The Expression of Programmed Death-Ligand 1 on Immune Cells Is Related to a Better Prognosis in Biliary Tract Cancer

Background/Aims@#Programmed death-ligand 1 (PD-L1) expression in tumor cells is associated with a poor biliary tract cancer (BTC) prognosis; tumor-infiltrating immune cells in the tumor microenvironment are associated with a better prognosis. The effect of PD-L1 expression on immune cells on survival is unclear. We investigated the relationship between PD-L1 expression in immune cells and BTC prognosis. @*Methods@#PD-L1 expression was evaluated using an anti-PD-L1 22C3 mouse monoclonal primary antibody, and its relationships with clinical characteristics and prognosis were analyzed using the Cox proportional hazard model to investigate the prognostic performance of PD-L1 in BTC. @*Results@#Among 144 analyzed cases, patients with positive PD-L1 expression in tumor cells and negative PD-L1 expression in immune cells showed poorer overall survival rates than those exhibiting other expressions (tumor cells: hazard ratio [HR]=1.023, p<0.001; immune cells: HR=0.983, p=0.021). PD-L1 expression in tumor cells was an independent predictor of poor overall survival (HR=1.024, p<0.001). In contrast, PD-L1 expression in immune cells was a predictive marker of good prognosis (HR=0.983, p=0.018). @*Conclusions@#PD-L1 expression in immune cells may be used as an independent factor to evaluate the prognosis of patients with BTC.

Machine-Learning Model for the Prediction of Hypoxaemia during Endoscopic Retrograde Cholangiopancreatography under Monitored Anaesthesia Care

Purpose@#Hypoxaemia is a significant adverse event during endoscopic retrograde cholangiopancreatography (ERCP) under monitored anaesthesia care (MAC); however, no model has been developed to predict hypoxaemia. We aimed to develop and compare logistic regression (LR) and machine learning (ML) models to predict hypoxaemia during ERCP under MAC. @*Materials and Methods@#We collected patient data from our institutional ERCP database. The study population was randomly divided into training and test sets (7:3). Models were fit to training data and evaluated on unseen test data. The training set was further split into k-fold (k=5) for tuning hyperparameters, such as feature selection and early stopping. Models were trained over k loops; the i-th fold was set aside as a validation set in the i-th loop. Model performance was measured using area under the curve (AUC). @*Results@#We identified 6114 cases of ERCP under MAC, with a total hypoxaemia rate of 5.9%. The LR model was established by combining eight variables and had a test AUC of 0.693. The ML and LR models were evaluated on 30 independent data splits. The average test AUC for LR was 0.7230, which improved to 0.7336 by adding eight more variables with an l 1 regularisation-based selection technique and ensembling the LRs and gradient boosting algorithm (GBM). The high-risk group was discriminated using the GBM ensemble model, with a sensitivity and specificity of 63.6% and 72.2%, respectively. @*Conclusion@#We established GBM ensemble model and LR model for risk prediction, which demonstrated good potential for preventing hypoxaemia during ERCP under MAC.

Response to Neoadjuvant Therapy and Prognosis in Patients with Resectable Pancreatic Cancer: A Propensity Score Matching Analysis

Background/Aims@#Controversy regarding the effectiveness of neoadjuvant therapy for resectable pancreatic ductal adenocarcinoma (PDAC) still exists. Here, we aimed to identify the potential benefits of neoadjuvant therapy followed by surgery for resectable PDAC. @*Methods@#We reviewed radiologically resectable PDAC patients who received resection with curative intent at a tertiary hospital in South Korea between January 2012 and August 2019. A total of 202 patients underwent curative resection for resectable PDAC: 167 underwent surgical resection first during this period, and 35 received neoadjuvant chemotherapy/chemoradiation therapy followed by surgery. Resectable PDAC patients were subdivided, and 1:3 propensity score matching (PSM) was performed to reduce selection bias. @*Results@#Compared with the group that received surgery first, the group that received neoadjuvant treatment followed by surgery had significantly smaller tumors (22.0 mm vs 27.0 mm, p=0.004), a smaller proportion of patients with postoperative pathologic T stage (p=0.026), a smaller proportion of patients with lymphovascular invasion (20.0% vs 40.7%, p=0.022), and a larger proportion of patients with negative resection margins (74.3% vs 51.5%, p=0.049). After PSM, the group that received neoadjuvant therapy had a significantly longer progression-free survival than those in the group that underwent surgery first (29.6 months vs 15.1 months, p=0.002). Overall survival was not significantly different between the two groups after PSM analysis. @*Conclusions@#We observed significantly better surgical outcomes and progression-free survival with the addition of neoadjuvant therapy to the management of resectable PDAC. However, despite PSM, there was still selection bias due to the use of different regimens between the groups receiving surgery first and neoadjuvant therapy. Large homogeneous samples are needed in the future prospective studies.

