Seong Ho Choi

Background:  Pancreatic ductal adenocarcinoma (PDAC) is the fifth most common cause of death from cancer in Korea. PDAC is difficult to diagnose at an early stage and even more difficult to cure. Thus, there is an urgent need to identify molecular targets for early diagnosis and effective treatment. The objectives of this study were to identify differentially expressed biomarker proteins of PDAC using proteomic analysis, to validate the identified biomarker proteins associated with carcinogenesis using western blot analysis and to evaluate clinical factors influencing expression of candidate biomarker proteins.Methods:  In the present study, we carried out proteomic analysis in 10 pairs of PDAC specimens with matching adjacent normal tissues to clarify the different patterns of protein expression. The proteins were separated by high‐resolution 2‐D polyacrylamide gel electrophoresis (2D PAGE) and the differentially expressed proteins were identified by matrix‐assisted laser desorption/ionization time‐of‐flight mass spectrometry (MALDI‐TOF MS). Differential expression of candidate biomarker proteins associated with carcinogenesis was further validated using western blot analysis. Standard statistical analysis was carried out in an attempt to establish a correlation between clinical variables and expression of candidate biomarker proteins.Results:  Analysis of PDAC and the adjacent normal tissues showed reproducibly similar proteomic patterns for each group. Approximately 700 spots each were seen by silver‐stained gels from both PDAC and normal tissues. Differentially expressed protein spots were gel digested and identified by MALDI‐TOF MS. Twenty‐five proteins were identified, of which five proteins (galectin‐1, enolase‐2, α‐1‐antitrypsin, N‐myc interactor, peroxiredoxin‐4) were previously reported as being differentially expressed either at the mRNA level or protein level in human cancer. The five proteins were selected for candidate biomarker proteins related to carcinogenesis. These proteins were further validated by western blot analysis. Among the candidate biomarker proteins, galectin‐1 expression was highly correlated to histology (P = 0.019), T stage (P = 0.047), N stage (P = 0.033) and American Joint Committee on Cancer stage (P = 0.011).Conclusion:  Differentially expressed 25 proteins in PDAC were identified using proteomic analysis and five proteins related to carcinogenesis were validated by western blot analysis. galectin‐1 expression was highly correlated to tumour histology and stage.

Background and Aim:  Our aim was to evaluate the predictive factors for survival and disease‐free survival of patients with resected intrahepatic cholangiocarcinoma (ICC).Methods:  Between October 1994 and 2005, 97 patients with ICC underwent curative hepatic resection. The tumors in 97 patients were reviewed retrospectively to examine the prognosis of ICC.Results:  The 1‐, 3‐ and 5‐year survival rates were 74.9%, 51.8% and 31.1%, respectively. The 1‐, 3‐ and 5‐year disease‐free survival rates were 21.3%, 6.4% and 2.1%, respectively. Univariate analysis showed that tumor size, tumor number, the gross type, resection margin status, T‐stage and lymph node involvement were significant prognostic factors. Multiple tumors and cancer cells in the resection margin were found in multivariate analysis to be significantly related to the prognosis. In the multivariate analysis disease free survival was poor for the patients with a large tumor, multiple lesions, a high CA 19‐9 level, cancer in the resection margin, advanced T‐stage and lymph node involvement.Conclusions:  The overall 5‐year survival rate of ICC was 31.1%. Multiple intrahepatic lesions were a sign of a poor prognosis for ICC. Better survival could be achieved by curative resection with a tumor‐free margin.

Background: There are scant studies that have analyzed the prognostic factors for malignant nonfunctioning endocrine tumors of the pancreas. We identified the predictive factors associated with long‐term survival after surgical resection for malignant nonfunctioning endocrine tumors.Methods: Among the 25 patients seen at our hospital with a diagnosis of malignant nonfunctioning endocrine tumor, a review was performed on 22 of these patients who were surgically treated at our institution over the last 10 years. The following factors were evaluated for disease‐specific mortality: age, gender, tumor location, tumor size, histological differentiation, status of the resection margin, and status of lymph node involvement.Results: Tumor recurrence was noted in 9 cases (40.9%) among the 22 operated patients. Of the 9 recurrent cases, 7 patients (77.8%) had liver metastases. The median follow‐up period was 24.8 (range: 3.7–121.4) months. The overall actuarial 1‐, 2‐ and 5‐year survival rates were 84.1%, 72.5%, and 52.8%, respectively. The factor shown to have a favorable independent prognostic significance was a negative resection margin (odds ratio = 19.44, 95% confidence interval = 1.22–310.54, P = 0.036).Conclusions: Definitive surgical resection of the primary tumor was a predictor of long‐term survival after surgical resection for malignant nonfunctioning endocrine tumor.

Objectives:  Insulinomas are rare tumours that originate from the islet cells of the pancreas. The aims of this study were to gain an understanding of the clinical features of insulinomas and to establish the diagnostic and therapeutic strategies.Methods:  A review was carried out in 20 patients with insulinoma surgically treated in our institution over the last 10 years. Presenting symptoms, biochemical studies, preoperative and intraoperative localization studies, operative management and complications were analysed.Results:  The male‐to‐female ratio was 8:12, with a mean age of 46.4 years. Each patient suffered from significant neuroglycopenic symptoms, usually manifested by dizziness, sweating, headache and confusion. The preoperative median serum levels of glucose, insulin and C‐peptide at the termination of the fast were 37.5 mg/dL, 23.5 μU/mL, 5.6 ng/mL, respectively. Preoperative tumour localization was achieved by means of ultrasonography (US), computed tomography, selective angiography or intra‐arterial calcium injection with hepatic venous sampling, and sensitivities of these examinations were 81.8, 73.7, 94.1 and 100%, respectively. Intraoperative localization was carried out by a combination of manual palpation and intraoperative US with retrospective sensitivities of 80 and 100%, respectively. Enucleation was carried out in 16 patients and distal pancreatectomy in 4. The mortality and morbidity rates were 0 and 10%, respectively. One patient developed late diabetes mellitus type 1 after distal pancreatectomy.Conclusions:  We conclude that the diagnosis of insulinoma can be made on the basis of the results of a supervised fast, careful palpation with intraoperative US is essential for intraoperative detection of insulinomas and surgical resection is the best choice for treatment of benign insulinomas.

Background: The effect of glutamine (Gln) supplementation in patients undergoing a major operation has not been conclusively established. This study was designed to elucidate the effect of Gln supplementation on the surgical outcome after a pancreaticoduodenectomy (PD) for periampullary tumors.Methods: A prospective, randomized, double‐blind, and controlled clinical trial was undertaken for patients who underwent a classical PD or a pylorus‐preserving PD for periampullary tumors. The Gln and control groups received isonitrogenous amino acid, with a 0.2 g/kg per day Gln regimen administered to the Gln group. The surgical outcome was compared in light of length of postoperative hospital stay, nutritional and chemical profiles, and complication rate between the Gln and control groups.Results: Sixty of the consecutive 143 patients who were admitted to undergo operation for periampullary tumors were enrolled in our study; 32 were in the Gln group and 28 in the control group. The two groups were comparable prior to and during the operation. The median length of the postoperative hospital stay and the postoperative nutritional and chemical profiles were not different between two groups. The overall and PD‐related complication rates of the Gln group (37.5% and 25.0%) and the control group (28.6% and 14.3%) were not statistically different.Conclusions: No significant beneficial effect of Gln supplementation with a low‐dose parenteral regimen was demonstrated on the surgical outcome after a PD for periampullary tumors. Therefore, we should be prudent in using Gln as a routine pharmacologic supplement to the standard nutrition in patients who undergo major operations.