Purpose: Postoperative complications following gastric cancer surgery significantly impact patient outcomes, yet standardized definitions for these events have not been consistently applied across institutions in Korea. This study aimed to develop a consensus-based, standardized complication classification system specific to gastrectomy for gastric cancer as part of the Korean Quality Improvement Platform in Surgery (K-QIPS) initiative. Methods: As part of K-QIPS, a dedicated task force team (TFT) was formed with surgical experts from fourteen high-volume hospitals across Korea. The TFT conducted ten formal meetings to review existing literature and international guidelines, and incorporated findings from randomized controlled trials. The final complication list was developed through expert consensus and structured into a standardized framework. A Data Entry Manual was created to support consistent data collection by surgical clinical reviewers. Results: The TFT defined specific postoperative complications following gastrectomy for gastric cancer, including anastomotic leakage, duodenal stump leakage, pancreatic fistula, intra-abdominal and luminal bleeding, delayed gastric emptying, and internal hernia. Notably, internal hernia was described in standardized form for the first time. General complications were developed first and overlapped in part with the gastric cancer-specific list. The task force also produced a Data Entry Manual that provides practical instructions to ensure consistency and accuracy in complication reporting. Conclusion This nationwide consensus initiative established the first standardized complication classification system for gastric cancer surgery in Korea. The proposed definitions and data entry system are expected to improve complication reporting, enable multicenter research, support surgical quality benchmarking, and ultimately enhance patient outcomes.

Background: MUTYH-associated polyposis is an autosomal recessive disorder associated with an increased lifetime risk of colorectal cancer and a moderately increased risk of ovarian, bladder, breast, and endometrial cancers. We analyzed the carrier frequency and estimated the incidence of MUTYH-associated polyposis in East Asian and Korean populations, for which limited data were previously available. Methods: We examined 125,748 exomes from the gnomAD database, including 9,197 East Asians, and additional data from 5,305 individuals in the Korean Variant Archive and 1,722 in the Korean Reference Genome Database. All MUTYH variants were interpreted according to the American College of Medical Genetics and Genomics and Association for Molecular Pathology guidelines and the Sequence Variant Interpretation guidelines from ClinGen. Results: The global carrier frequency of MUTYH-associated polyposis was 1.29%, with Europeans (non-Finnish) having the highest frequency of 1.86% and Ashkenazi Jews the lowest at 0.06%. East Asians and Koreans had a carrier frequency of 0.35% and 0.37% and an estimated incidence of 1 in 330,409 and 1 in 293,304 in Koreans, respectively, which were substantially lower than the global average of 1 in 24,160 and the European (nonFinnish) incidence of 1 in 11,520. Conclusions This was the first study to investigate the frequency of carriers of MUTYH-associated polyposis in East Asians, including specific subgroups, utilizing gnomAD and a Korean genome database. Our data provide valuable reference information for future investigations of MUTYH-associated polyposis to understand the genetic diversity and specific variants associated with this condition in East Asian populations.

With a rapidly aging population and increasing use of antiresorptive agents, medication-related osteonecrosis of the jaw (MRONJ) represents a growing clinical challenge worldwide. To address the need for tailored clinical guidance, a multidisciplinary task force was convened. Five Korean academic societies—the Korean Society for Bone and Mineral Research, the Korean Association of Oral and Maxillofacial Surgeons, the Korean Association of Maxillofacial Plastic and Reconstructive Surgeons, the Korean Society of Osteoporosis, and the Korean Endocrine Society—collaborated to develop this position statement. The consensus was formulated through comprehensive reviews of literature, combined with three rounds of formal surveys to consolidate expert opinion on controversial topics. This position paper provides evidence-based clinical guidelines for the prevention, diagnosis, and management of MRONJ tailored to the Korean healthcare environment. The diagnostic criteria affirm the standard definition but add a provision for diagnosis based on clinical or radiographic evidence of necrotic bone, even if the traditional 8-week timeframe has not been met. The committee advocates for retaining Stage 0 in the staging system to emphasize early detection and preventive intervention. Key recommendations include prescriptive, drug-specific guidelines for prophylactic drug holidays (e.g., a 2-month pause for oral bisphosphonates; timing surgery 3-4 months after the last denosumab injection) to minimize MRONJ risk from dental procedures. This statement also provides a clear framework for therapeutic drug holidays in established MRONJ, carefully balancing the need for jaw healing against systemic fracture risk. For treatment, this statement advocates for early and active surgical intervention across all MRONJ stages, supported by evidence of superior long-term outcomes compared to conservative management.This position statement offers a unique, evidence-based Korean clinical practice guideline for managing MRONJ. It is intended to standardize care, reduce clinical confusion, and ultimately improve patient outcomes by providing a clear framework for decision-making.

