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/Aims: Daratumumab has shown an encouraging antitumor effect in patients with multiple myeloma (MM), and was known to alter the immune properties by off-targeting immunosuppressive cells. Here, we aimed to evaluate the change in absolute lymphocyte count (ALC) as a surrogate marker for predicting survival outcomes of patients treated with daratumumab. Methods: Between 2018 and 2021, the medical records of patients with relapsed/refractory MM (RRMM) treated with daratumumab monotherapy at 10 centers in South Korea were reviewed. We collected the ALC data at pre-infusion (D0), day 2 after the first infusion (D2), and prior to the third cycle of daratumumab therapy (D56). Results: Fifty patients who were administered at least two cycles of daratumumab were included. Overall response rate was 54.0% after two cycles of daratumumab treatment. On D2, almost all patients experienced a marked reduction in ALC. However, an increase in ALC on D56 (ALCD56) was observed in patients with non-progressive disease, whereas failure of ALC recovery was noted in those with progressive disease. Patients with ALCD56 > 700/μL (n = 39, 78.0%) had prolonged progression- free survival (PFS) and overall survival (OS) than those with ALCD56 ≤ 700/μL (median PFS: 5.8 months vs. 2.6 months, p = 0.025; median OS: 24.1 months vs. 6.1 months, p = 0.004). In addition, ALCD56 >700/μL was a significant favorable prognostic factor for PFS (hazard ratio [HR], 0.22; p = 0.003) and OS (HR, 0.23; p = 0.012). Conclusions Increase in ALC during daratumumab treatment was significantly associated with prolonged survival outcomes in patients with RRMM. The ALC value can predict clinical outcomes in patients treated with daratumumab.

Percutaneous transthoracic needle biopsy (PTNB) is one of the essential diagnostic procedures for pulmonary lesions. Its role is increasing in the era of CT screening for lung cancer and precision medicine. The Korean Society of Thoracic Radiology developed the first evidence-based clinical guideline for PTNB in Korea by adapting pre-existing guidelines. The guideline provides 39 recommendations for the following four main domains of 12 key questions: the indications for PTNB, pre-procedural evaluation, procedural technique of PTNB and its accuracy, and management of post-biopsy complications. We hope that these recommendations can improve the diagnostic accuracy and safety of PTNB in clinical practice and promote standardization of the procedure nationwide.

Agaricus bisporus, commonly known as the button mushroom, is widely cultivated throughout the world. To breed new strains with more desirable traits and improved adaptability, diverse germplasm, including wild accessions, is a valuable genetic resource. To better understand the genetic diversity available in A. bisporus and identify previously unknown diversity within accessions, a phylogenetic analysis of 360 Agaricus spp. accessions using single-nucleotide polymorphism genotyping was performed. Genetic relationships were compared using principal coordinate analysis (PCoA) among accessions with known origins and accessions with limited collection data. The accessions clustered into four groups based on the PCoA with regard to genetic relationships. A subset of 67 strains, which comprised a core collection where repetitive and uninformative accessions were not included, clustered into 7 groups following analysis. Two of the 170 accessions with limited collection data were identified as wild germplasm. The core collection allowed for the accurate analysis of A. bisporus genetic relationships, and accessions with an unknown pedigree were effectively grouped, allowing for origin identification, by PCoA analysis in this study.

Background/Aims: Although balloon-assisted enteroscopy (BAE) enables endoscopic visualization of small bowel (SB) involvement in Crohn’s disease (CD), there is no data on the changes in outcomes over time. We therefore investigated the changes in BAE use on CD patients over different time periods in terms of its role and clinical outcomes. Methods: We used a multicenter enteroscopy database to identify CD patients with SB involvement who underwent BAE (131 procedures, 116 patients). We compared BAE-related factors and outcomes between the first period (70 procedures, 60 patients) and the second period (61procedures, 56 patients). The specific cutoff point for dividing the two periods was 2007, when BAE guidelines were introduced. Results: Initial diagnosis of SB involvement in CD was the most common indication for BAE during each period (50.0% vs 31.1%, p=0.034). The largest change was in the number of BAE uses for stricture evaluation and/or treatment, which increased significantly in the latter period (2.9% vs 21.3%, p=0.002). The diagnostic yield in patients with suspected CD was 90.7% in the first period and 95.0% in the second (p=0.695). More endoscopic interventions were performed in the second period than in the first (5.1% vs 17.6%, p=0.041). Enteroscopic success rates were high throughout (100% in the first period vs 80.0% in the second period, p>0.999). In the first and second periods, therapeutic plans were adjusted in 62.7% and 61.4% of patients, respectively. Conclusions The overall clinical indications, outcomes, and effectiveness of BAE were constant over time in CD patients with SB involvement, with the exception that the frequency of enteroscopic intervention increased remarkably.

Background: To date, there has been no practical guidelines for the prescription of antiepileptic drugs (AEDs) in brain tumor patients in Korea. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for AED usage in brain tumors since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of the keywords. Results: The core contents are as follows. Prophylactic AED administration is not recommended in newly diagnosed brain tumor patients without previous seizure history. When AEDs are administered during peri/postoperative period, it may be tapered off according to the following recommendations. In seizure-naïve patients with no postoperative seizure, it is recommended to stop or reduce AED 1 week after surgery. In seizure-naïve patients with one early postoperative seizure (<1 week after surgery), it is advisable to maintain AED for at least 3 months before tapering. In seizure-naïve patients with ≥2 postoperative seizures or in patients with preoperative seizure history, it is recommended to maintain AEDs for more than 1 year. The possibility of drug interactions should be considered when selecting AEDs in brain tumor patients. Driving can be allowed in brain tumor patients when proven to be seizure-free for more than 1 year. Conclusion The KSNO suggests prescribing AEDs in patients with brain tumor based on the current guideline. This guideline will contribute to spreading evidence-based prescription of AEDs in brain tumor patients in Korea.

Background: There have been no guidelines for the management of adult patients with diffuse midline glioma (DMG), H3K27M-mutant in Korea since the 2016 revised WHO classification newly defined this disease entity. Thus, the Korean Society for Neuro-Oncology (KSNO), a multidisciplinary academic society, had begun preparing guidelines for DMG since 2019. Methods: The Working Group was composed of 27 multidisciplinary medical experts in Korea.References were identified through searches of PubMed, MEDLINE, EMBASE, and Cochrane CENTRAL using specific and sensitive keywords as well as combinations of keywords. As ‘diffuse midline glioma’ was recently defined, and there was no international guideline, trials and guidelines of ‘diffuse intrinsic pontine glioma’ or ‘brain stem glioma’ were thoroughly reviewed first. Results: The core contents are as follows. The DMG can be diagnosed when all of the following three criteria are satisfied: the presence of the H3K27M mutation, midline location, and infiltrating feature. Without identification of H3K27M mutation by diagnostic biopsy, DMG cannot be diagnosed. For the primary treatment, maximal safe resection should be considered for tumors when feasible. Radiotherapy is the primary option for tumors in case the total resection is not possible. A total dose of 54 Gy to 60 Gy with conventional fractionation prescribed at 1-2 cm plus gross tumor volume is recommended. Although no chemotherapy has proven to be effective in DMG, concurrent chemoradiotherapy (± maintenance chemotherapy) with temozolomide following WHO grade IV glioblastoma’s protocol is recommended. Conclusion The detection of H3K27M mutation is the most important diagnostic criteria for DMG. Combination of surgery (if amenable to surgery), radiotherapy, and chemotherapy based on comprehensive multidisciplinary discussion can be considered as the treatment options for DMG.