Insulin-Like Growth Factor-1 Receptor Targeted Fluorescent Imaging for Gallbladder Cancer in Orthotopic Mouse Models

Background/Aims@#Gallbladder cancer is fatal, but fluorescent imaging technology can facilitate timely diagnosis and improve patient outcomes. Fluorophore-conjugated insulin-like growth factor-1 receptor (IGF-1R) targeted antibodies were used to visualize gallbladder cancer in orthotopic tumor mouse models. @*Methods@#Western blotting, flow cytometric analysis, and confocal microscopy detected the expression of IGF-1R in SNU-308, SNU-478, and SNU-1196 bile duct cancer cells. In vivo imaging of SNU-478 and SNU-1196 subcutaneous tumors and orthotopic gallbladder tumor models of SNU-478 were performed after injection with DyLight 650-conjugated IGF-1R antibody. @*Results@#Western blotting and flow cytometric analysis showed that IGF-1R was expressed in bile duct cancer cells, and confocal microscopy demonstrated that IGF-1R antibody was able to bind to IGF-1R on the cell membrane. Fluorescent IGF-1R antibody injected into the mouse tail vein made subcutaneous tumors and orthotopic tumors become fluorescent. The intensity of fluorescence from the tumor was stronger than that from surrounding normal tissues. Histochemical examination confirmed that the tumor was located inside the gallbladder and adjacent liver parenchyma of mice. @*Conclusions@#Our study showed that a fluorescent IGF-1R-targeted antibody could help detect gallbladder tumors. Tumor-specific imaging technology can be applied to endoscopy, laparoscopy, and robotic surgery for better management of gallbladder cancer.

Analysis of Clinical Predictive Factors Affecting the Outcome of Second-Line Chemotherapy for Gemcitabine-Refractory Advanced Pancreatic Cancer

Background/Aims@#The benefit of second-line chemotherapy (SL) after failed first-line chemotherapy (FL) in patients with advanced pancreatic cancer has not yet been established. We evaluated the clinical characteristics affecting the benefits of SL compared to best supportive care (BSC), identified the prognostic factors, and ultimately devised a model of clinical parameters to assist in making decision between SL and BSC after the failure of gemcitabine-based FL. @*Methods@#The records of patients who received gemcitabine-based FL for advanced pancreatic cancer at Yonsei University Hospital between January 2010 and December 2015 were retrospectively reviewed. Significant clinical parameters were assessed for their potential as predictive factors. @*Results@#SL patients received a longer duration of FL compared with BSC patients with median duration being 16.0 weeks (range, 8.0 to 26.0 weeks) and 8.0 weeks (range, 4.0 to 16.0 weeks), respectively (p<0.001). When the SL group was stratified by their modified overall survival (mOS) (longer and shorter than 6 months), we found significant differences for several clinical factors, namely, metastasis to the peritoneum (p<0.001), number of metastases (p<0.001), thrombotic events (p=0.003), and level of carbohydrate antigen 19-9 (CA19-9; p=0.011). In multivariate analysis, more than one site of metastasis, occurrence of thrombotic event during FL, and a CA19-9 level above 90 U/mL were significant independent prognostic factors for mOS in the SL group (p<0.05). When an attempt was made to devise a prognostic nomogram, Harrell’s C-index of the final prognosis prediction model was 0.62. @*Conclusions@#SL may be beneficial for patients without peritoneal metastasis or thrombotic events who have a single metastasis and a level of CA19-9 less than 90 U/mL. This prognostic nomogram can be used to predict mOS before the administration of SL after the failure of gemcitabine-based FL.

A Case of 47-Years-Old Female with Obstructive Jaundice and Weight Loss / 대한소화기암학회지

Serine protease inhibitor Kazal-type 1 (SPINK1) is a gene expressed from pancreatic acinar cell which its mutation is known to be associated with chronic pancreatitis (CP) and pancreatic cancer. We report a case of a 47-years-old female with nausea and weight loss with yellow discoloration of skin. Initial imaging and endoscopic study led us to an impression of chronic pancreatitis with pancreatic cancer with common bile-duct dilation. Biopsy result was confirmed with pancreatic adenocarcinoma and additional imaging revealed lymph node and bone metastasis. Our genetic analysis revealed 194+2T>C mutation of SPINK1. Biliary obstruction was successfully decompressed by stent insertion and underwent chemotherapy and radiotherapy. Although there is accumulating evidence of association between SPINK1 mutation and CP, the relationship between SPINK1 mutation and pancreatic cancer in CP patient is an emerging concept. Genetic analysis should be considered in patients with young age especially when diagnosed with both CP and pancreatic cancer.

