Jin-Hyeok Hwang

Seoul National University, Sŏul, Seoul, South Korea

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Publications (110)411.83 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: Background/aims: To evaluate the adjuvant effects of N-acetylcysteine (NAC) on first-line sequential therapy (SQT) for Helicobacter pylori infection. Methods: Patients with H. pylori infections were randomly assigned to receive sequential therapy with (SQT+NAC group, n=49) or without (SQT-only group, n=50) NAC. Sequential therapy consisted of rabeprazole 20 mg and amoxicillin 1 g for the first 5 days, followed by rabeprazole 20 mg, clarithromycin 500 mg and metronidazole 500 mg for the remaining 5 days; all drugs were administered twice daily. For the SQT+NAC group, NAC 400 mg b.i.d. was added for the first 5 days of sequential therapy. H. pylori eradication was evaluated 4 weeks after the completion of therapy. Results: The eradication rates by intention-to-treat analysis were 58.0% in the SQT-only group and 67.3% in the SQT+NAC group (p=0.336). The eradication rates by per-protocol analysis were 70.0% in the SQT-only group and 80.5% in the SQT+NAC group (p=0.274). Compliance was very good in both groups (SQT only/SQT+NAC groups 95.2%/100%, p=0.494). There was no significant difference in the adverse event rates between groups (SQT-only/SQT+NAC groups 26.2%/26.8%, p=0.947). Conclusions: The H. pylori eradication rate was numerically higher in the SQT+NAC group than in the SQT-only group. As our data did not reach statistical significance, larger trials are warranted.
    Gut and Liver 09/2015; DOI:10.5009/gnl15048 · 1.81 Impact Factor
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    ABSTRACT: The clinical significance of pancreatic intraepithelial neoplasia (PanIN) lesions in non-neoplastic pancreata of pancreatic ductal adenocarcinoma (PDAC) patients remains controversial. As chronic inflammation has been recently demonstrated to promote dissemination of in situ precancerous lesions, we investigated the prognostic significance of PanINs associated with chronic pancreatitis (CP) in PDAC patients. This retrospective study analyzed 125 curatively resected PDAC specimens for the presence of PanIN and CP. Univariate and multivariate analyses were performed to identify significant predictive factors for poor disease-free survival (DFS) and overall survival (OS). Immunohistochemical staining for E-cadherin and S100A4, markers of epithelial-mesenchymal transition, was performed on resected specimens containing PanIN-3 lesions. CP was observed in 27.2% (34/125) and PanIN-3 in 25.6% (32/125) of specimens. In the presence of CP, PanIN-3 was significantly associated with decreased survival (DFS: 4.3 vs. 15.5 months, p = 0.021; OS: 16.3 vs. 30.9 months, p = 0.004). PanIN-3 was not a prognostic factor in the absence of CP. The presence of both PanIN-3 and CP was associated with a reduced survival compared to the other cases, in both univariate (DFS: p = 0.039; OS: p = 0.023) and multivariate (DFS: p = 0.020; OS: p = 0.076) analyses. Furthermore, E-cadherin loss and S100A4 expression were more frequently observed in PanIN-3 lesions of CP specimens than in those of non-CP specimens, although not statistically significant. PanIN-3 in association with CP is a significant prognostic factor for decreased survival in PDAC patients, suggesting that chronic inflammation may accelerate the progression of preinvasive high-grade PanIN. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.
