BACKGROUND: Programmed cell death ligand 1 (PD-L1) plays a major role in the immune responses of a variety of cancers. Recently, several studies revealed that PD-L1 is differently expressed in some cases of non-melanoma skin cancer. The expression of PD-L1 in cutaneous squamous cell carcinoma has not yet been described in Korea. OBJECTIVE: To investigate the expression of PD-L1 in cutaneous squamous cell carcinoma and its association with variable clinicopathological factors. METHODS: We performed immunohistochemical staining of 52 cutaneous cell carcinoma cases, including 28 high-risk cases and 24 low-risk cases. Cases were selected from patients who had visited the department of dermatology of our hospital from 2001 to 2017. The expression patterns were assessed using the H-score. Cases demonstrating at least 1+ of PD-L1 in more than 1% of tumor cells were considered positive. RESULTS: PD-L1 expression of tumor cells was 19.2% (10/52) for all cases, 0.0% (0/24) for the low-risk group, and 35.7% (10/28) for the high-risk group. PD-L1 positive cutaneous squamous cell carcinoma cases showed a significantly higher proportion of large tumors and tumors with deep invasion and a higher lymphatic metastasis rate when compared to PD-L1 negative cutaneous squamous cell carcinoma cases. CONCLUSION: Our study shows that cutaneous squamous cell carcinoma exhibits PD-L1 expression in 19.2% of cases. PD-L1 positive tumors are associated with high-risk cases of cutaneous squamous cell carcinoma, which may help guide the choice of therapeutic strategy.
Carcinoma, Squamous Cell* ; Cell Death ; Dermatology ; Epithelial Cells* ; Humans ; Korea ; Lymphatic Metastasis ; Neoplasm Metastasis* ; Skin Neoplasms

Background/Aims: The incidence of acute gastrointestinal bleeding (GIB) increases with the utilization of anticoagulant and nonsteroidal anti-inflammatory drugs (NSAIDs). This study aimed to compare the risk of GIB between anticoagulant and NSAIDs combotherapy and anticoagulant monotherapy in real-world practice. Methods: We investigated the relative risk of GIB in individuals newly prescribed anticoagulant and NSAIDs combination therapy and that in individuals newly prescribed anticoagulant monotherapy at three hospitals using “common data model.” Cox proportional hazard models and Kaplan-Meier estimation were employed for risk comparison after propensity score matching. Results: A comprehensive analysis of 2,951 matched pairs showed that patients who received anticoagulant and NSAIDs combousers exhibited a significantly higher risk of GIB than those who received anticoagulant monousers (hazard ratio [HR], 1.66; 95% confidence interval [CI], 1.30 to 2.12; p<0.001). The risk of GIB associated with anticoagulant and NSAIDs combination therapy was also significantly higher than that associated with anticoagulant monotherapy in patients aged >65 years (HR, 1.53; 95% CI, 1.15 to 2.03; p=0.003) and >75 years (HR, 1.89;95% CI, 1.23 to 2.90; p=0.003). We also found that the risk of GIB was significantly higher in the patients who received anticoagulant and NSAIDs combousers than that in patients who received anticoagulant monousers in both male (p=0.016) and female cohorts (p=0.010). Conclusions The risk of GIB is significantly higher in patients who receive anticoagulant and NSAIDs combotherapy than that in patients who receive anticoagulant monotherapy. In addition, the risk of GIB associated with anticoagulant and NSAIDs combotherapy was much higher in individuals aged >75 years. Therefore, physicians should be more aware of pay more attention to the risk of GIB when they prescribe anticoagulant and NSAIDs.

