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.

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.

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.

When planning oral rehabilitation for maxillary edentulous patients, fixed prosthetic restoration using implants, complete denture restoration or overdentures using implants can be considered as treatment methods. In the case of complete denture restoration, it does not require additional surgery and is relatively economical. In the case of implant-supported fixed prostheses, the functional part is generally superior to that of complete denture restoration, but there are cases in which implant placement is clinically difficult. Recently in consideration of the patient’s needs and the condition of the remaining alveolar bone, after partial implant placement, a method of restoring with a removable partial denture using implant-supported surveyed crown is also being attempted. This case is a case of performing a removable partial denture restoration using implant-supported surveyed crown in the anterior maxilla, and showing satisfactory esthetic and functional results.

Purpose: To determine the effectiveness of salvage radiation therapy (RT) in patients with locoregional recurrence (LRR) following initial curative resection of non-small cell lung cancer (NSCLC) and identify the prognostic factors affecting survival. Materials and Methods: Between January 2009 and January 2019, 54 patients with LRR after NSCLC surgery were treated with salvage RT (83.3%) or concurrent chemoradiation therapy (16.7%). Twenty-three (42.6%), 21 (38.9%), and 10 (18.5%) patients had local, regional, and both recurrences, respectively. The median RT dose was 66 Gy (range, 37.5 to 70 Gy). The radiation target volume included recurrent lesions with or without regional lymphatics depending on the location and recurrence type. Results: The median follow-up time from the start of RT was 28.3 months (range, 2.4 to 112.4 months) and disease-free interval (DFI) from surgery to recurrence was 21.0 months (range, 0.5 to 92.3 months). Tumor response after RT was complete response, partial response, stable disease, and progressive disease in 17, 29, 5, and 3 patients, respectively. The rates of freedom from local progression at 1 and 2 years were 77.2% and 66.0%, respectively. The median survival duration after RT was 24.8 months, and the 2-year overall survival (OS) rate was 51.1%. On univariate analysis, initial stage, recurrence site, DFI, and tumor response after RT were significant prognostic factors for OS. DFI ≥12 months and tumor response after RT were statistically significant factors on multivariate Cox analysis for OS. Conclusion Our results demonstrated the effectiveness of salvage RT for LRR of NSCLC following curative surgery.

Background/Aims: To examine the prevalence and clinical characteristics of apparent treatment-resistant hypertension among ambulatory hypertensive patients. Methods: We enrolled adult ambulatory hypertensive patients at 13 well-qualified general hospitals in Korea from January to June 2012. Apparent resistant hypertension was defined as an elevated blood pressure > 140/90 mmHg with the use of three antihypertensive agents, including diuretics, or ≥ 4 antihypertensives, regardless of the blood pressure. Controlled hypertension was defined as a blood pressure within the target using three antihypertensives, including diuretics. Results: Among 16,915 hypertensive patients, 1,172 (6.9%) had controlled hypertension, and 1,514 (8.9%) had apparent treatment-resistant hypertension. Patients with apparent treatment-resistant hypertension had an earlier onset of hypertension (56.8 years vs. 58.8 years, p = 0.007) and higher body mass index (26.3 kg/m2 vs. 24.9 kg/m2, p < 0.001) than those with controlled hypertension. Drug compliance did not differ between groups. In the multivariable analysis, earlier onset of hypertension (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97 to 0.99; p < 0.001) and the presence of comorbidities (OR, 2.06; 95% CI, 1.27 to 3.35; p < 0.001), such as diabetes mellitus, ischemic heart disease, heart failure, and chronic kidney disease, were independent predictors. Among the patients with apparent treatment-resistant hypertension, only 5.2% were receiving ≥ 2 antihypertensives at maximally tolerated doses. Conclusions Apparent treatment-resistant hypertension prevalence is 8.9% among ambulatory hypertensive patients in Korea. An earlier onset of hypertension and the presence of comorbidities are independent predictors. Optimization of medical treatment may reduce the rate of apparent treatment-resistant hypertension.

Purpose: To determine the effectiveness of salvage radiation therapy (RT) in patients with locoregional recurrence (LRR) following initial curative resection of non-small cell lung cancer (NSCLC) and identify the prognostic factors affecting survival. Materials and Methods: Between January 2009 and January 2019, 54 patients with LRR after NSCLC surgery were treated with salvage RT (83.3%) or concurrent chemoradiation therapy (16.7%). Twenty-three (42.6%), 21 (38.9%), and 10 (18.5%) patients had local, regional, and both recurrences, respectively. The median RT dose was 66 Gy (range, 37.5 to 70 Gy). The radiation target volume included recurrent lesions with or without regional lymphatics depending on the location and recurrence type. Results: The median follow-up time from the start of RT was 28.3 months (range, 2.4 to 112.4 months) and disease-free interval (DFI) from surgery to recurrence was 21.0 months (range, 0.5 to 92.3 months). Tumor response after RT was complete response, partial response, stable disease, and progressive disease in 17, 29, 5, and 3 patients, respectively. The rates of freedom from local progression at 1 and 2 years were 77.2% and 66.0%, respectively. The median survival duration after RT was 24.8 months, and the 2-year overall survival (OS) rate was 51.1%. On univariate analysis, initial stage, recurrence site, DFI, and tumor response after RT were significant prognostic factors for OS. DFI ≥12 months and tumor response after RT were statistically significant factors on multivariate Cox analysis for OS. Conclusion Our results demonstrated the effectiveness of salvage RT for LRR of NSCLC following curative surgery.