    Cancer Science 07/2015; DOI:10.1111/cas.12744 · 3.52 Impact Factor
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    Woo Hyun Paik · Jin-Hyeok Hwang
    Clinical Endoscopy 05/2015; 48(3):185-6. DOI:10.5946/ce.2015.48.3.185
  • Gastrointestinal Endoscopy 05/2015; 81(5):AB416. DOI:10.1016/j.gie.2015.03.1591 · 5.37 Impact Factor
  • Gastroenterology 04/2015; 148(4):S-293-S-294. DOI:10.1016/S0016-5085(15)30971-9 · 16.72 Impact Factor
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    ABSTRACT: Few studies have evaluated the presence of hepatic or peritoneal metastasis as a prognostic factor in patients with metastatic pancreatic ductal adenocarcinoma (PDAC). This study aimed to elucidate the prognostic value of the initial metastatic, extrahepatic, or hepatic site in patients with metastatic PDAC.Between January 2007 and December 2013, the medical records of 343 patients with metastatic PDAC treated at Seoul National University Bundang Hospital were retrospectively reviewed. Patients were classified as having extrahepatic metastasis alone (EH), hepatic metastasis alone (LV), and both hepatic and extrahepatic metastasis (BOTH).The median age was 67 years; 207 patients were men. Patients were classified as having EH (111 patients), LV (106), and BOTH (126). Totally, 212 patients underwent chemotherapy with a FOLFIRINOX (23 patients) or gemcitabine-based regimen (189). On multivariate analysis, an ECOG score ≥2 (hazard ratio [HR]: 3.2, 95% confidence interval [CI]: 2.2-4.5), albumin < 35 g/L (HR: 1.6, 95% CI: 1.1-2.3), C-reactive protein > 10 mg/L (HR: 2.3, 95% CI: 1.6-3.2), neutrophil-lymphocyte ratio > 5 (HR: 1.4, 95% CI: 1.0-2.0), no chemotherapy (HR: 2.0, 95% CI: 1.0-4.1), and metastatic site (LV, HR: 2.1, 95% CI: 1.4-3.1; BOTH, HR: 2.2, 95% CI: 1.6-3.2) were significantly associated with shorter overall survival (OS). Considering the initial metastatic site, the median OS of patients with EH, LV, and BOTH were 7.5 (95% CI: 6.3-8.8), 4.8 (95% CI: 4.1-5.5), and 2.4 (95% CI: 1.9-2.9) months, respectively.The initial metastatic site is significantly and independently associated with OS in patients with metastatic PDAC, serving as an effective prognostic factor.
    Gastroenterology 04/2015; 148(4):S-942-S-943. DOI:10.1016/S0016-5085(15)33215-7 · 16.72 Impact Factor
  • Gastroenterology 04/2015; 148(4):S-393. DOI:10.1016/S0016-5085(15)31321-4 · 16.72 Impact Factor
  • Gastroenterology 04/2015; 148(4):S-394-S-395. DOI:10.1016/S0016-5085(15)31327-5 · 16.72 Impact Factor
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    ABSTRACT: Information regarding postoperative thromboembolism in curatively resected pancreatic cancer is limited. This study aimed to assess the incidence and significance of postoperative thromboembolism. We retrospectively reviewed the medical records of 121 curatively resected pancreatic cancer patients. Early and late thromboembolisms were defined as events that occurred within 1 year and after 1 year, respectively. Twenty-two patients (18%) experienced thromboembolism. Seven thromboembolic events occurred within 1 month (7, 6%), and the incidence rate decreased over time. Ten (63%) of the 16 patients with early thromboembolism experienced thromboembolism before or at the same time as recurrence; however, 5 (83%) of the 6 patients with late thromboembolism experienced recurrence before thromboembolism (P = .005). A significant difference in recurrence-free survival (P = .016) and borderline difference in overall survival (P = .050) were observed between patients with early thromboembolism and others. Thromboembolic events after curative surgery are prevalent in pancreatic cancer, especially within 1 month. Thromboembolic events within 1 year of surgery should be cautiously monitored. Copyright © 2015 Elsevier Inc. All rights reserved.