Background/Aims: Recent studies have shown an increased risk of lower gastrointestinal bleeding in patients who use both nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs). We analyzed the risk of lower gastrointestinal bleeding and compared this risk between NSAID+PPI users and NSAID-only users. Methods: In this retrospective, observational study, data from five hospitals were analyzed using a common data model to determine the risk of lower gastrointestinal bleeding and compare this risk between NSAID+PPI users (target cohort) and NSAID-only users (comparative cohort). Cox proportional hazard models and the Kaplan-Meier estimations were employed after extensive propensity score matching. Results: Among 24,530 individuals in the target cohort and 57,264 in the comparative cohort, 8,728 propensity score-matched pairs were analyzed. The risk of lower gastrointestinal bleeding was significantly higher in NSAID+PPI users than in NSAID-only users (hazard ratio [HR], 2.843;95% confidence interval [CI], 1.998 to 4.044; p<0.001). Similar findings were also noted in elderly patients >65 years (HR, 2.737), males (HR, 2.963), and females (HR, 3.221). However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users (HR, 2.057; 95% CI, 0.714 to 5.924; p=0.172). Conclusions The risk of lower gastrointestinal bleeding was higher in NSAID+PPI users than in NSAID-only users. However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users.

Background/Aims: Recent studies have shown an increased risk of lower gastrointestinal bleeding in patients who use both nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs). We analyzed the risk of lower gastrointestinal bleeding and compared this risk between NSAID+PPI users and NSAID-only users. Methods: In this retrospective, observational study, data from five hospitals were analyzed using a common data model to determine the risk of lower gastrointestinal bleeding and compare this risk between NSAID+PPI users (target cohort) and NSAID-only users (comparative cohort). Cox proportional hazard models and the Kaplan-Meier estimations were employed after extensive propensity score matching. Results: Among 24,530 individuals in the target cohort and 57,264 in the comparative cohort, 8,728 propensity score-matched pairs were analyzed. The risk of lower gastrointestinal bleeding was significantly higher in NSAID+PPI users than in NSAID-only users (hazard ratio [HR], 2.843;95% confidence interval [CI], 1.998 to 4.044; p<0.001). Similar findings were also noted in elderly patients >65 years (HR, 2.737), males (HR, 2.963), and females (HR, 3.221). However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users (HR, 2.057; 95% CI, 0.714 to 5.924; p=0.172). Conclusions The risk of lower gastrointestinal bleeding was higher in NSAID+PPI users than in NSAID-only users. However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users.

Background/Aims: Recent studies have shown an increased risk of lower gastrointestinal bleeding in patients who use both nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs). We analyzed the risk of lower gastrointestinal bleeding and compared this risk between NSAID+PPI users and NSAID-only users. Methods: In this retrospective, observational study, data from five hospitals were analyzed using a common data model to determine the risk of lower gastrointestinal bleeding and compare this risk between NSAID+PPI users (target cohort) and NSAID-only users (comparative cohort). Cox proportional hazard models and the Kaplan-Meier estimations were employed after extensive propensity score matching. Results: Among 24,530 individuals in the target cohort and 57,264 in the comparative cohort, 8,728 propensity score-matched pairs were analyzed. The risk of lower gastrointestinal bleeding was significantly higher in NSAID+PPI users than in NSAID-only users (hazard ratio [HR], 2.843;95% confidence interval [CI], 1.998 to 4.044; p<0.001). Similar findings were also noted in elderly patients >65 years (HR, 2.737), males (HR, 2.963), and females (HR, 3.221). However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users (HR, 2.057; 95% CI, 0.714 to 5.924; p=0.172). Conclusions The risk of lower gastrointestinal bleeding was higher in NSAID+PPI users than in NSAID-only users. However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users.