Background/Aims: To examine the prevalence and clinical characteristics of apparent treatment-resistant hypertension among ambulatory hypertensive patients. Methods: We enrolled adult ambulatory hypertensive patients at 13 well-qualified general hospitals in Korea from January to June 2012. Apparent resistant hypertension was defined as an elevated blood pressure > 140/90 mmHg with the use of three antihypertensive agents, including diuretics, or ≥ 4 antihypertensives, regardless of the blood pressure. Controlled hypertension was defined as a blood pressure within the target using three antihypertensives, including diuretics. Results: Among 16,915 hypertensive patients, 1,172 (6.9%) had controlled hypertension, and 1,514 (8.9%) had apparent treatment-resistant hypertension. Patients with apparent treatment-resistant hypertension had an earlier onset of hypertension (56.8 years vs. 58.8 years, p = 0.007) and higher body mass index (26.3 kg/m2 vs. 24.9 kg/m2, p < 0.001) than those with controlled hypertension. Drug compliance did not differ between groups. In the multivariable analysis, earlier onset of hypertension (odds ratio [OR], 0.98; 95% confidence interval [CI], 0.97 to 0.99; p < 0.001) and the presence of comorbidities (OR, 2.06; 95% CI, 1.27 to 3.35; p < 0.001), such as diabetes mellitus, ischemic heart disease, heart failure, and chronic kidney disease, were independent predictors. Among the patients with apparent treatment-resistant hypertension, only 5.2% were receiving ≥ 2 antihypertensives at maximally tolerated doses. Conclusions Apparent treatment-resistant hypertension prevalence is 8.9% among ambulatory hypertensive patients in Korea. An earlier onset of hypertension and the presence of comorbidities are independent predictors. Optimization of medical treatment may reduce the rate of apparent treatment-resistant hypertension.

BACKGROUND AND OBJECTIVES: Although complete revascularization is known superior to incomplete revascularization in ST elevation myocardial infarction (STEMI) patients with multi-vessel coronary artery disease (MVCD), there are no definite instructions on the optimal timing of non-culprit lesions percutaneous coronary intervention (PCI). We compared 1-year clinical outcomes between 2 different complete multi-vessel revascularization strategies.METHODS: From the Korea Acute Myocardial Infarction Registry-National Institute of Health, 606 patients with STEMI and MVCD who underwent complete revascularization were enrolled from November 2011 to December 2015. The patients were assigned to multi-vessel single-staged PCI (SS PCI) group (n=254) or multi-vessel multi-staged PCI (MS PCI) group (n=352). Propensity score matched 1-year clinical outcomes were compared between the groups.RESULTS: At one year, MS PCI showed a significantly lower rate of all-cause mortality (hazard ratio [HR], 0.42; 95% confidential interval [CI], 0.19–0.92; p=0.030) compared with SS PCI. In subgroup analysis, all-cause mortality increased in SS PCI with cardiogenic shock (HR, 4.60; 95% CI, 1.54–13.77; p=0.006), age ≥65 years (HR, 4.00; 95% CI, 1.67–9.58, p=0.002), Killip class III/IV (HR, 7.32; 95% CI, 1.68–31.87; p=0.008), and creatinine clearance ≤60 mL/min (HR, 2.81; 95% CI, 1.10–7.18; p=0.031). After propensity score-matching, MS PCI showed a significantly lower risk of major adverse cardiovascular event than SS PCI.CONCLUSIONS: SS PCI was associated with worse clinical outcomes compared with MS PCI. MS PCI for non-infarct-related artery could be a better option for patients with STEMI and MVCD, especially high-risk patients.
Arteries ; Coronary Artery Disease ; Coronary Vessels ; Creatinine ; Humans ; Korea ; Mortality ; Myocardial Infarction ; Myocardial Revascularization ; Percutaneous Coronary Intervention ; Propensity Score ; Shock, Cardiogenic

BACKGROUND AND OBJECTIVES: Although complete revascularization is known superior to incomplete revascularization in ST elevation myocardial infarction (STEMI) patients with multi-vessel coronary artery disease (MVCD), there are no definite instructions on the optimal timing of non-culprit lesions percutaneous coronary intervention (PCI). We compared 1-year clinical outcomes between 2 different complete multi-vessel revascularization strategies. METHODS: From the Korea Acute Myocardial Infarction Registry-National Institute of Health, 606 patients with STEMI and MVCD who underwent complete revascularization were enrolled from November 2011 to December 2015. The patients were assigned to multi-vessel single-staged PCI (SS PCI) group (n=254) or multi-vessel multi-staged PCI (MS PCI) group (n=352). Propensity score matched 1-year clinical outcomes were compared between the groups. RESULTS: At one year, MS PCI showed a significantly lower rate of all-cause mortality (hazard ratio [HR], 0.42; 95% confidential interval [CI], 0.19–0.92; p=0.030) compared with SS PCI. In subgroup analysis, all-cause mortality increased in SS PCI with cardiogenic shock (HR, 4.60; 95% CI, 1.54–13.77; p=0.006), age ≥65 years (HR, 4.00; 95% CI, 1.67–9.58, p=0.002), Killip class III/IV (HR, 7.32; 95% CI, 1.68–31.87; p=0.008), and creatinine clearance ≤60 mL/min (HR, 2.81; 95% CI, 1.10–7.18; p=0.031). After propensity score-matching, MS PCI showed a significantly lower risk of major adverse cardiovascular event than SS PCI. CONCLUSIONS SS PCI was associated with worse clinical outcomes compared with MS PCI. MS PCI for non-infarct-related artery could be a better option for patients with STEMI and MVCD, especially high-risk patients.