Irreversible Electroporation in Patients with Pancreatic Cancer :Angel and Devil / 대한소화기암학회지

Pancreatic cancer has a very poor prognosis. Complete surgical resection remains the only current curative treatment. Locally advanced pancreatic cancer (LAPC) is considered as unresectable because of involvement of celiac and/or mesenteric vessels. The treatment of LAPC is a challenge. Current guidelines suggest systemic therapy. However, the majority of patients will never experience conversion to surgical resection. Thus, in these patients, ablation is an alternative therapy for local control, which causes local destruction while ideally avoiding injury to surrounding healthy tissue. Irreversible electroporation (IRE) is an energy delivery system, effective in ablating tumors by inducing irreversible membrane destruction of cells. IRE demonstrated to be safe in previous studies. However, it is not free from complications, even serious. Here, we reported two cases of the IRE in LAPC patients.

Second Primary Cancer after Treating Gastrointestinal Cancer / 대한소화기학회지

Advances in diagnosis and therapeutic technologies have brought increased life expectancy for most cancers, but paradoxically it also has increased the risk of second primary malignancies. Cancer survivors have a higher risk of developing cancer than the general population. This suggests that more studies are needed to develop screen and management programs for cancer survivors, especially patients with gastrointestinal cancers, which are the most common cancers in Korea.

Second Primary Cancer after Treating Gastrointestinal Cancer / 대한소화기병학회잡지

Advances in diagnosis and therapeutic technologies have brought increased life expectancy for most cancers, but paradoxically it also has increased the risk of second primary malignancies. Cancer survivors have a higher risk of developing cancer than the general population. This suggests that more studies are needed to develop screen and management programs for cancer survivors, especially patients with gastrointestinal cancers, which are the most common cancers in Korea.

Bleeding Complications and Clinical Safety of Endoscopic Retrograde Cholangiopancreatography in Patients with Liver Cirrhosis

PURPOSE: Patients with liver cirrhosis are considered to be at risk for additional adverse events during endoscopic retrograde cholangiopancreatography (ERCP). The present study was designed as a propensity-score matched analysis to investigate whether cirrhotic liver increases the risk of bleeding complications in patients undergoing ERCP. MATERIALS AND METHODS: In total, 8554 patients who underwent ERCP from January 2005 to December 2015 were retrospectively analyzed. To adjust for the imbalance between patients with and those without liver cirrhosis, 1:3 propensity score matching was performed according to age and sex. RESULTS: Liver cirrhosis was identified in 264 (3.1%) patients. After propensity score matching, a total of 768 patients were included in each of the cirrhotic (n=192) and non-cirrhotic groups (n=576). Post-procedure bleeding (10.9% vs. 4.7%, p=0.003) was more frequently observed in patients with liver cirrhosis than in those without. In multivariate analyses, liver cirrhosis was identified as an independent risk factor associated with post-ERCP bleeding (p=0.003) after further adjustment for prothrombin time, antiplatelet/coagulant, duration of ERCP, and stent insertion. Child-Pugh (CP) class C was found to be associated with an increased incidence of post-ERCP bleeding in patients with cirrhosis (odds ratio 6.144, 95% confidence interval 1.320–28.606; p=0.021). CONCLUSION: The incidence of post-ERCP bleeding in patients with liver cirrhosis was higher than that in patients without liver cirrhosis. In particular, CP class C cirrhosis was significantly associated with post-ERCP bleeding.

