Jang Yong Jeon

Predictable Factors for Lymph Node Metastasis in Early Gastric Cancer—Analysis of Single Institutional Experience

IntroductionPrediction of lymph node metastasis in early gastric cancer (EGC) is very important to decide treatment strategies preoperatively. The aim of this study was to evaluate factors that predict the presence of lymph node metastasis and to indentify the differences between mucosal and submucosal gastric cancers.MethodsA total of 376 patients with EGC who underwent gastrectomy from March 1999 through December 2007 were retrospectively identified. The clinopathological factors and biological markers (p53, Ki67) were analyzed.ResultsThe rate of lymph node metastasis was 9.6% (mucosal cancer 2.8%, submucosal cancer 18.4%). Tumor size, depth of invasion, macroscopic type, and lymphovascular invasion were related to lymph node metastasis in EGC. When the carcinomas were confined to the mucosal layer, tumor size and lymphovascular invasion showed significant correlation with lymph node metastasis. On the other side, macroscopic type and lymphovascular invasion were association with lymph node metastasis in submucosal carcinoma.ConclusionThe risk factors for lymph node metastasis in EGC are quite different depending on depth of tumor invasion. To predict lymph node metastasis in EGC, it is recommended that distinct assessment according to individual situation should be clearly established.

Management of endoscopic retrograde cholangiopancreatography-related perforations

Purpose The purpose of this study is to analyze the treatment strategies of patients with endoscopic retrograde cholangiopancreatography (ERCP)-related perforations. This is a retrospective study. Methods We experienced 13 perforations associated with ERCP. We reviewed the medical recordsand classified ERCP-related perforations according to mechanism of injury in terms of perforating device. Injury by endoscopic tip or insertion tube was classified as type I, injury by cannulation catheter or sphincterotomy knife as type II, and injury by guidewire as type III. Results Of four type I injuries, one case was managed by conservative management after primary closure with a hemoclip during ERCP. The other three patients underwent surgical treatments such as primary closure orpancreatico-duodenectomy. Of five type II injuries, two patients underwent conservative management and the other three cases were managed by surgical treatment such as duodenojejunostomy, duodenal diverticulization and pancreatico-duodenectomy. Of four type III injuries, three patients were managed conservatively and the remaining patient was managed by T-tube choledochostomy. Conclusion Type I injuries require immediate surgical management after EPCP or immediate endoscopic closure during ERCP whenever possible. Type II injuries require surgical or conservative treatment according to intra- and retro-peritoneal dirty fluid collection findings following radiologic evaluation. Type III injuries almost always improve after conservative treatment with endoscopic nasobilliary drainage.

Percutaneous Transhepatic Gallbladder Drainage Changes Emergency Laparoscopic Cholecystectomy to an Elective Operation in Patients with Acute Cholecystitis

Many surgeons have found it difficult to decide whether to apply percutaneous transhepatic gallbladder drainage (PTGBD) in patients with acute cholecystitis that is not responsive to initial medical management (IMMx), because the indications of PTGBD are ambiguous. The aim of this study was to evaluate the appropriate treatment for acute cholecystitis that is not responsive to IMMx. Specifically, we focused on differences in surgical outcomes between elective and emergency laparoscopic surgeries. Between March 2006 and February 2009, 738 patients with acute cholecystitis who had undergone laparoscopic cholecystectomy (LC) at our institution were retrospectively studied. We divided them into 3 groups. Group I included 494 patients who underwent elective LC without pre-operative PTGBD, group II included 97 patients who intended to undergo elective LC after preoperative PTGBD, and group III included 147 patients who underwent emergency LC without preoperative PTGBD. We compared age, sex, symptom duration, body temperature, leukocyte counts, and American Society of Anesthesiologists (ASA) class on admission as clinical characteristics. We compared the time interval from symptom development and admission to surgery, operative time, the conversion rate to open surgery, postoperative complications, the total length of stay, and the postoperative length of stay as perioperative surgical outcomes. For patients with ASA 2 and 3, the conversion rate to open surgery in group II was significantly less than that in group III (P<.05, P<.01, respectively). We recommend PTGBD as the first choice for acute cholecystitis in patients who show no improvement after IMMx, to allow the patient to undergo an elective LC rather than emergency surgery for patients with ASA 2 and 3.

Low frequency of KRAS mutation in pancreatic ductal adenocarcinomas in Korean patients and its prognostic value.

Objectives Low prevalence and prognostic relevance of KRAS mutations in Korean pancreatic ductal adenocarcinomas (PDACs) need to be validated with sensitive detection method. Methods Peptide nucleic acid (PNA)–mediated polymerase chain reaction (PCR) clamping was used to precisely detect KRAS mutation in 72 paraffinized tumor samples and was validated by pancreatic cell lines to compare the efficiency of direct sequencing. Results The PNA-mediated PCR clamping detected mutant allele proportions of as low as 0.5% against a background of wild-type DNA and was 20-fold more sensitive than direct sequencing through the validation of pancreatic cell lines. Peptide nucleic acid–mediated PCR clamping detected KRAS mutations in 47.2% of 72 PDACs. Low tumor cellularity and low PCR amplification efficiency led to be undetected or failed by direct sequencing in pancreatic paraffinized samples. KRAS mutations were an independent worse prognostic factor predicting a reduced progression-free survival rate in the postoperative chemotherapy group. Conclusions Peptide nucleic acid clamp real-time PCR was a sensitive method for detecting KRAS status in paraffinized PDAC samples. We identified a low KRAS mutation rate among the Korean PDAC patients using PNA clamp real-time PCR, potentially implicating epidemiological characteristics. The low KRAS mutation rate and its prognostic role may suggest the further survival benefit in Korean PDAC patients.

