed by incubation with secondary donkey anti-rabbit fluorescent antibody. Sections were analyzed under fluoromicroscopy. A negative control was also prepared for each section by omitting incubation with the primary antibody. The immunohistochemistry revealed strongly positive results for 7B2 in secreting neuroendocrine tumors (glucagonomas, vipomas, insulinomas, and carcinoid tumors) and negative results for nonfunctioning neuroendocrine tumors. These results are in concordance with the intracellular protein profile of neuroendocrine tumors that we previously established. 7B2 is likely to become another immuno-marker for neuroendocrine tumors in addition to neuron-specific enolase and chromogranin A. While its diagnostic potential is becoming very clear, it is still too early to know what the prongostic implications of tumor 7B2 immunohistochemical positivity will be. So far, there is no difference between primary and metastatic tumors but our tissue biopsy pool is still preliminary. Our patient cohort is being followed so that the implications of 7B2 positivity can be assessed.
310 UNDERSTAGING PANCREATIC CANCER: RESULTS OF COMPREHENSIVE PATHOLOGIC ASSESSMENT OF PANCREATICODUODENECTOMY SPECIMENS Aaron R. Sasson, MD, James M. Gulizia, MD, PhD, University of Nebraska, Omaha, NE Optimal management of localized adenocarcinoma of the head of the pancreas is pancreaticoduodenectomy with microscopically negative resection margins (R0). Multiple studies have demonstrated the adverse impact of positive resection margins (R1) on patient outcome. Assessment of surgical margins is often limited to the pancreatic cut surface, common bile duct (CBD) and posterior margin (pancreatic tissue overlying the inferior vena cava). Tumor extension to the superior mesenteric artery (SMA) and portal and superior mesenteric veins (PV/SMV) is often the limiting factor preventing complete surgical extirpation, yet this area is seldom assessed microscopically. The purpose of the study was to evaluate a comprehensive examination protocol of pancreaticoduodenectomy specimens to determine the frequency of microscopically positive SMA and PV/SMV margins, collectively referred to as mesenteric margin. Between 2001 and 2004, 27 patients underwent pancreaticoduodenectomy for pancreatic adenocarcinoma, with removal of all gross tumor (R0, R1). Following resection, the surgeon, in the presence of the pathologist, oriented the specimens and placed marking sutures denoting the following margins: pancreatic cut margin, CBD, posterior margin (pancreatic tissue overlying the inferior vena cava), SMA and PV/SMV. Margins were considered positive if tumor was present within 1 mm of inked surfaces. Of the 27 specimens analyzed, 12 (44%) had microscopically positive resection margins. The frequency of positive margins was: PV/SMV (6), SMA (5), posterior (3), pancreatic (2), and CBD (1).
There were 3 females and 1 male with a median age of 27 years (range, 17-42). Dyspeptic symptoms and abdominal palpable mass represented the initial clinical findings. The main localization of the tumor was the pancreatic head (3 of 4 cases). Enucleation was performed in one case, Whipple’s surgery in 2 cases, and distal pancreatectomy in one case. Curative resection was possible in all cases confirmed by free margins. Two cases showed venous invasion histopathologically. Immunohistochemical analysis was done in 3 cases to confirm the diagnosis. In an average of 15-month follow-up, no recurrence has been observed. Our casuistics showed the preference of the tumor to the head of the pancreas, controversial to literature. However, other characteristics were similar to literature reports (clinical, histopathological, immunohistochemical, and therapeutics). In addition, a longer postoperative follow-up will be necessary to affirm about prognosis.
308 COULD GREEN TEA EXTRACT INHIBIT THE TUMOR GROWTH AND INVASIVENESS IN A HAMSTER PANCREATIC CANCER MODEL? Cı´ntia Yoko Morioka, MD, PhD, Seiji Saito, MD, PhD, Andre´ Siqueira Matheus, MD, PhD, Wellington Andraus, MD, Enio Campos Amico, MD, PhD, Thiago Costa Ribeiro, None, Akiharu Watanabe, MD, PhD, Dilson Pereira Filho, MD, Hideki Arai, Morioka´s Center for Integrative Care, Sa˜o Paulo, SP, Brazil; Toyama Medical and Pharmaceutical University, Toyama, Japan Polyphenolic compounds present in tea may reduce the risk of a variety of illnesses, including cancer. Most studies have shown that tea consumption protects against lung, forestomach, esophagus, duodenum, pancreas, liver, breast, colon, and skin cancers induced by chemical carcinogens. Research findings in laboratory animals have shown the chemopreventive potential of tea polyphenols in cancer, the usefulness of tea polyphenols for humans should be evaluated in clinical trials. Inhibitory effect of green tea extract on the process of pancreatic carcinogenesis induced by nitrosamine and on tumor promotion after transplantation of nitrosamine induced pancreatic cancer in Syrian hamsters. However, there have been no reports using tissue culture to study the effectiveness of this therapy in cancer cells. To verify the anti-invasive activity of green tea extract in hamster pancreatic cancer. HaP-T1, a cell culture derived from BHP-induced hamster pancreatic cancer was used. After treatment with green tea extract, cell proliferation was studied by MTT and MTT-Agarose methods. In vitro chemoinvasion assay with the reconstitution of a matrix of basement membrane onto a filter in a Boyden chamber was used. Migrating cells of the lower chamber were studied by MTT assay. Green tea extract inhibited the tumor growth and invasiveness of HaP-T1 in a dose dependent manner. Green tea extract may be a new anticancer strategy for pancreatic cancer because it could not inhibit only the tumor growth and invasiveness. However, further studies in vivo will be necessary.
