Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

Background: Topical recombinant human epidermal growth factor (rhEGF) is effective in the treatment of diabetic foot ulcers, surgical wounds, burns, and scars. Binding of EGF to EGF receptors results in cell proliferation and differentiation. Objective: This study aimed to evaluate the efficacy of topical rhEGF ointment compared with that of topical mupirocin in healing herpes zoster (HZ) lesions. Methods: Thirty patients diagnosed with typical HZ were recruited in August, 2018. The rats were randomly divided into two groups: topical mupirocin and topical rhEGF ointment. HZ lesions were evaluated using the Vancouver Scar Scale (VSS) at the initial visit, 1st, 2nd, and 4th weeks. Results: The total number of recruited patients (n=30) included males (n=16, 53.3%) and females (n=14, 46.7%) with a mean age of 58.2. The proportion of patients with a 50% reduction in the VSS score (VSS 50) at 2nd week was significantly higher in the rhEGF group (33.0% vs. 72.0%, respectively, p=0.035). The complete resolution rate (VSS=0, 1) at 4th week was also higher in the rhEGF group (17.5% vs. 50.0%, p=0.03). Conclusion Topical rhEGF showed a more rapid treatment response and anti-scarring effect than topical mupirocin in patients with HZ lesions.

Background/Aims: Real-world, clinical practice data are lacking about sofosbuvir/ ribavirin (SOF/RBV) treatment of Korean patients with hepatitis C virus genotype 2 (HCV GT2) infection. This study investigated the efficacy and safety of SOF/RBV in Korean patients with HCV GT2 infection and clinical factors predicting sustained virological response 12 weeks (SVR12) after the end of SOF/RBV treatment. Methods: A total of 181 patients with HCV GT2 with/without cirrhosis were treated with SOF/RBV for 16/12 weeks. Rapid virological response (RVR) was defined as non-detectable HCV RNA at 4 weeks. Results: The RVR rate was 80.7% (146/181), the end of treatment response rate was 97.8% (177/181) and the SVR12 rate was 92.8% (168/181). Of eight patients with relapse, four did not achieve RVR. Three patients had a history of hepatocellular carcinoma (HCC). Multivariable analysis showed that RVR (p = 0.015) and no previous history of HCC (p = 0.007) were associated with SVR12. Factors significantly contributing to RVR included cirrhosis, creatinine concentration, and pre-treatment HCV RNA level. SVR12 rate was significantly higher in RVR (+) than RVR (–) patients (95.2% vs. 82.9%, p = 0.011) and also significantly higher in patients without than with a history of HCC (94.1% vs. 72.7%, p = 0.008). During treatment, 80/181 patients (44.2%) experienced mild to moderate adverse events, with 32 (17.7%) requiring RBV dose reductions due to anemia. Conclusions SOF/RBV treatment was effective and tolerable in HCV GT2 patients. RVR and no previous history of HCC were positive predictors of SVR12.

Background/Aims: Real-world, clinical practice data are lacking about sofosbuvir/ ribavirin (SOF/RBV) treatment of Korean patients with hepatitis C virus genotype 2 (HCV GT2) infection. This study investigated the efficacy and safety of SOF/RBV in Korean patients with HCV GT2 infection and clinical factors predicting sustained virological response 12 weeks (SVR12) after the end of SOF/RBV treatment. Methods: A total of 181 patients with HCV GT2 with/without cirrhosis were treated with SOF/RBV for 16/12 weeks. Rapid virological response (RVR) was defined as non-detectable HCV RNA at 4 weeks. Results: The RVR rate was 80.7% (146/181), the end of treatment response rate was 97.8% (177/181) and the SVR12 rate was 92.8% (168/181). Of eight patients with relapse, four did not achieve RVR. Three patients had a history of hepatocellular carcinoma (HCC). Multivariable analysis showed that RVR (p = 0.015) and no previous history of HCC (p = 0.007) were associated with SVR12. Factors significantly contributing to RVR included cirrhosis, creatinine concentration, and pre-treatment HCV RNA level. SVR12 rate was significantly higher in RVR (+) than RVR (–) patients (95.2% vs. 82.9%, p = 0.011) and also significantly higher in patients without than with a history of HCC (94.1% vs. 72.7%, p = 0.008). During treatment, 80/181 patients (44.2%) experienced mild to moderate adverse events, with 32 (17.7%) requiring RBV dose reductions due to anemia. Conclusions SOF/RBV treatment was effective and tolerable in HCV GT2 patients. RVR and no previous history of HCC were positive predictors of SVR12.

Purpose: When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft. Methods: This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts. Results: The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes. Conclusion The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Purpose: This study was conducted to determine the effectiveness of immune checkpoint inhibitors (ICIs) in recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) after platinum-containing chemotherapy. We also identified clinical biomarkers which may be predictive of patient prognosis. Materials and Methods: We analyzed 125 patients with R/M HNSCC who received ICIs, retrospectively. Overall response rate (ORR) was the primary study outcome. Overall survival (OS) and progression-free survival (PFS) were the secondary study outcomes. Results: The patients received anti–programmed cell death protein-1 (PD-1) (n=73, 58%), anti–programmed death-ligand 1 (PD-L1) (n=24, 19%), or a combination of anti–PD-1/PD-L1 and anti–cytotoxic T-lymphocyte antigen 4 (n=28, 22%). The median age was 57 years (range, 37 to 87). The location of the primary tumor was in the oral cavity in 28% of the cases, followed by oropharynx (27%), hypopharynx (20%), and larynx (12%). The ORR was 15% (19/125). With 12.3 months of median follow-up, median PFS was 2.7 months. Median OS was 10.8 months. A neutrophil-to-lymphocyte ratio (NLR) > 4 was significantly associated with poor response to ICIs (odds ratio, 0.30; p=0.022). A sum of the target lesions > 40 mm (hazard ratio [HR], 1.53; p=0.046] and a NLR > 4 (HR, 1.75; p=0.009) were considered to be predictive markers of short PFS. A poor performance status (HR, 4.79; p < 0.001), a sum of target lesions > 40 mm (HR, 1.93; p=0.025), and an NLR > 4 (HR, 3.36; p < 0.001) were the significant predictors for poor survival. Conclusion ICIs exhibited favorable antitumor activity in R/M HNSCC. Clinically, our findings can be used to recognize patients benefit from receiving ICI.