With a rapidly aging population and increasing use of antiresorptive agents, medication-related osteonecrosis of the jaw (MRONJ) represents a growing clinical challenge worldwide. To address the need for tailored clinical guidance, a multidisciplinary task force was convened. Five Korean academic societies—the Korean Society for Bone and Mineral Research, the Korean Association of Oral and Maxillofacial Surgeons, the Korean Society of Maxillofacial Plastic and Reconstructive Surgeons, the Korean Osteoporosis Society, and the Korean Endocrine Society—collaborated to develop this position statement. The consensus was formulated through comprehensive reviews of literature, combined with three rounds of formal surveys to consolidate expert opinion on controversial topics. This position paper provides evidence-based clinical guidelines for the prevention, diagnosis, and management of MRONJ tailored to the Korean healthcare environment. The diagnostic criteria affirm the standard definition but add a provision for diagnosis based on clinical or radiographic evidence of necrotic bone, even if the traditional 8-week timeframe has not been met. The committee advocates for retaining stage 0 in the staging system to emphasize early detection and preventive intervention. Key recommendations include prescriptive, drug-specific guidelines for prophylactic drug holidays (e.g., a 2-month pause for oral bisphosphonates; timing surgery 3 to 4 months after the last denosumab injection) to minimize MRONJ risk from dental procedures. This statement also provides a clear framework for therapeutic drug holidays in established MRONJ, carefully balancing the need for jaw healing against systemic fracture risk. For treatment, this statement advocates for early and active surgical intervention across all MRONJ stages, supported by evidence of superior long-term outcomes compared to conservative management. This position statement offers a unique, evidence-based Korean clinical practice guideline for managing MRONJ. It is intended to standardize care, reduce clinical confusion, and ultimately improve patient outcomes by providing a clear framework for decision-making.

Background: Adrenocortical carcinomas (ACCs) are rare tumors with aggressive but varied prognosis. Stage, Grade, Resection status, Age, Symptoms (S-GRAS) score, based on clinical and pathological factors, was found to best stratify the prognosis of European ACC patients. This study assessed the prognostic performance of modified S-GRAS (mS-GRAS) scores including modified grade (mG) by integrating mitotic counts into the Ki67 index (original grade), in Korean ACC patients. Methods: Patients who underwent surgery for ACC between January 1996 and December 2022 at three medical centers in Korea were retrospectively analyzed. mS-GRAS scores were calculated based on tumor stage, mG (Ki67 index or mitotic counts), resection status, age, and symptoms. Patients were divided into four groups (0–1, 2–3, 4–5, and 6–9 points) based on total mS-GRAS score. The associations of each variable and mS-GRAS score with recurrence and survival were evaluated using Cox regression analysis, Harrell’s concordance index (C-index), and the Kaplan–Meier method. Results: Data on mS-GRAS components were available for 114 of the 153 patients who underwent surgery for ACC. These 114 patients had recurrence and death rates of 61.4% and 48.2%, respectively. mS-GRAS score was a significantly better predictor of recurrence (C-index=0.829) and death (C-index=0.747) than each component (P<0.05), except for resection status. mS-GRAS scores correlated with shorter progression-free survival (P=8.34E-24) and overall survival (P=2.72E-13). Conclusion mS-GRAS scores showed better prognostic performance than tumor stage and grade in Asian patients who underwent surgery for ACC.

