Purpose: We aimed to identify changes in surgical indications in patients with ulcerative colitis (UC) in the biologics era in a single tertiary center. Methods: In this retrospective observational study, 108 patients with UC who underwent abdominal surgery for UC at Seoul National University Hospital from 2000 to 2021 were included. We compared the total number of patients undergoing UC before and after the introduction of biologic therapy. Results: Of the 108 patients with UC (male, 59 and female, 49; mean age, 46.8 years), 30 (27.8%) underwent surgery for neoplasms and 78 (72.2%) for medical intractability without neoplasms. The duration between diagnosis and surgery varied significantly (126.00 months vs. 60.50 months, P = 0.001). A significant difference was also noted in the surgical indications according to time (P = 0.02). Between 2000 and 2010, 12 patients (19.4%) underwent surgery for UC with neoplasms and 50 (80.6%) for UC without neoplasms, while between 2011 and 2021, 18 (39.1%) and 28 patients (60.9%) underwent surgery for UC with and without neoplasms, respectively. Conclusion Since 2011, when biological agents were covered by insurance in South Korea, there has been a relative increase in the incidence of surgical indications for neoplasia cases. Focusing on closely monitoring individuals with longterm UC for neoplasms is necessary.

Purpose: We aimed to identify changes in surgical indications in patients with ulcerative colitis (UC) in the biologics era in a single tertiary center. Methods: In this retrospective observational study, 108 patients with UC who underwent abdominal surgery for UC at Seoul National University Hospital from 2000 to 2021 were included. We compared the total number of patients undergoing UC before and after the introduction of biologic therapy. Results: Of the 108 patients with UC (male, 59 and female, 49; mean age, 46.8 years), 30 (27.8%) underwent surgery for neoplasms and 78 (72.2%) for medical intractability without neoplasms. The duration between diagnosis and surgery varied significantly (126.00 months vs. 60.50 months, P = 0.001). A significant difference was also noted in the surgical indications according to time (P = 0.02). Between 2000 and 2010, 12 patients (19.4%) underwent surgery for UC with neoplasms and 50 (80.6%) for UC without neoplasms, while between 2011 and 2021, 18 (39.1%) and 28 patients (60.9%) underwent surgery for UC with and without neoplasms, respectively. Conclusion Since 2011, when biological agents were covered by insurance in South Korea, there has been a relative increase in the incidence of surgical indications for neoplasia cases. Focusing on closely monitoring individuals with longterm UC for neoplasms is necessary.

Purpose: We aimed to identify changes in surgical indications in patients with ulcerative colitis (UC) in the biologics era in a single tertiary center. Methods: In this retrospective observational study, 108 patients with UC who underwent abdominal surgery for UC at Seoul National University Hospital from 2000 to 2021 were included. We compared the total number of patients undergoing UC before and after the introduction of biologic therapy. Results: Of the 108 patients with UC (male, 59 and female, 49; mean age, 46.8 years), 30 (27.8%) underwent surgery for neoplasms and 78 (72.2%) for medical intractability without neoplasms. The duration between diagnosis and surgery varied significantly (126.00 months vs. 60.50 months, P = 0.001). A significant difference was also noted in the surgical indications according to time (P = 0.02). Between 2000 and 2010, 12 patients (19.4%) underwent surgery for UC with neoplasms and 50 (80.6%) for UC without neoplasms, while between 2011 and 2021, 18 (39.1%) and 28 patients (60.9%) underwent surgery for UC with and without neoplasms, respectively. Conclusion Since 2011, when biological agents were covered by insurance in South Korea, there has been a relative increase in the incidence of surgical indications for neoplasia cases. Focusing on closely monitoring individuals with longterm UC for neoplasms is necessary.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Background: Recent guidelines about preventing surgical site infections (SSIs) recommend against the administration of prophylactic antibiotics after surgery. However, many colorectal surgeons still prefer prolonged use of prophylactic antibiotics. While minimally invasive surgery (MIS) has become the standard for colorectal cancer surgery, there were few studies about proper dose of prophylactic antibiotics in minimally invasive colorectal surgery. Methods: This is a retrospective study. All patients underwent elective colorectal cancer surgery using MIS. Intravenous cefotetan was administered as a prophylactic antibiotic.Two groups were classified according to the dose of prophylactic antibiotics: a group using a single dose preoperatively (single-dose group) and a group using a preoperative single dose plus additional doses within 24 hours after surgery (multiple-dose group). The SSI rates between the two groups were compared before and after propensity score matching (PSM).Risk factors of SSIs were assessed using univariate and multivariable analysis. Results: There were 902 patients in the single-dose group and 330 patients in the multipledose group. After PSM, 320 patients were included in each group. There were no differences in baseline characteristics and surgical outcomes except the length of hospital stay. SSI rates were not different between the two groups before and after PSM (before 2.0% vs. 2.1%, P = 0.890; after 0.9% vs. 1.9%, P = 0.505). In multivariable analysis, American Society of Anesthesiologists class 3, rectal surgery, intraoperative transfusion, and larger tumor size were identified as independent factors associated with SSI incidence. Conclusion A single preoperative dose of prophylactic antibiotics may be sufficient to prevent SSIs in elective MIS for colorectal cancer.