Background/Aims: Glecaprevir/pibrentasvir (G/P) is a combination of direct-acting antiviral agents that is an approved treatment for chronic infections by all six hepatitis C virus (HCV) genotypes. However, there are limited data on the effect of G/P in Korean patients in actual real-world settings. We evaluated the real-life effectiveness and safety of G/P at a single institution in Korea. Methods: This retrospective, observational, cohort study used sustained virologic response at 12 weeks after treatment completion (SVR12) as the primary effectiveness endpoint. Safety and tolerability were also determined. Results: We examined 267 individuals who received G/P for chronic HCV infections. There were 148 females (55.4%), and the overall median age was 63.0 years (range, 25 to 87 years). Eightythree patients (31.1%) had HCV genotype-1 and 182 (68.2%) had HCV-2. A total of 212 patients (79.4%) were HCV treatment-naïve, 200 (74.9%) received the 8-week treatment, 13 (4.9%) had received prior treatment for hepatocellular carcinoma, 37 (13.7%) had chronic kidney disease stage 3 or higher, and 10 (3.7%) were receiving dialysis. Intention to treat (ITT) analysis indicated that 256 (95.9%) achieved SVR12. A modified ITT analysis indicated that SVR12 was 97.7% (256/262). Six patients failed therapy because of posttreatment relapse. SVR12 was significantly lower in those who received prior sofosbuvir treatment (p=0.002) and those with detectable HCV RNA at week 4 (p=0.027). Seventy patients (26.2%) experienced one or more adverse events, and most of them were mild. Conclusions These real-life data indicated that G/P treatment was highly effective and well tolerated, regardless of viral genotype or patient comorbidities.

Purpose: When splitting a liver for adult and pediatric graft recipients, the retained left medial section (S4) will undergo ischemic necrosis and the right trisection graft becomes an extended right liver (ERL) graft. We investigated the fates of the retained S4 and its prognostic impact in adult split liver transplantation (SLT) using an ERL graft. Methods: This was a retrospective analysis of 25 adult SLT recipients who received split ERL grafts. Results: The mean model for end-stage liver disease (MELD) score was 27.3 ± 10.9 and graft-recipient weight ratio (GRWR) was 1.98 ± 0.44. The mean donor age was 26.5 ± 7.7 years. The split ERL graft weight was 1,181.5 ± 252.8 g, which resulted in a mean GRWR of 1.98 ± 0.44. Computed tomography of the retained S4 parenchyma revealed small ischemic necrosis in 16 patients (64.0%) and large ischemic necrosis in the remaining 9 patients (36.0%). No S4-associated biliary complications were developed. The mean GRWR was 1.87 ± 0.43 in the 9 patients with large ischemic necrosis and 2.10 ± 0.44 in the 15 cases with small ischemic necrosis (P = 0.283). The retained S4 parenchyma showed gradual atrophy on follow-up imaging studies. The amount of S4 ischemic necrosis was not associated with graft (P = 0.592) or patient (P = 0.243) survival. A MELD score of >30 and pretransplant ventilator support were associated with inferior outcomes. Conclusion The amount of S4 ischemic necrosis is not a prognostic factor in adult SLT recipients, probably due to a sufficiently large GRWR.

Purpose: This study was conducted to determine the effectiveness of immune checkpoint inhibitors (ICIs) in recurrent or metastatic head and neck squamous cell carcinoma (R/M HNSCC) after platinum-containing chemotherapy. We also identified clinical biomarkers which may be predictive of patient prognosis. Materials and Methods: We analyzed 125 patients with R/M HNSCC who received ICIs, retrospectively. Overall response rate (ORR) was the primary study outcome. Overall survival (OS) and progression-free survival (PFS) were the secondary study outcomes. Results: The patients received anti–programmed cell death protein-1 (PD-1) (n=73, 58%), anti–programmed death-ligand 1 (PD-L1) (n=24, 19%), or a combination of anti–PD-1/PD-L1 and anti–cytotoxic T-lymphocyte antigen 4 (n=28, 22%). The median age was 57 years (range, 37 to 87). The location of the primary tumor was in the oral cavity in 28% of the cases, followed by oropharynx (27%), hypopharynx (20%), and larynx (12%). The ORR was 15% (19/125). With 12.3 months of median follow-up, median PFS was 2.7 months. Median OS was 10.8 months. A neutrophil-to-lymphocyte ratio (NLR) > 4 was significantly associated with poor response to ICIs (odds ratio, 0.30; p=0.022). A sum of the target lesions > 40 mm (hazard ratio [HR], 1.53; p=0.046] and a NLR > 4 (HR, 1.75; p=0.009) were considered to be predictive markers of short PFS. A poor performance status (HR, 4.79; p < 0.001), a sum of target lesions > 40 mm (HR, 1.93; p=0.025), and an NLR > 4 (HR, 3.36; p < 0.001) were the significant predictors for poor survival. Conclusion ICIs exhibited favorable antitumor activity in R/M HNSCC. Clinically, our findings can be used to recognize patients benefit from receiving ICI.