BACKGROUND: Liver biopsy for the diagnosis of non-alcoholic steatohepatitis (NASH) is limited by its inherent invasiveness and possible sampling errors. Some studies have shown that cytokeratin-18 (CK-18) concentrations may be useful in diagnosing NASH, but results across studies have been inconsistent. We aimed to identify the utility of CK-18 M30 concentrations as an alternative to liver biopsy for non-invasive identification of NASH. METHODS: Individual data were collected from 14 registry centers on patients with biopsy-proven non-alcoholic fatty liver disease (NAFLD), and in all patients, circulating CK-18 M30 levels were measured. Individuals with a NAFLD activity score (NAS) ≥5 with a score of ≥1 for each of steatosis, ballooning, and lobular inflammation were diagnosed as having definite NASH; individuals with a NAS ≤2 and no fibrosis were diagnosed as having non-alcoholic fatty liver (NAFL). RESULTS: A total of 2571 participants were screened, and 1008 (153 with NAFL and 855 with NASH) were finally enrolled. Median CK-18 M30 levels were higher in patients with NASH than in those with NAFL (mean difference 177 U/L; standardized mean difference [SMD]: 0.87 [0.69-1.04]). There was an interaction between CK-18 M30 levels and serum alanine aminotransferase, body mass index (BMI), and hypertension ( P  < 0.001, P  = 0.026 and P  = 0.049, respectively). CK-18 M30 levels were positively associated with histological NAS in most centers. The area under the receiver operating characteristics (AUROC) for NASH was 0.750 (95% confidence intervals: 0.714-0.787), and CK-18 M30 at Youden's index maximum was 275.7 U/L. Both sensitivity (55% [52%-59%]) and positive predictive value (59%) were not ideal. CONCLUSION This large multicenter registry study shows that CK-18 M30 measurement in isolation is of limited value for non-invasively diagnosing NASH.
Humans ; Non-alcoholic Fatty Liver Disease/diagnosis* ; Keratin-18 ; Biomarkers ; Biopsy ; Hepatocytes/pathology* ; Apoptosis ; Liver/pathology*

Objective:To investigate the classification of main pancreatic duct and treatment strategy after linear stapler closure of pancreatic neck in laparoscopic pancreaticoduodenectomy (LPD).Methods:The records of 51 consecutive patients with LPD who were treated by linear staple closure technique of pancreatic neck from February to December 2022 from Binzhou Second People′s Hospital, Shijingshan Campus, Beijing Chaoyang Hospital, Capital Medical University, Rizhao Hepatobiliary-Pancreatic-Splenic Surgery Research Institute, Chaoyang Central Hospital, Shandong Juxian People′s Hospital, Weihai Municipal Hospital, Binzhou Central Hospital, and Affiliated Hospital of Chifeng University were retrospectively reviewed. According to the visibility, position and diameter of the main pancreatic duct at the stump of the pancreas, the type of main pancreatic duct was divided into type I, type Ⅱ, type Ⅲa and type Ⅲb. The number of cases in each main pancreatic duct classification and the corresponding treatment strategies were examined.Results:A total of 51 cases of LPD were successfully completed. Of these patients, the males comprised 56.9%(29/51), and females comprised 43.1%(22/51), with age ranging from 31 to 88 years old. The type of the main pancreatic duct at the stump of the pancreas included 7 cases (13.7%) of type Ⅰ, 39 cases (76.5%) of type Ⅱ, 2 cases (3.9%) of type Ⅲa, and 3 cases (5.9%) of type Ⅲb. Corresponding treatment strategies were adopted according to different main pancreatic duct types, the main pancreatic duct was successfully found, and a support drainage tube was inserted.Conclusion:After linear stapler closure of pancreatic neck, corresponding treatment strategies should be adopted according to the classification of the main pancreatic duct, which would help to improve the success rate of finding the main pancreatic duct and placing a support drainage tube.