    American journal of surgery 04/2015; DOI:10.1016/j.amjsurg.2014.12.051 · 2.29 Impact Factor
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    ABSTRACT: The role of carcinoembryonic antigen (CEA) in pancreatic cancer remains poorly understood. Therefore, this study aimed to determine whether CEA is complementary to carbohydrate antigen 19-9 (CA19-9) in prognosis prediction after pancreatic cancer curative resection. We retrospectively reviewed records of 144 stage II curatively resected pancreatic cancer patients with preoperative and postoperative CEA and CA19-9 levels. Patients with normal preoperative CA19-9 were excluded. R0 resection margin, adjuvant treatment, and absence of angiolymphatic invasion were associated with better overall survival. There was no significant difference in median survival according to preoperative CEA levels. However, patients with normal postoperative CA19-9 (59.8 vs.16.2 months, P < 0.001) and CEA (29.4 vs. 9.3 months, P = 0.001) levels had longer overall survival than those with elevated levels. Among 76 patients with high postoperative CA19-9 levels, a better prognosis was observed in those with normal postoperative CEA levels than in those with elevated levels (19.1 vs. 9.3 months, P = 0.004). Postoperative CEA and CA19-9 levels are valuable prognostic markers in resected pancreatic cancer. Normal postoperative CEA levels indicate longer survival, even in patients with elevated postoperative CA19-9. Graphical Abstract
    Journal of Korean Medical Science 03/2015; 30(3):259-63. DOI:10.3346/jkms.2015.30.3.259 · 1.27 Impact Factor
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    ABSTRACT: To evaluate when Helicobacter pylori (H. pylori) eradication therapy (ET) should be started in patients with peptic ulcer bleeding (PUB). Clinical data concerning adults hospitalized with PUB were retrospectively collected and analyzed. Age, sex, type and stage of peptic ulcer, whether endoscopic therapy was performed or not, methods of H. pylori detection, duration of hospitalization, and specialty of the attending physician were investigated. Factors influencing the confirmation of H. pylori infection prior to discharge were determined using multiple logistic regression analysis. The H. pylori eradication rates of patients who received ET during hospitalization and those who commenced ET as outpatients were compared. A total of 232 patients with PUB were evaluated for H. pylori infection by histology and/or rapid urease testing. Of these patients, 53.7% (127/232) had confirmed results of H. pylori infection prior to discharge. In multivariate analysis, duration of hospitalization and ulcer stage were factors independently influencing whether H. pylori infection was confirmed before or after discharge. Among the patients discharged before confirmation of H. pylori infection, 13.3% (14/105) were lost to follow-up. Among the patients found to be H. pylori-positive after discharge, 41.4% (12/29) did not receive ET. There was no significant difference in the H. pylori eradication rate between patients who received ET during hospitalization and those who commenced ET as outpatients [intention-to-treat: 68.8% (53/77) vs 60% (12/20), P = 0.594; per-protocol: 82.8% (53/64) vs 80% (12/15), P = 0.723]. Because many patients with PUB who were discharged before H. pylori infection status was confirmed lost an opportunity to receive ET, we should confirm H. pylori infection and start ET prior to discharge.
    02/2015; 21(8):2497-503. DOI:10.3748/wjg.v21.i8.2497
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    ABSTRACT: Enhanced computed tomography (CT) is widely used for evaluating acute biliary pain in the emergency department (ED). However, concern about radiation exposure from CT has also increased. We investigated the usefulness of pre-contrast CT for differential diagnosis in middle-aged subjects with suspected biliary pain.A total of 183 subjects, who visited the ED for suspected biliary pain from January 2011 to December 2012, were included. Retrospectively, pre-contrast phase and multiphase CT findings were reviewed and the detection rate of findings suggesting disease requiring significant treatment by noncontrast CT (NCCT) was compared with cases detected by multiphase CT.Approximately 70% of total subjects had a significant condition, including 1 case of gallbladder cancer and 126 (68.8%) cases requiring intervention (122 biliary stone-related diseases, 3 liver abscesses, and 1 liver hemangioma). The rate of overlooking malignancy without contrast enhancement was calculated to be 0% to 1.5%. Biliary stones and liver space-occupying lesions were found equally on NCCT and multiphase CT. Calculated probable rates of overlooking acute cholecystitis and biliary obstruction were maximally 6.8% and 4.2% respectively. Incidental significant finding unrelated with pain consisted of 1 case of adrenal incidentaloma, which was also observed in NCCT.NCCT might be sufficient to detect life-threatening or significant disease requiring early treatment in young adults with biliary pain.
