Background: s/Aims: Hepatocellular carcinoma (HCC) is the sixth most common cancer and second leading cause of cancer-related deaths in South Korea. This study evaluated the characteristics of Korean patients newly diagnosed with HCC in 2016-2018. Methods: Data from the Korean Primary Liver Cancer Registry (KPLCR), a representative database of patients newly diagnosed with HCC in South Korea, were analyzed. This study investigated 4,462 patients with HCC registered in the KPLCR in 2016-2018. Results: The median patient age was 63 years (interquartile range, 55-72). 79.7% of patients were male. Hepatitis B infection was the most common underlying liver disease (54.5%). The Barcelona Clinic Liver Cancer (BCLC) staging system classified patients as follows: stage 0 (14.9%), A (28.8%), B (7.5%), C (39.0%), and D (9.8%). The median overall survival was 3.72 years (95% confidence interval, 3.47-4.14), with 1-, 3-, and 5-year overall survival rates of 71.3%, 54.1%, and 44.3%, respectively. In 2016-2018, there was a significant shift toward BCLC stage 0-A and Child-Turcotte-Pugh liver function class A (P<0.05), although survival rates did not differ by diagnosis year. In the treatment group (n=4,389), the most common initial treatments were transarterial therapy (31.7%), surgical resection (24.9%), best supportive care (18.9%), and local ablation therapy (10.5%). Conclusions Between 2016 and 2018, HCC tended to be diagnosed at earlier stages, with better liver function in later years. However, since approximately half of the patients remained diagnosed at an advanced stage, more rigorous and optimized HCC screening strategies should be implemented.

Irritable bowel syndrome (IBS) is a chronic, disabling, and functional bowel disorder that significantly affects social functioning and reduces quality of life and increases social costs. The Korean Society of Neurogastroenterology and Motility published clinical practice guidelines on the management of IBS based on a systematic review of the literature in 2017, and planned to revise these guidelines in light of new evidence on the pathophysiology, diagnosis, and management of IBS. The current revised version of the guidelines is consistent with the previous version and targets adults diagnosed with or suspected of having IBS. These guidelines were developed using a combination of de novo and adaptation methods, with analyses of existing guidelines and discussions within the committee, leading to the identification of key clinical questions. Finally, the guidelines consisted of 22 recommendations, including 3 concerning the definition and risk factors of IBS, 4 regarding diagnostic modalities and strategies, 2 regarding general management, and 13 regarding medical treatment. For each statement, the advantages, disadvantages, and precautions were thoroughly detailed. The modified Delphi method was used to achieve expert consensus to adopt the core recommendations of the guidelines. These guidelines serve as a reference for clinicians (including primary care physicians, general healthcare providers, medical students, residents, and other healthcare professionals) and patients, helping them to make informed decisions regarding IBS management.

Background: Primary Merkel cell carcinoma of the salivary gland is currently not listed in the World Health Organization classification. However, cases of Merkel cell type neuroendocrine carcinomas of the salivary gland with perinuclear cytokeratin 20 positivity have been intermittently reported. We here investigated the clinicopathologic features of additional cases. Methods: Data of four cases of Merkel cell type small cell neuroendocrine carcinoma of the salivary gland were retrieved. To confirm the tumors’ primary nature, clinical records and pathologic materials were reviewed. Optimal immunohistochemical staining was performed to support the diagnosis. Results: All tumors were located in the parotid gland. Possibilities of metastasis were excluded in all cases through a meticulous clinicopathological review. Tumor histology was consistent with the diagnosis of small cell neuroendocrine carcinoma. Tumors’ immunohistochemical phenotypes were consistent with Merkel cell carcinoma, including Merkel cell polyomavirus large T antigen positivity in two of the four cases. Conclusions Merkel cell carcinomas can originate in salivary glands and are partly associated with Merkel cell polyomavirus infection as in cutaneous Merkel cell carcinomas.