Clinical Value of Contrast-Enhanced Harmonic Endoscopic Ultrasonography in the Differential Diagnosis of Pancreatic and Gallbladder Masses

BACKGROUND/AIMS: Recent studies have revealed that contrast-enhanced harmonic endoscopic ultrasonography (CEH-EUS) is beneficial in the differential diagnosis of malignant neoplasms of the pancreas and gallbladder from benign masses, in terms of the evaluation of microvasculature and real-time perfusion. In this study, we aimed to prove the clinical value of CEH-EUS in the differential diagnosis of pancreatic and gallbladder masses by direct comparison with that of conventional EUS. METHODS: We reviewed the sonographic images and medical information of 471 patients who underwent conventional EUS and CEH-EUS for the diagnosis of pancreatic and gallbladder masses at a single medical center (Severance Hospital, Seoul, Korea) between March 2010 and March 2016. RESULTS: The enhancement pattern of CEH-EUS of the pancreatic solid masses showed higher sensitivity and specificity in differentiating pancreatic adenocarcinoma and neuroendocrine tumors (82.0% and 87.9% for pancreatic adenocarcinoma and 81.1% and 90.9% for neuroendocrine tumors, respectively), and the area under the receiver operating characteristic curves was higher than that of conventional EUS. The enhancement texture of CEH-EUS of the gallbladder masses showed a higher sensitivity in differentiating malignant masses than that of conventional EUS; however, the difference between the areas under the receiver operating characteristic curves was not statistically significant. CONCLUSIONS: CEH-EUS can complement conventional EUS in the diagnosis of pancreatic and gallbladder masses, in terms of the limitations of the latter.

Assessment of the Risk of Colorectal Cancer Survivors Developing a Second Primary Pancreatic Cancer

BACKGROUND/AIMS: We aimed to investigate the incidence of second primary pancreatic cancer (PC) after colorectal cancer (CRC) and to identify risk factors associated with subsequent PC. METHODS: The observed incidence of a subsequent PC in patients with CRC was standardized using a population with CRC from the Korean Central Cancer Registry (KCCR). The expected incidence rate of PC was obtained by assuming that the select group experienced the same cancer incidence as the corresponding general population in the KCCR. RESULTS: The registry included 4,822 patients with CRC aged 45 to 74 years, representing 16,725.1 person-years of follow-up. Thirteen patients (0.3%) were diagnosed with a subsequent PC, and the overall age-adjusted incidence of second primary PC was 269.6 per 100,000 cases. In contrast, the overall incidence of primary PC in the general population was 18.68 per 100,000 individuals. The standardized incidence ratio of subsequent PC was 14.44, which was significantly higher in patients with CRC than in the general population. Sex, diabetes mellitus, smoking, body mass index, and a history of receiving chemotherapy as a treatment for CRC did not increase the risk of subsequent development of PC. CONCLUSIONS: The risk of a second primary PC was higher in patients with CRC. Further studies are needed to identify the risk factors and generate a screening strategy for cancer survivors.

Cholecystectomy for Prevention of Recurrence after Endoscopic Clearance of Bile Duct Stones in Korea

PURPOSE: Cholecystectomy in patients with an intact gallbladder after endoscopic removal of stones from the common bile duct (CBD) remains controversial. We conducted a case-control study to determine the risk of recurrent CBD stones and the benefit of cholecystectomy for prevention of recurrence after endoscopic removal of stones from the CBD in Korean patients. MATERIALS AND METHODS: A total of 317 patients who underwent endoscopic CBD stone extraction between 2006 and 2012 were included. Possible risk factors for the recurrence of CBD stones including previous cholecystectomy history, bile duct diameter, stone size, number of stones, stone composition, and the presence of a periampullary diverticulum were analyzed. RESULTS: The mean duration of follow-up after CBD stone extraction was 25.4+/-22.0 months. A CBD diameter of 15 mm or larger [odds ratio (OR), 1.930; 95% confidence interval (CI), 1.098 to 3.391; p=0.022] and the presence of a periampullary diverticulum (OR, 1.859; 95% CI, 1.014 to 3.408; p=0.045) were independent predictive factors for CBD stone recurrence. Seventeen patients (26.6%) in the recurrence group underwent elective cholecystectomy soon after endoscopic extraction of CBD stones, compared to 88 (34.8%) in the non-recurrence group; the difference was not statistically significant (p=0.212). CONCLUSION: A CBD diameter of 15 mm or larger and the presence of a periampullary diverticulum were found to be potential predictive factors for recurrence after endoscopic extraction of CBD stones. Elective cholecystectomy after clearance of CBD stones did not reduce the incidence of recurrent CBD stones in Korean patients.