    Medicine 02/2015; 94(7):e546. DOI:10.1097/MD.0000000000000546 · 5.72 Impact Factor
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    ABSTRACT: The effects of diabetes mellitus (DM) on sensitivity of fluorine-18 fluorodeoxyglucose positron emission tomography coupled with computed tomography ((18)F-FDG PET/CT) for diagnosing pancreatic ductal adenocarcinomas (PDACs) is not well known. This study was aimed to evaluate the effects of DM on the validity of (18)F-FDG PET/CT in PDAC. A total of 173 patients with PDACs who underwent (18)F-FDG PET/CT were enrolled (75 in the DM group and 98 in the non-DM group). The maximum standardized uptake values (SUVsmax) were compared. The mean SUVmax was significantly lower in the DM group than in the non-DM group (4.403 vs 5.998, P = .001). The sensitivity of SUVmax (cut-off value 4.0) was significantly lower in the DM group than in the non-DM group (49.3% vs 75.5%, P < .001) and also lower in normoglycemic DM patients (n = 24) than in non-DM patients (54.2% vs 75.5%, P = .038). DM contributes to a lower SUVmax of (18)F-FDG PET/CT in patients with PDACs. Copyright © 2015 Elsevier Inc. All rights reserved.
    The American Journal of Surgery 12/2014; 209(4). DOI:10.1016/j.amjsurg.2014.06.038 · 2.29 Impact Factor
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    ABSTRACT: Background/Aims Retreatment after initial treatment failure for Helicobacter pylori is very challenging. The purpose of this study was to evaluate the efficacies of moxifloxacin-containing triple and bismuth-containing quadruple therapy. Methods A total of 151 patients, who failed initial H. pylori treatment, were included in this retrospective cohort study. The initial regimens were standard triple, sequential, or concomitant therapy, and the efficacies of the two following second-line treatments were evaluated: 7-day moxifloxacin-containing triple therapy (rabeprazole 20 mg twice a day, amoxicillin 1,000 mg twice a day, and moxifloxacin 400 mg once daily) and 7-day bismuth-containing quadruple therapy (rabeprazole 20 mg twice a day, tetracycline 500 mg 4 times a day, metronidazole 500 mg 3 times a day, and tripotassium dicitrate bismuthate 300 mg 4 times a day). Results The overall eradication rates after moxifloxacin-containing triple therapy and bismuth-containing quadruple therapy were 69/110 (62.7%) and 32/41 (78%), respectively. Comparison of the two regimens was performed in the patients who failed standard triple therapy, and the results revealed eradication rates of 14/28 (50%) and 32/41 (78%), respectively (p=0.015). The frequency of noncompliance was not different between the two groups, and there were fewer adverse effects in the moxifloxacin-containing triple therapy group (2.8% vs 7.3%, p=0.204 and 25.7% vs 43.9%, p=0.031, respectively). Conclusions Moxifloxacin-containing triple therapy, a recommended second-line treatment for initial concomitant or sequential therapy failure, had insufficient efficacy.