Purpose: This study aimed to identify clinical and radiologic characteristics that could predict response to atezolizumab-bevacizumab combination therapy in patients with advanced hepatocellular carcinoma (HCC). Materials and Methods: This single-center retrospective study included 108 advanced HCC patients with intrahepatic lesions who were treated with atezolizumab-bevacizumab. Two radiologists independently analyzed imaging characteristics of the index tumor on pretreatment computed tomography. Predictive factors associated with progressive disease (PD) at the best response based on Response Evaluation Criteria in Solid Tumors, ver. 1.1 were evaluated using logistic regression analysis. Progression-free survival (PFS) was estimated by the Kaplan-Meier method and compared with the log-rank test. Results: Of 108 patients with a median PFS of 15 weeks, 40 (37.0%) had PD during treatment. Factors associated with PD included the presence of extrahepatic metastases (adjusted odds ratio [aOR], 4.13; 95% confidence interval [CI], 1.19 to 14.35; p=0.03), the infiltrative appearance of the tumor (aOR, 3.07; 95% CI, 1.05 to 8.93; p=0.04), and the absence of arterial-phase hyperenhancement (APHE) (aOR, 6.34; 95% CI, 2.18 to 18.47; p < 0.001). Patients with two or more of these factors had a PD of 66.7% and a median PFS of 8 weeks, indicating a significantly worse outcome compared to the patients with one or no of these factors. Conclusion In patients with advanced HCC treated with atezolizumab-bevacizumab treatment, the absence of APHE, infiltrative appearance of the intrahepatic tumor, and presence of extrahepatic metastases were associated with poor response and survival. Evaluation of early response may be necessary in patients with these factors.

Background: There is a need to update the cardiovascular (CV) Sequential Organ Failure Assessment (SOFA) score to reflect the current practice in sepsis. We previously proposed the modified CV SOFA score from data on blood pressure, norepinephrine equivalent dose, and lactate as gathered from emergency departments. In this study, we externally validated the modified CV SOFA score in multicenter intensive care unit (ICU) patients. Methods: A multicenter retrospective observational study was conducted on ICU patients at six hospitals in Korea. We included adult patients with sepsis who were admitted to ICUs. We compared the prognostic performance of the modified CV/total SOFA score and the original CV/total SOFA score in predicting 28-day mortality. Discrimination and calibration were evaluated using the area under the receiver operating characteristic curve (AUROC) and the calibration curve, respectively. Results: We analyzed 1,015 ICU patients with sepsis. In overall patients, the 28-day mortality rate was 31.2%. The predictive validity of the modified CV SOFA (AUROC, 0.712; 95% confidence interval [CI], 0.677–0.746; P < 0.001) was significantly higher than that of the original CV SOFA (AUROC, 0.644; 95% CI, 0.611–0.677). The predictive validity of modified total SOFA score for 28-day mortality was significantly higher than that of the original total SOFA (AUROC, 0.747 vs. 0.730; 95% CI, 0.715–0.779; P = 0.002). The calibration curve of the original CV SOFA for 28-day mortality showed poor calibration. In contrast, the calibration curve of the modified CV SOFA for 28-day mortality showed good calibration. Conclusion In patients with sepsis in the ICU, the modified SOFA score performed better than the original SOFA score in predicting 28-day mortality.

Purpose: Circulating tumor DNA (ctDNA) is emerging as a valuable non-invasive tool to identify tumor heterogeneity and tumor burden. This study investigated ctDNA dynamics in metastatic colorectal cancer patients treated with regorafenib. Materials and Methods: In this prospective biomarker study, plasma cell-free DNA (cfDNA) samples obtained at baseline, at the first response evaluation after 2 cycles of treatment, and at the time of progressive disease were sequenced using a targeted next-generation sequencing platform which included 106 genes. Results: A total of 285 blood samples from 110 patients were analyzed. Higher baseline cfDNA concentration was associated with worse progression-free survival (PFS) and overall survival (OS). After 2 cycles of treatment, variant allele frequency (VAF) in the majority of ctDNA mutations decreased with a mean relative change of –31.6%. Decreases in the VAF of TP53, APC, TCF7L2, and ROS1 after 2 cycles of regorafenib were associated with longer PFS. We used the sum of VAF at each time point as a surrogate for the overall ctDNA burden. A reduction in sum (VAF) of ≥ 50% after 2 cycles was associated with longer PFS (6.1 vs. 2.7 months, p=0.002), OS (11.3 vs. 5.9 months, p=0.001), and higher disease control rate (86.3% vs. 51.1%, p < 0.001). VAF of the majority of the ctDNA mutations increased at the time of disease progression, and VAF of BRAF increased markedly. Conclusion Reduction in ctDNA burden as estimated by sum (VAF) could be used to predict treatment outcome of regorafenib.