Purpose: Patient-derived tumor cells can be a powerful resource for studying pathophysiological mechanisms and developing robust strategies for precision medicine. However, establishing organoids from patient-derived cells is challenging because of limited access to tissue specimens. Therefore, we aimed to establish organoids from malignant ascites and pleural effusions. Materials and Methods: Ascitic or pleural fluid from pancreatic, gastric, and breast cancer patients was collected and concentrated to culture tumor cells ex vivo. Organoids were considered to be successfully cultured when maintained for five or more passages. Immunohistochemical staining was performed to compare the molecular features, and drug sensitivity was assayed to analyze the clinical responses of original patients. Results: We collected 70 fluid samples from 58 patients (pancreatic cancer, n=39; gastric cancer, n=21; and breast cancer, n=10). The overall success rate was 40%; however, it differed with types of malignancy, with pancreatic, gastric, and breast cancers showing 48.7%, 33.3%, and 20%, respectively. Cytopathological results significantly differed between successful and failed cases (p=0.014). Immunohistochemical staining of breast cancer organoids showed molecular features identical to those of tumor tissues. In drug sensitivity assays, pancreatic cancer organoids recapitulated the clinical responses of the original patients. Conclusion Tumor organoids established from malignant ascites or pleural effusion of pancreatic, gastric, and breast cancers reflect the molecular characteristics and drug sensitivity profiles. Our organoid platform could be used as a testbed for patients with pleural and peritoneal metastases to guide precision oncology and drug discovery.

Background: In non-small cell lung cancer (NSCLC), epidermal growth factor receptor (EGFR) mutation testing of tumor tissue should be conducted at diagnosis. Alternatively, circulating tumor DNA can be used to detect EGFR mutation. We compared the cost and clinical effect of three strategies according to the application of the EGFR test. Methods: Decision models were developed to compare the cost-effectiveness of tissue-only, tissue-first, and plasma-first diagnostic strategies as first- and second-line treatments for NSCLC from the perspective of the Korean national healthcare payer. Progression-free survival (PFS), overall survival (OS), and direct medical costs were assessed. A one-way sensitivity analysis was performed. Results: The plasma-first strategy correctly identified numerous patients in the first- and second-line treatments. This strategy also decreased the cost of biopsy procedures and complications. Compared with that when using the other two strategies, the plasma-first strategy increased PFS by 0.5 months. The plasma-first strategy increased OS by 0.9 and 1 month compared with that when using the tissue-only and tissue-first strategies, respectively. The plasma-first strategy was the least expensive first-line treatment but the most expensive second-line treatment. First-generation tyrosine kinase inhibitor and the detection rate of the T790M mutation in tissues were the most cost-influential factors. Conclusions The plasma-first strategy improved PFS and OS, allowing for a more accurate identification of candidates for targeted therapy for NSCLC and decreased biopsy- and complication-related costs.

Background: Not so many reports about the association between head and neck cancer (HNC) and oral health status related to periodontitis (OHS-P) has been published in different countries with different methods. So, there is a need for an extensive meta-analysis with the total articles published until 2020. Hence, this study aimed to estimate the association between HNC and OHS-P through a meta-analysis. Methods: Based on Preferred Reporting Items for Systematic Reviews and Meta Analyses guidelines, 22 studies were selected through PubMed and Cochrane Library databases. Metaanalysis using them was performed to evaluate the association. The risk of bias assessment using the Newcastle-Ottawa Scale (NOS) was applied to evaluate the quality of nonrandomized studies. Publication bias was evaluated by funnel plot and Egger's regression test. Results: Since heterogeneity was significant (I2 = 88%, P < 0.001), we adopted the random effect model for 22 studies. Those with bad OHS-P, compared to those with good OHS-P, were more likely to have the risk of HNC by 2.4 times (odds ratio [OR], 2.42; 95% confidence interval [CI], 1.88–3.13) for random effect model. The association included publication bias (Egger's regression, P value < 0.001). The association among five studies (I2 = 39%, P = 0.16) using alveolar bone loss (ABL) or clinical attachment level (CAL) for assessing periodontitis increased to OR of 3.85 (CI, 3.04–4.88) in the fixed effect model without publication bias (Egger's regression, P = 0.66). Moreover, the association was higher in 10 fair or good NOS studies (OR, 3.08) and in 7 Asian studies (OR, 2.68), which were from the fixed model without publication bias. Conclusion Our meta-analysis showed that bad OHS-P was associated with the risk of HNC.The association was stronger in studies using ABL or CAL for assessing periodontitis.