Concomitant Statin Use Has a Favorable Effect on Gemcitabine-Erlotinib Combination Chemotherapy for Advanced Pancreatic Cancer

PURPOSE: Erlotinib-gemcitabine combined chemotherapy is considered as the standard treatment for unresectable pancreatic cancer. This study aimed to determine the clinical factors associated with response to this treatment. MATERIALS AND METHODS: This retrospective study included 180 patients with unresectable pancreatic cancer who received ≥2 cycles of gemcitabine-erlotinib combination therapy as first-line palliative chemotherapy between 2006 and 2014. "Long-term response" was defined as tumor stabilization after >6 chemotherapy cycles. RESULTS: The median progression-free survival (PFS) and overall survival (OS) were 3.9 and 8.1 months, respectively. On univariate analysis, liver metastasis (p=0.023) was negatively correlated with long-term response. Locally advanced stage (p=0.017), a history of statin treatment (p=0.01), and carcinoembryonic antigen levels <4.5 (p=0.029) had a favorable effect on long-term response. On multivariate analysis, a history of statin treatment was the only independent favorable factor for long-term response (p=0.017). Prognostic factors for OS and PFS were significantly correlated with liver metastasis (p=0.031 and 0.013, respectively). A history of statin treatment was also significantly associated with OS after adjusting for all potential confounders (hazard ratio, 0.48; 95% confidence interval, 0.26-0.92; p=0.026). CONCLUSION: These results suggest that statins have a favorable effect on "long-term response" to gemcitabine-erlotinib chemotherapy in unresectable pancreatic cancer patients. Statins may have a chemoadjuvant role in stabilizing long-term tumor growth.

A Comparison of Gastrointestinal Toxicities between Intensity-Modulated Radiotherapy and Three-Dimensional Conformal Radiotherapy for Pancreatic Cancer

BACKGROUND/AIMS: Concurrent chemoradiotherapy (CCRT) is considered the treatment option for locally advanced pancreatic cancer, but accompanying gastrointestinal toxicities are the most common complication. With the introduction of three-dimensional conformal radiotherapy (3-D CRT) and intensity-modulated radiotherapy (IMRT), CCRT-related adverse events are expected to diminish. Here, we evaluated the benefits of radiation modalities by comparing gastrointestinal toxicities between 3-D CRT and IMRT. METHODS: Patients who received CCRT between July 2010 and June 2012 in Severance Hospital, Yonsei University College of Medicine, were enrolled prospectively. The patients underwent upper endoscopy before and 1 month after CCRT. RESULTS: A total of 84 patients were enrolled during the study period. The radiotherapy modalities delivered included 3D-CRT (n=40) and IMRT (n=44). The median follow-up period from the start of CCRT was 10.6 months (range, 3.8 to 29.9 months). The symptoms of dyspepsia, nausea/vomiting, and diarrhea did not differ between the groups. Upper endoscopy revealed significantly more gastroduodenal ulcers in the 3-D CRT group (p=0.003). The modality of radiotherapy (3D-CRT; odds ratio [OR], 11.67; p=0.011) and tumor location (body of pancreas; OR, 11.06; p=0.009) were risk factors for gastrointestinal toxicities. CONCLUSIONS: IMRT is associated with significantly fewer gastroduodenal injuries among patients treated with CCRT for pancreatic cancer.

Photodynamic Therapy Followed by Left Hepatectomy Used to Treat an Intraductal Papillary Mucinous Neoplasm of the Bile Duct / 대한내과학회지

Mucin-hypersecreting bile duct tumors, which closely resemble intraductal papillary mucinous neoplasms of the pancreas, are rare, and both the clinical features and management thereof are poorly understood. As the biliary tract and the pancreas share a common origin, the two diseases may exhibit homologous histopathological features. Certain intraductal papillary tumors of the bile duct are associated with production of large amounts of mucin that disturb bile flow and cause severe biliary dilatation, obstructive jaundice, and cholangitis. Herein, we report on a patient with an extensive intraductal papillary mucinous neoplasm of the bile duct, involving both the right and left intrahepatic ducts. The ducts were subjected to photodynamic therapy, followed by left hepatectomy. The surgical specimen revealed an adenocarcinoma with a negative resection margin. Photodynamic therapy of the intrahepatic ducts was well-tolerated in the present case, and may serve as a useful therapeutic option for selected patients with intraductal papillary mucinous neoplasms of the bile duct.