309 THE PROPROTEIN CONVERTASE CHAPERONE PROTEIN 7B2 IS A NEW IMMUNOHISTOCHEMISTRY MARKER FOR PRIMARY AND METASTATIC NEUROENDOCRINE TUMORS OF THE PANCREAS AND GI TRACT Caroline Rochon, MD, Shuqing Liu, Cassandre Benay, Prosanto Chaudhury, Nabil Seidah, PhD, Peter Metrakos, MD, McGill University, Montreal, PQ, Canada; Clinical Research Institute of Montreal, Montreal, PQ, Canada 7B2 is a 21-kDa protein known as proprotein convertase PC2 chaperone protein. It escorts the PC2 protein through the secretory pathway
Abstracts
617
and prevents its premature activation. Substrtates of PC2 include proinsulin, proglucagon and pro-CCK. We have previously observed that 7B2 mRNA and protein levels are high in functioning neuroendocrine tumors (NET) of the pancreas when compared with 7B2 mRNA and protein levels in nonfunctioning (NF) NET tumors, unaffected pancreas, normal pancreas and normal islet cells. The objective of this study was to determine if 7B2 could be used as a practical diagnostic marker of neuroendocrine tumors via immunohistochemistry. After appropriate patient consent, primary and metastatic neuroendocrine tumor biopsies from the pancreas, the small bowel, the colon and the liver were snap frozen in the operating room at the time of surgery. The biopsies to be studied via immunohistochemistry were covered in OCT before immersion in liquid nitrogen. Serial 4 micron thick cryostat sections of each neuroendocrine tumor were prepared and fixed in acetone on gelatin coated slides. The slides were blocked in PBS 1% donkey serum and incubated with rabbit anti-human 7B2 antibodies overnight followed by incubation with secondary donkey anti-rabbit fluorescent antibody. Sections were analyzed under fluoromicroscopy. A negative control was also prepared for each section by omitting incubation with the primary antibody. The immunohistochemistry revealed strongly positive results for 7B2 in secreting neuroendocrine tumors (glucagonomas, vipomas, insulinomas, and carcinoid tumors) and negative results for nonfunctioning neuroendocrine tumors. These results are in concordance with the intracellular protein profile of neuroendocrine tumors that we previously established. 7B2 is likely to become another immuno-marker for neuroendocrine tumors in addition to neuron-specific enolase and chromogranin A. While its diagnostic potential is becoming very clear, it is still too early to know what the prongostic implications of tumor 7B2 immunohistochemical positivity will be. So far, there is no difference between primary and metastatic tumors but our tissue biopsy pool is still preliminary. Our patient cohort is being followed so that the implications of 7B2 positivity can be assessed.
310 UNDERSTAGING PANCREATIC CANCER: RESULTS OF COMPREHENSIVE PATHOLOGIC ASSESSMENT OF PANCREATICODUODENECTOMY SPECIMENS Aaron R. Sasson, MD, James M. Gulizia, MD, PhD, University of Nebraska, Omaha, NE Optimal management of localized adenocarcinoma of the head of the pancreas is pancreaticoduodenectomy with microscopically negative resection margins (R0). Multiple studies have demonstrated the adverse impact of positive resection margins (R1) on patient outcome. Assessment of surgical margins is often limited to the pancreatic cut surface, common bile duct (CBD) and posterior margin (pancreatic tissue overlying the inferior vena cava). Tumor extension to the superior mesenteric artery (SMA) and portal and superior mesenteric veins (PV/SMV) is often the limiting factor preventing complete surgical extirpation, yet this area is seldom assessed microscopically. The purpose of the study was to evaluate a comprehensive examination protocol of pancreaticoduodenectomy specimens to determine the frequency of microscopically positive SMA and PV/SMV margins, collectively referred to as mesenteric margin. Between 2001 and 2004, 27 patients underwent pancreaticoduodenectomy for pancreatic adenocarcinoma, with removal of all gross tumor (R0, R1). Following resection, the surgeon, in the presence of the pathologist, oriented the specimens and placed marking sutures denoting the following margins: pancreatic cut margin, CBD, posterior margin (pancreatic tissue overlying the inferior vena cava), SMA and PV/SMV. Margins were considered positive if tumor was present within 1 mm of inked surfaces. Of the 27 specimens analyzed, 12 (44%) had microscopically positive resection margins. The frequency of positive margins was: PV/SMV (6), SMA (5), posterior (3), pancreatic (2), and CBD (1).