    Gut and liver 11/2014; 8(6):605-11. DOI:10.5009/gnl13303 · 1.81 Impact Factor
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    ABSTRACT: Background/Aims There are several methods for obtaining tissue samples to diagnose malignant biliary strictures during endoscopic retrograde cholangiopancreatography (ERCP). However, each method has only limited sensitivity. This study aimed to evaluate the diagnostic accuracy of a combined triple-tissue sampling (TTS) method (on-site bile aspiration cytology, brush cytology, and forceps biopsy). Methods We retrospectively reviewed 168 patients with suspicious malignant biliary strictures who underwent double-tissue sampling (DTS; n=121) or TTS (n=47) via ERCP at our institution from 2004 to 2011. Results Among the 168 patients reviewed, 117 patients (69.6%) were eventually diagnosed with malignancies. The diagnostic sensitivity for cancer was significantly higher in the TTS group than the DTS group (85.0% vs 64.9%, respectively; p=0.022). Furthermore, the combination of brush cytology and forceps biopsy was superior to the other method combinations in the DTS group. With respect to cancer type (cholangiocarcinoma vs noncholangiocarcinoma), interestingly, the diagnostic sensitivity was higher for cholangiocarcinoma in the TTS group than the DTS group (100% vs 69.4%, respectively; p<0.001) but not for the non-cholangiocarcinoma patients (57.1% vs 57.1%, respectively). Conclusions TTS can provide an improved diagnostic accuracy in suspicious malignant biliary strictures, particularly for cholangiocarcinoma.
    Gut and liver 11/2014; 8(6):669-73. DOI:10.5009/gnl13292 · 1.81 Impact Factor
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    ABSTRACT: Goals and background: Long-term outcomes of symptomatic gallbladder (GB) sludge are not fully established. This study aimed to determine whether patients with symptomatic GB sludge could experience subsequent biliary events. Study: This study investigated consecutive patients who presented with typical biliary pain and underwent abdominal ultrasonography from March 2003 to December 2012. A prospectively maintained database of these patients, excluding those with gallstones, was reviewed retrospectively. We compared the development of biliary events such as acute cholecystitis, acute cholangitis, and acute pancreatitis between both GB sludge and non-GB sludge cohorts. Results: In all, 58 and 70 patients were diagnosed with and without GB sludge, respectively. The 5-year cumulative biliary event rate was significantly higher in the GB sludge (33.9% vs. 15.8%, P=0.021) and the hazard ratio of subsequent biliary events was 2.573 (95% confidence interval, 1.124-5.889; P=0.025) in patients with GB sludge. The 5-year cumulative rate of each biliary event was higher in the GB sludge cohort (15.6% vs. 5.3% in acute cholecystitis, 15.5% vs. 5.3% in acute cholangitis, 18.4% vs. 11.1% in acute pancreatitis, respectively), although it was not statistically significant. Among the GB sludge cohort, subsequent biliary events were less frequent in patients who underwent cholecystectomy compared with those who did not (2/16, 12.5% vs. 17/42, 40.4%; P=0.067). Conclusions: GB sludge accompanying typical biliary pain can cause subsequent biliary events and cholecystectomy may prevent subsequent biliary events. Therefore, GB sludge would be considered as a culprit of biliary events.
    Journal of Clinical Gastroenterology 08/2014; Publish Ahead of Print(7). DOI:10.1097/MCG.0000000000000202 · 3.50 Impact Factor
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    ABSTRACT: Background The durability of off-treatment virologic responses has not been fully elucidated in chronic hepatitis B (CHB) patients who have previously achieved complete virologic suppression with nucleos(t)ide analog (NA) therapy. This study aimed to assess off-treatment virologic relapse rates and to characterize the outcomes of subsequent re-treatment in CHB patients who have discontinued oral NA following complete virologic suppression. Methods Ninety-five CHB patients who showed complete virologic suppression were withdrawn from NAs: entecavir, lamivudine, and clevudine in 67, 15, and 13 patients, respectively. Consolidation therapy was given for 6 and 12 months for HBeAg-positive and -negative CHB, respectively, before cessation. Virologic relapse was managed with the same NA that had induced complete virologic response before discontinuation. Results The cumulative rates of virologic relapse at 12 and 24 months were 73.8% and 87.1%, respectively. The relapse rates were independent of HBeAg positivity, HBeAg seroconversion, and type of oral NA. In a multivariate analysis, duration of oral NA therapy was the only significant predicting factor associated with off-treatment virologic relapse. Although the majority of patients regained complete virologic suppression, some patients did not respond to re-treatment with the initial NA and developed genotypic resistance. Conclusions NA consolidation therapy for 6 and 12 months is associated with high off-treatment virologic relapse in HBeAg-positive and -negative CHB patients, respectively. Drugs with high genetic barriers to resistance should be considered as a rescue therapy for off-treatment relapse in CHB.
