Multiple myeloma (MM), a hematological malignancy, is characterized by malignant plasma cell proliferation in the bone marrow. Recent treatment advances have significantly improved patient outcomes associated with MM.In this study, we aimed to develop comprehensive, evidence-based guidelines for the diagnosis, prognosis, and treat‑ ment of MM. We identified 12 key clinical questions essential for MM management, guiding the extensive literature review and meta-analysis of the study. Our guidelines provide evidence-based recommendations by integrating patient preferences with survey data. These recommendations include current and emerging diagnostic tools, thera‑ peutic agents, and treatment strategies. By prioritizing a patient-centered approach and rigorous data analysis, these guidelines were developed to enhance MM management, both in Korea and globally.

Purpose: The cytotoxic T-lymphocyte-associated protein 4 (CTLA4) is involved in the progression of various cancers, but its biological roles in breast cancer (BRCA) remain unclear. Therefore, we performed a systematic multiomic analysis to expound on the prognostic value and underlying mechanism of CTLA4 in BRCA. Methods: We assessed the effect of CTLA4 expression on BRCA using a variety of bioinformatics platforms, including Oncomine, GEPIA, UALCAN, PrognoScan database, Kaplan-Meier plotter, and R2: Kaplan-Meier scanner. Results: CTLA4 was highly expressed in BRCA tumor tissue compared to normal tissue (P < 0.01). The CTLA4 messenger RNA levels in BRCA based on BRCA subtypes of Luminal, human epidermal growth factor receptor 2, and triple-negative BRCA were considerably higher than in normal tissues (P < 0.001). However, the overexpression of CTLA4 was associated with a better prognosis in BRCA (P < 0.001) and was correlated with clinicopathological characteristics including age, T stage, estrogen receptors, progesterone receptors, and prediction analysis of microarray 50 (P < 0.01). The infiltration of multiple immune cells was associated with increased CTLA4 expression in BRCA (P < 0.001). CTLA4 was highly enriched in antigen binding, immunoglobulin complexes, lymphocyte-mediated immunity, and cytokine-cytokine receptor interaction. Conclusion This study provides suggestive evidence of the prognostic role of CTLA4 in BRCA, which may be a therapeutic target for BRCA. Furthermore, CTLA4 may influence BRCA prognosis through antigen binding, immunoglobulin complexes, lymphocyte-mediated immunity, and cytokine-cytokine receptor interaction. These findings help us understand how CTLA4 plays a role in BRCA and set the stage for more research.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background: Inhibitory effects of denosumab on bone remodeling are reversible and disappear once treatment is discontinued. Herein, we examined whether and to what extent delayed denosumab administration is also associated with fracture risk using nation-wide data. Methods: The study cohort included women aged 45 to 89 years who were started on denosumab for osteoporosis between October 2017 and December 2019 using data from the Korean Health Insurance Review and Assessment service. Participants were stratified according to the time of their subsequent denosumab administration from the last denosumab administration, including those with within 30 days early dosing (ED30), within the planned time of 180–210 days (referent), within 30–90 days of delayed dosing (DD90), within 90–180 days of delayed dosing (DD180), and longer than 181 days of delayed dosing (DD181+). The primary outcome was the incidence of all clinical fractures. Results: A total of 149,199 participants included and 2,323 all clinical fractures (including 1,223 vertebral fractures) occurred. The incidence of all fractures was significantly higher in the DD90 compared to reference group (hazard ratio [HR], 1.2; 95% confidence interval [CI], 1.1 to 1.4). The risk of all fracture was even higher in the longer delayed DD180 group (HR, 1.9; 95% CI, 1.6 to 2.3) and DD181+ group (HR, 1.8; 95% CI, 1.5 to 2.2). Increased risks of fractures with delayed dosing were consistently observed for vertebral fractures. Conclusion Delayed denosumab dosing, even by 1 to 3 months, was significantly associated with increased fracture risk. Maintaining the correct dosing schedule should be emphasized when starting denosumab.