The Efficacy of Endoscopic Palliation of Obstructive Jaundice in Hepatocellular Carcinoma

PURPOSE: Obstructive jaundice in patients with hepatocellular carcinoma (HCC) is uncommon (0.5-13%). Unlike other causes of obstructive jaundice, the role of endoscopic intervention in obstructive jaundice complicated by HCC has not been clearly defined. The aim of this study was to evaluate the clinical characteristics of obstructive jaundice caused by HCC and predictive factors for successful endoscopic intervention. MATERIALS AND METHODS: From 1999 to 2009, 54 patients with HCC who underwent endoscopic intervention to relieve obstructive jaundice were included. We defined endoscopic intervention as a clinical success when the obstructive jaundice was relieved within 4 weeks. RESULTS: Clinical success was achieved in 23 patients (42.6%). Patients in the clinical success group showed better Child-Pugh liver function (C-P grade A or B/C; 17/6 vs. 8/20), lower total bilirubin levels (8.1+/-5.3 mg/dL vs. 23.1+/-10.4 mg/dL) prior to the treatment, and no history of alcohol consumption. The only factor predictive of clinical success by multivariate analysis was low total bilirubin level at the time of endoscopic intervention, regardless of history of alcohol consumption [odds ratio 1.223 (95% confidence interval, 1.071-1.396), p=0.003]. The cut-off value of pre-endoscopic treatment total bilirubin level was 12.8 mg/dL for predicting the clinical prognosis. Median survival after endoscopic intervention in the clinical success group was notably longer than that in the clinical failure group (5.6 months vs. 1.5 months, p< or =0.001). CONCLUSION: Before endoscopic intervention, liver function, especially total bilirubin level, should be checked to achieve the best clinical outcome. Endoscopic intervention can be helpful to relieve jaundice in well selected patients with HCC.

Duodenal adenocarcinoma following a neuroendocrine tumor in the duodenum

Primary duodenal adenocarcinoma is a rare malignant neoplasm accounting for 0.3% of all gastrointestinal tract carcinomas. We herein present one case of duodenal adenocarcinoma after duodenal neuroendocrine carcinoma. Poorly differentiated duodenal neuroendocrine carcinoma with liver metastasis (TxNxM1) was confirmed, and eight cycles of palliative chemotherapy (5-fluorouracil/etoposide/cisplatin) were administered. The patient was then in a clinically complete response status. About 1 year later, newly developed adenocarcinoma was detected at the same site. It was completely surgically resected, and the patient was cured.

Fatal liver injury complicated by percutaneous catheter drainage after distal pancreatosplenectomy in a patient with pancreatic cancer

Postoperative pancreatic fistula (POPF) combined with postoperative fluid collection, bleeding and abscess formation is one of the most critical morbidities after distal pancreatectomy or pancreaticoduodenectomy. Percutaneous catheter drainage has been commonly used for managing for the postoperative management of abnormal fluid collection. Removal of the catheter is rarely associated with occurrence of life-threatening complication such as serious liver damage. Herein, we report a case of unexpected fatal liver injury complicated by percutaneous catheter drainage treatment after distal pancreatosplenectomy in a patient with pancreatic cancer. We suggest that prudent decision for timing of catheter removal and meticulous care during procedure can reduce the possibility of major liver injury in patients with percutaneous transhepatic catheter drainage.

Clinicopathologic Characteristics Associated with Complications and Long-Term Outcomes of Endoscopic Papillectomy for Adenoma

PURPOSE: Endoscopic papillectomy (EP) is currently employed for the treatment of ampullary adenoma. This study aimed to evaluate the clinical, endoscopic, and histologic characteristics related to complications and long-term outcomes of EP. MATERIALS AND METHODS: Thirty-nine patients underwent EP for ampullary adenoma. Patients were grouped according to the occurrence of procedure-related complications: no complication group (n=28) and complication group (n=11). RESULTS: The overall complication rate was 28.2%. The most common complication was EP-related pancreatitis (n=7). Amylase (p=0.006) and lipase levels (p=0.007), 24 hours after EP, were significantly higher in the complication group, however, these levels did not differ at earlier times. As the tumor progressed from adenoma to cancer, the complete resection was significantly lessened (p=0.032). The duration of antiprotease injection during the hospital stay was significantly longer (p=0.017) and the transfusion requirements were significantly higher (p=0.018) in the complication group. During a median follow-up of 15 months, three lesions (10.3%) recurred among patients with complete resection (n=29) and five lesions (12.8%) recurred among enrolled patients. One patient with progressive recurrence from low-grade dysplasia to adenocarcinoma was noted during a follow-up of 22 months. CONCLUSION: If symptoms are present, amylase and lipase levels, 24 hours after EP, could help predict possible EP-related pancreatitis. Histologic diagnosis through resected specimens may result in complete resection. Patients with complications need a longer duration of antiprotease injection during their hospital stay and more transfusions. The recurrence rate was not significantly high in completely resected cases, however, there was a possibility of progressive recurrence.