    BMC Infectious Diseases 08/2014; 14(1):439. DOI:10.1186/1471-2334-14-439 · 2.61 Impact Factor
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    ABSTRACT: Aim: To investigate the prognostic factors determining the success rate of non-surgical treatment in the management of post-operative bile duct injuries (BDIs). Methods: The study patients were enrolled from the pancreatobiliary units of a tertiary teaching hospital for the treatment of BDIs after hepatobiliary tract surgeries, excluding operations for liver transplantation and malignancies, from January 1999 to August 2010. A total of 5167 patients underwent operations, and 77 patients had BDIs following surgery. The primary end point was the treatment success rate according to different types of BDIs sustained using endoscopic or percutaneous hepatic approaches. The type of BDI was defined using one of the following diagnostic tools: endoscopic retrograde cholangiography, percutaneous transhepatic cholangiography, computed tomography scan, and magnetic resonance cholangiography. Patients with a final diagnosis of BDI underwent endoscopic and/or percutaneous interventions for the treatment of bile leak and/or stricture if clinically indicated. Patient consent was obtained, and study approval was granted by the Institutional Review Board in accordance with the legal regulations of the Human Clinical Research Center at the Seoul National University Hospital in Seoul, South Korea. Results: A total of 77 patients were enrolled in the study. They were divided into three groups according to type of BDI. Among them, 55 patients (71%) underwent cholecystectomy. Thirty-six patients (47%) had bile leak only (type 1), 31 patients had biliary stricture only (type 2), and 10 patients had both bile leak and biliary stricture (type 3). Their initial treatment modalities were non-surgical. The success rate of non-surgical treatment in each group was as follows: BDI type 1: 94%; type 2: 71%; and type 3: 30%. Clinical parameters such as demographic factors, primary disease, operation method, type of operation, non-surgical treatment modalities, endoscopic procedure steps, type of BDI, time to diagnosis and treatment duration were evaluated to evaluate the prognostic factors affecting the success rate. The type of BDI was a statistically significant prognostic factor in determining the success rate of non-surgical treatment. In addition, a shorter time to diagnosis of BDI after the operation correlated significantly with higher success rates in the treatment of type 1 BDIs. Conclusion: Endoscopic or percutaneous hepatic approaches can be used as an initial treatment in type 1 and 2 BDIs. However, surgical intervention is a treatment of choice in type 3 BDI.
    World Journal of Gastroenterology 06/2014; 20(22):6924-31. DOI:10.3748/wjg.v20.i22.6924 · 2.37 Impact Factor
  • Gastroenterology 05/2014; 146(5):S-513. DOI:10.1016/S0016-5085(14)61857-6 · 16.72 Impact Factor
  • Gastroenterology 05/2014; 146(5):S-880. DOI:10.1016/S0016-5085(14)63207-8 · 16.72 Impact Factor

Publication Stats

909 Citations
411.83 Total Impact Points


  • 2008–2015
    • Seoul National University
      • • Department of Internal Medicine
      • • Liver Research Institute
      Sŏul, Seoul, South Korea
  • 2005–2015
    • Seoul National University Bundang Hospital
      • • Department of Surgery
      • • Department of Medicine
      Sŏul, Seoul, South Korea
  • 2003–2013
    • Seoul National University Hospital
      • Department of Internal Medicine
      Sŏul, Seoul, South Korea