Background/Aims: We aimed to compare the effectiveness and safety of Janus kinase inhibitors (JAKi) vs. biologic disease- modifying antirheumatic drugs (bDMARD) in Korean patients with rheumatoid arthritis (RA) who had an inadequate response to conventional synthetic DMARDs. Methods: A quasi-experimental, multi-center, prospective, non-randomized study was conducted to compare response rates between JAKi and bDMARDs in patients with RA naïve to targeted therapy. An interim analysis was performed to estimate the proportion of patients achieving low disease activity (LDA) based on disease activity score (DAS)–28– erythroid sedimentation rate (ESR) (DAS28-ESR) at 24 weeks after treatment initiation and to evaluate the development of adverse events (AEs). Results: Among 506 patients enrolled from 17 institutions between April 2020 and August 2022, 346 (196 JAKi group and 150 bDMARD group) were included in the analysis. After 24 weeks of treatment, 49.0% of JAKi users and 48.7% of bDMARD users achieved LDA (p = 0.954). DAS28-ESR remission rates were also comparable between JAKi and bDMARD users (30.1% and 31.3%, respectively; p = 0.806). The frequency of AEs reported in the JAKi group was numerically higher than that in the bDMARDs group, but the frequencies of serious and severe AEs were comparable between the groups. Conclusions Our interim findings reveal JAKi have comparable effectiveness and safety to bDMARDs at 24 weeks after treatment initiation.

Gastric cancer is one of the most common cancers in Korea and the world. Since 2004, this is the 4th gastric cancer guideline published in Korea which is the revised version of previous evidence-based approach in 2018. Current guideline is a collaborative work of the interdisciplinary working group including experts in the field of gastric surgery, gastroenterology, endoscopy, medical oncology, abdominal radiology, pathology, nuclear medicine, radiation oncology and guideline development methodology. Total of 33 key questions were updated or proposed after a collaborative review by the working group and 40 statements were developed according to the systematic review using the MEDLINE, Embase, Cochrane Library and KoreaMed database. The level of evidence and the grading of recommendations were categorized according to the Grading of Recommendations, Assessment, Development and Evaluation proposition. Evidence level, benefit, harm, and clinical applicability was considered as the significant factors for recommendation. The working group reviewed recommendations and discussed for consensus. In the earlier part, general consideration discusses screening, diagnosis and staging of endoscopy, pathology, radiology, and nuclear medicine. Flowchart is depicted with statements which is supported by meta-analysis and references. Since clinical trial and systematic review was not suitable for postoperative oncologic and nutritional follow-up, working group agreed to conduct a nationwide survey investigating the clinical practice of all tertiary or general hospitals in Korea. The purpose of this survey was to provide baseline information on follow up. Herein we present a multidisciplinary-evidence based gastric cancer guideline.

Background: Left ventricular longitudinal strain is an emerging marker of ventricular systolic function. However, the prognostic value of apical four-chamber longitudinal strain after heart valve surgery in real-world clinical practice is uncertain. The authors investigated whether left ventricular apical four-chamber longitudinal strain measured in real-world practice is helpful for predicting postoperative outcomes in patients undergoing heart valve surgery. Methods: This observational cohort study was conducted in patients who underwent heart valve surgery between January 2014 and December 2018 at a tertiary hospital in South Korea. The exposure of interest was preoperative left ventricular apical four-chamber longitudinal strain. The primary outcome was postoperative all-cause mortality. Results: Among 1,773 study patients (median age, 63 years; female, 45.9%), 132 (7.4%) died during a median follow-up of 27.2 months. Preoperative left ventricular apical four-chamber longitudinal strain was significantly associated with all-cause mortality (adjusted hazard ratio, 0.94 per 1% increment in absolute value; 95% CI [0.90, 0.99], P = 0.022), whereas left ventricular ejection fraction (LVEF) was not significantly associated with all-cause mortality (adjusted hazard ratio: 1.01, 95% CI [0.99, 1.03], P = 0.222). Moreover, combining left ventricular apical four-chamber longitudinal strain to the LVEF and conventional prognostic factors enhance the prognostic model for all-cause mortality (P = 0.022). Conclusions In patients undergoing heart valve surgery without coronary artery disease, left ventricular apical four-chamber longitudinal strain measured in real-world clinical practice was independently associated with postoperative survival. Left ventricular longitudinal strain measurement may be helpful for outcome prediction after valve surgery.