Low incidence of KRAS, BRAF, and PIK3CA mutations in adenocarcinomas of the ampulla of Vater and their prognostic value

Ampullary adenocarcinomas (A-ACs) are rare malignancies with considerable importance because of their high curable resection rate and improved survival rate among periampullary cancers. The RAS-RAF-MAPK pathway is involved in the development of A-ACs and is a potential therapeutic target. However, molecular profiles of A-ACs and their prognostic impact are poorly understood. Peptide nucleic acid-mediated polymerase chain reaction clamping and Mutyper were used to detect KRAS, BRAF, and PIK3CA mutations in 62 paraffinized samples of A-ACs. Of 62 A-ACs, 30.6% had KRAS mutations, but no BRAF mutations and low frequency (1.6%) of PIK3CA mutation were detected. KRAS mutation was correlated with poor tumor differentiation and was a predictor of shorter recurrence-free survival period in overall A-ACs, whereas the prognosis according to the histologic subtypes was not affected by KRAS mutation. Lymph node metastasis was an independent prognostic factor of poor overall survival. Intestinal- and pancreatobiliary-type A-ACs had similar prognosis. Intestinal- and pancreatobiliary-type A-ACs had different prognostic factors; tumor differentiation and lymph node metastasis strongly predicted overall survival and recurrence-free survival in pancreatobiliary-type tumors, respectively, whereas no independent prognostic factors were demonstrated for intestinal-type tumors. Low incidence of KRAS mutations and their strong prognostic value in A-ACs may suggest the potential of survival benefit depending on the epidermal growth factor receptor-targeted therapy. Much lower frequencies of BRAF and PIK3CA mutations may suggest that they do not play a major role in the tumorigenesis of A-ACs. Different therapeutic protocols should be considered for treating pancreatobiliary- and intestinal-type A-ACs.

Concurrent MET copy number gain and KRAS mutation is a poor prognostic factor in pancreatobiliary subtype ampullary cancers.

Hepatocyte growth factor (HGF) and MET are candidates of targeted therapies for cancer patients. Although MET and HGF are commonly expressed in biliary tract cancers, their expression and gene copy number status and their association with KRAS mutations have not been investigated in pancreatobiliary-type ampullary adenocarcinomas (A-ACs), one of the aggressive periampullary cancers. MET and HGF expressions and MET copy number status were examined by performing immunohistochemistry (IHC) and silver in situ hybridization (SISH) in 62 surgically resected, paraffin-embedded tumors, respectively. High MET and HGF protein expressions were detected in 24 (38.7%) and 15 (24.2%) tumors. High MET expression was associated with KRAS mutation. However, there were no associations of high MET/HGF expression alone with other clinicopathological feature or survival. MET SISH positivity was detected in 19 tumors (30.6%), where 84.2% were due to high trisomy or polysomy and only 3 cases (15.8%) were MET gene amplification. The overall MET protein overexpression was well correlated with MET SISH positivity. The concurrent MET SISH positivity and KRAS mutation, not each alone, was an independent poor prognostic factor of disease-free survival only in pancreatobiliary subtype of A-ACs, but not in intestinal subtype. Concurrent MET SISH positivity and KRAS mutation may predict a high risk of recurrence in pancreatobiliary subtype of A-ACs, indicating those markers could be potent candidates for a new therapeutic target in this cancer type. MET IHC can be used as a reliable tool screening for MET copy number status in ampullary cancers.

One-year experience with single incision laparoscopic cholecystectomy in a single center: without the use of inverse triangulation

Purpose Single incision laparoscopic cholecystectomy (SILC) is generally performed with the use of inverse triangulation. In this study, we performed 3-channel or 4-channel SILC without the use of inverse triangulation. We evaluated the adequacy and feasibility of SILC using our surgical method. Methods We retrospectively reviewed our series of 309 SILCs performed between March 2014 and February 2015. Results Among 309 SILCs, male were 148 and female were 161 patients, mean age was 48.7 ± 15.3 years old and mean body mass index was 24.8 ± 3.8 kg/m2. Forty patients had previously undergone abdominal surgery including 6 cases of upper abdominal surgery. SILC after percutaneous transhepatic gallbladder (GB) drainage was completed in 8.7% of cases. There were 10 cases of emergency SILC. SILC was performed for noncomplicated GB including symptomatic GB stone and polyp in 66.7% of cases, acute cholecystitis in 33.3%. Overall, 96.8% of procedures were successfully completed without additional port. The reason for addition of an extra port or open conversion included technical difficulties due to severe adhesion and bleeding. The mean operating time was 60.7 ± 22.3 minutes. The overall complication rate was 4.8%: 9 patients of wound seroma, 1 case of bile leakage from GB bed, 4 cases of intra-abdominal abscess or fluid collection, and 1 case of incisional hernia were developed. There was no case of common bile duct injury. Conclusion Our surgical method of SILC without the use of inverse triangulation is safe, feasible and effective technique.

Laparoscopic treatment for post-cholecystectomy Mirizzi syndrome.

The remnant cystic duct or gallbladder neck calculus may rarely result in post-cholecystectomy Mirizzi syndrome. Various managements have been proposed for the treatment of post-cholecystectomy Mirizzi syndrome. Some previous cases of post-cholecystectomy Mirizzi syndrome have been managed with open cholecystectomy and endoscopically. We report a case of a laparoscopic stone removal of post-cholecystectomy Mirizzi syndrome that developed 7 months after laparoscopic cholecystectomy. To our knowledge, this is the first case of laparoscopic management of post-cholecystectomy Mirizzi syndrome. The mechanism, diagnosis and treatment of post-cholecystectomy Mirizzi syndrome are discussed.