Background/Aims: Recent studies have shown an increased risk of lower gastrointestinal bleeding in patients who use both nonsteroidal anti-inflammatory drugs (NSAIDs) and proton pump inhibitors (PPIs). We analyzed the risk of lower gastrointestinal bleeding and compared this risk between NSAID+PPI users and NSAID-only users. Methods: In this retrospective, observational study, data from five hospitals were analyzed using a common data model to determine the risk of lower gastrointestinal bleeding and compare this risk between NSAID+PPI users (target cohort) and NSAID-only users (comparative cohort). Cox proportional hazard models and the Kaplan-Meier estimations were employed after extensive propensity score matching. Results: Among 24,530 individuals in the target cohort and 57,264 in the comparative cohort, 8,728 propensity score-matched pairs were analyzed. The risk of lower gastrointestinal bleeding was significantly higher in NSAID+PPI users than in NSAID-only users (hazard ratio [HR], 2.843;95% confidence interval [CI], 1.998 to 4.044; p<0.001). Similar findings were also noted in elderly patients >65 years (HR, 2.737), males (HR, 2.963), and females (HR, 3.221). However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users (HR, 2.057; 95% CI, 0.714 to 5.924; p=0.172). Conclusions The risk of lower gastrointestinal bleeding was higher in NSAID+PPI users than in NSAID-only users. However, the risk of lower gastrointestinal bleeding was comparable between NSAID+mucoprotective agent users and NSAID-only users.

Background/Aims: Utilization of low-volume preparation agents is crucial to improve patient willingness to undergo repeat colonoscopies. However, gastric safety data on preparation agents are limited. This study evaluated the acute gastropathy associated with bowel preparation agents. Methods: This retrospective study enrolled healthy subjects who underwent both esophagogastroduodenoscopy and colonoscopy screening. Baseline patient characteristics, bowel preparation success, acute gastropathy, and polyp and adenoma detection rates were evaluated for 1 L polyethylene glycol with ascorbic acid (1 L PEG/Asc) and oral sulfate tablet (OST) groups. Results: Comparison of the OST group (n=2,463) with the 1 L PEG/Asc group (n=2,060) revealed that the rates of successful cleansing and high-quality cleansing were similar between the two groups. Polyp and adenoma detection rates were significantly higher in the OST group than in the 1 L PEG/Asc group (p<0.001 and p=0.013), while the incidence of acute gastric mucosal lesion-like blood stain/clot, erosions at greater curvature side of antrum/body, multiple erosions, and overlying mucosal erythema or edema were all significantly higher in the OST group than in the 1 L PEG/Asc group (all p<0.001). Additionally, high and indeterminate probability scores of preparation agent-induced gastropathy (p=0.001) and mean Lanza scores were significantly higher in the OST group than in the 1 L PEG/Asc group (1.3 vs. 0.4, p<0.001). Conclusions Compared with 1 L PEG/Asc, OSTs were significantly associated with acute gastropathy during bowel preparation, thus requiring careful consideration from physicians for the simultaneous screening of EGD and colonoscopy.

Background/Aims: Non-time-sensitive gastrointestinal endoscopy was deferred because of the risk of exposure to coronavirus disease 2019 (COVID-19), but no population-based studies have quantified the adverse impact on gastrointestinal procedures. This study examined the impact of the COVID-19 pandemic on the performance of esophagogastroduodenoscopy (EGD), colonoscopy, ERCP, and abdominal ultrasonography (US) in South Korea. Methods: This nationwide, population-based study compared the claim data of EGD, colonoscopy, ERCP, and abdominal US in 2020 and 2021 (COVID-19 era) with those in 2019 (before the COVID-19 era). Results: During the first year (2020) of the COVID-19 pandemic, the annual claim data of EGD and colonoscopy were reduced by 6.3% and 6.9%, respectively, but those of ERCP and abdominal US were increased by 1.0% and 2.9%, compared to those in 2019. During the first surge (March and April 2020) of COVID-19, the monthly claim data of EGD, colonoscopy, ERCP, and abdominal US were reduced by 28.8%, 43.8%, 5.1%, and 21.6%, respectively, in March 2020, and also reduced by 17.2%, 32.8%, 4.4%, and 9.5%, respectively, in April 2020, compared to those in March and April 2019. During March and April 2020, the monthly claims of ERCP, compared with those in 2019, declined less significantly than those of EGD and colonoscopy (both p<0.001). Conclusions The claims of EGD and colonoscopy were reduced more significantly than those of ERCP and abdominal US during the COVID-19 pandemic because ERCPs are time-sensitive procedures and abdominal USs are non-aerosolized procedures.