Background and Objectives: The Korean Organ Transplant Registry (KOTRY) provided data for this third official report on adult heart transplantation (HT), including information from 709 recipients. Methods: Data from HTs performed at seven major centers in Korea between March 2014 and December 2020 were analyzed, focusing on immunosuppression, acute rejection, cardiac allograft vasculopathy (CAV), post-transplant survival, and mechanical circulatory support (MCS) usage. Results: The median ages of the recipients and donors were 56.0 and 43.0 years, respectively.Cardiomyopathy and ischemic heart disease were the most common preceding conditions for HT. A significant portion of patients underwent HT at waiting list status 1 and 0. In the multivariate analysis, a predicted heart mass mismatch was associated with a higher risk of 1-year mortality. Patients over 70 years old had a significantly increased risk of 6-year mortality. The risk of CAV was higher for male donors and donors older than 45 years. Acute rejection was more likely in patients with panel reactive antibody levels above 80%, while statin use was associated with a reduced risk. The employment of left ventricular assist device as a bridge to transplantation increased from 2.17% to 22.4%. Pre-transplant extra-corporeal membrane oxygenation was associated with worse post-transplant survival. Conclusions In this third KOTRY report, we analyzed changes in the characteristics of adult HT recipients and donors and their impact on post-transplant outcomes. The most notable discovery was the increased use of MCS before HT and their impact on post-transplant outcomes.

Purpose: Anorectal fistulas present a treatment challenge, with conventional surgical methods potentially resulting in complications such as fecal incontinence. To improve patient outcomes, more effective and minimally invasive therapies are critically needed. In this study, an optimal porcine model for the creation of anorectal fistulas was developed and used to evaluate the efficacy of radiofrequency ablation (RFA) therapy. Methods: Two distinct but related experiments were conducted. In the first experiment, a reliable and standardized porcine anorectal fistula model was developed. In the second, the healing process was assessed, and outcomes were compared between the RFA-treated group and the control group using the established porcine model. Results: The results indicated that a 3.5-cm fistula tract length and a 14-day evaluation period following seton removal are optimal for the porcine anorectal fistula model. In the second experiment, the RFA group tended to exhibit better outcomes regarding fistula closure, although the differences were not statistically significant. Histopathologically, no significant difference in inflammation grade was observed between groups; however, scar tissue was more predominant in the RFA group. Conclusion The findings suggest that RFA therapy may offer potential benefits in the treatment of anorectal fistulas, as demonstrated using a porcine model. To validate these results and explore the mechanisms of action underlying RFA therapy for anorectal fistulas, further research involving larger sample sizes and a more robust study design is required.

Purpose: Anorectal fistulas present a treatment challenge, with conventional surgical methods potentially resulting in complications such as fecal incontinence. To improve patient outcomes, more effective and minimally invasive therapies are critically needed. In this study, an optimal porcine model for the creation of anorectal fistulas was developed and used to evaluate the efficacy of radiofrequency ablation (RFA) therapy. Methods: Two distinct but related experiments were conducted. In the first experiment, a reliable and standardized porcine anorectal fistula model was developed. In the second, the healing process was assessed, and outcomes were compared between the RFA-treated group and the control group using the established porcine model. Results: The results indicated that a 3.5-cm fistula tract length and a 14-day evaluation period following seton removal are optimal for the porcine anorectal fistula model. In the second experiment, the RFA group tended to exhibit better outcomes regarding fistula closure, although the differences were not statistically significant. Histopathologically, no significant difference in inflammation grade was observed between groups; however, scar tissue was more predominant in the RFA group. Conclusion The findings suggest that RFA therapy may offer potential benefits in the treatment of anorectal fistulas, as demonstrated using a porcine model. To validate these results and explore the mechanisms of action underlying RFA therapy for anorectal fistulas, further research involving larger sample sizes and a more robust study design is required.

Extracellular vesicles (EVs) are lipid bilayer-enclosed particles that contain diverse molecular components, such as proteins, nucleic acids, and lipids. EVs reflect the state of their cell of origin in intercellular communication. Such characteristics of EVs demonstrate their potential as biomarkers and therapeutic agents in basic and translational research. Research on EV biology and applications has progressed significantly. However, challenges remain in translating their potential into clinical applications because of issues in nomenclature, the separation of EVs from nonvesicular extracellular particles, and methods for characterization and functional analysis. The International Society for Extracellular Vesicles addresses the current standards and challenges in this rapidly evolving field through periodical updates of its Minimal Information for Studies of Extracellular Vesicles (MISEV), which was published in 2014 and revised in 2018. The latest revision, MISEV2023, provides an updated overview of the current methodologies, detailing their strengths and limitations in EV production, separation, and characterization from various sources, including cell cultures, body fluids, and solid tissues. In this review, we summarize the fundamental principles of EV research by referencing the guidelines on EVs published by the Ministry of Food and Drug Safety of the Republic of Korea. Furthermore, we elaborate on the key aspects of MISEV2023, providing information for domestic EV researchers in selecting or developing optimal research methodologies according to their specific objectives and applications.