Background: Many studies have shown that Hashimoto’s thyroiditis (HT) acts as a protective factor in differentiated thyroid cancer (DTC), but little is known about its effects on mortality. Therefore, this study was performed to reveal the prognosis of HT on mortality in patients with DTC. Methods: This study included two types of research results: retrospective cohort study using the National Epidemiologic Survey of Thyroid cancer (NEST) in Korea and meta-analysis study with the NEST data and eight selected studies. Results: Of the 4,398 patients with DTC in NEST, 341 patients (7.8%) died during the median follow-up period of 15 years (interquartile range, 12.3 to 15.6). Of these, 91 deaths (2.1%) were related to DTC. HT was associated with a smaller tumor size and less aggressive DTC. In Cox regression analysis after adjusting for age and sex, patients with HT showed a significantly lower risk of all-cause death (hazard ratio [HR], 0.71; 95% confidence interval [CI], 0.52 to 0.96) and DTC-related death (HR, 0.33; 95% CI, 0.14 to 0.77). The analysis with inverse probability of treatment weight data adjusted for age, sex, and year of thyroid cancer registration showed similar association. The meta-analysis showed that patients with HT showed a lower risk of all-cause mortality (risk ratio [RR], 0.24; 95% CI, 0.13 to 0.47) and thyroid cancer-related mortality (RR, 0.23; 95% CI, 0.13 to 0.40) in comparison with patients without HT. Conclusion This study showed that DTC co-presenting with HT is associated with a low risk of advanced DTC and presents a low risk for all-cause and DTC-related death.

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.

Stem cells are the foundational cells for every organ and tissue in our body. Cell-based therapeutics using stem cells in regenerative medicine have received attracting attention as a possible treatment for various diseases caused by congenital defects. Stem cells such as induced pluripotent stem cells (iPSCs) as well as embryonic stem cells (ESCs), mesenchymal stem cells (MSCs), and neuroprogenitors stem cells (NSCs) have recently been studied in various ways as a cell-based therapeutic agent. When various stem cells are transplanted into a living body, they can differentiate and perform complex functions. For stem cell transplantation, it is essential to determine the suitability of the stem cell-based treatment by evaluating the origin of stem, the route of administration, In vivo bio-distribution, transplanted cell survival, function, and mobility. Currently, these various stem cells are being imaged In vivo through various molecular imaging methods. Various imaging modalities such as optical imaging, magnetic resonance imaging (MRI), ultrasound (US), positron emission tomography (PET), and single-photon emission computed tomography (SPECT) have been introduced for the application of various stem cell imaging. In this review, we discuss the principles and recent advances of In vivo molecular imaging for application of stem cell research.

Background: Tenofovir disoproxil fumarate (TDF, Viread® ) had been used as a standard treatment option of chronic hepatitis B (CHB). This clinical trial was conducted to evaluate the efficacy and safety of DA-2802 (tenofovir disoproxil orotate) compared to TDF. Methods: The present study was a double blind randomized controlled trial. Patients with CHB were recruited from 25 hospitals in Korea and given DA-2802 at a dose of 319 mg once daily or Viread® at a dose of 300 mg once daily for 48 weeks from March 2017 to January 2019. Change in hepatitis B virus (HBV) DNA level at week 48 after dosing compared to baseline was the primary efficacy endpoint. Secondary efficacy endpoints were proportions of subjects with undetectable HBV DNA, those with normal alanine aminotransferase (ALT) levels, and those with loss of hepatitis B envelop antigen (HBeAg), those with loss of hepatitis B surface antigen (HBsAg). Adverse events (AEs) were also investigated. Results: A total of 122 patients (DA-2802 group: n = 61, Viread® group: n = 61) were used as full analysis set for efficacy analysis. Mean age, proportion of males, laboratory results and virologic characteristics were not different between the two groups. The change in HBV DNA level at week 48 from baseline was −5.13 ± 1.40 in the DA-2802 group and −4.97 ± 1.40 log 10 copies/mL in the Viread® group. The analysis of primary endpoint using the nonparametric analysis of covariance showed statistically significant results (P < 0.001), which confirmed non-inferiority of DA-2802 to Viread® by a prespecified noninferiority margin of 1. The proportion of undetectable HBV DNA was 78.7% in the DA-2802 group and 75.4% in the Viread® group (P = 0.698). The proportion of subjects who had normal ALT levels was 75.4% in the DA-2802 group and 73.3% in the Viread® group (P = 0.795). The proportion of those with HBeAg loss was 8.1% in the DA-2802 group and 10.8% in the Viread® group (P = 1.000). No subject showed HBsAg loss. The frequency of AEs during treatment was similar between the two groups. Most AEs were mild to moderate in severity. Conclusion DA-2802 is considered an effective and safe treatment for patients with CHB.

Fecal microbiota transplantation (FMT) is a highly efficacious and safe modality for the treatment of recurrent or refractory Clostridioides difficile infection (CDI), with overall success rates of 90%. Thus, FMT has been widely used for 10 years. The incidence and clinical characteristics of CDI, the main indication for FMT, differ between countries. To date, several guidelines have been published. However, most of them were published in Western countries and therefore cannot represent the Korean national healthcare systems. One of the barriers to performing FMT is a lack of national guidelines. Accordingly, multidisciplinary experts in this field have developed practical guidelines for FMT. The purpose of these guidelines is to aid physicians performing FMT, which can be adapted to treat CDI and other conditions.

Objective: Fiberoptic endoscopic evaluation of swallowing (FEES) is a standard diagnostic tool for swallowing disorders. However, it has not been used frequently in Korea because of the long test time, low cost, and the absence of a standard evaluation system. The purpose of this study was to suggest a standard fill-out form for the FEES result. Methods: From February 2019 to June 2020, a total of 98 FEES tests were performed by an otolaryngologist (JYJ) at the Wonkwang University Hospital. After the exclusion of 68 cases, 30 cases were analyzed twice by 4 raters with over 5 years of experience as otolaryngologists working in various hospitals. The results were measured for the rater’s test-retest reliability and inter-rater consistency. Results: Cohen’s kappa values for measuring the intra-rater consistency of the four raters were 0.984, 0.887, 0.848, and 0.930, respectively, meaning very good alignment of 0.8 or more, respectively. The Fleiss Kappa value for measuring inter-rater consistency was 0.276, meaning ‘fair’ for values of 0.2 or more. To examine consistency, an intraclass correlation coefficient (ICC) analysis conducted by assuming the grading score to be a constant continuous variable gave an ICC value of 0.729 (P＜0.001), showing a very reliable tendency. Conclusion In this study, all the items of the fill-out form were rated using a three-step grading scale, so the degree of agreement was high when performed twice by the same rater, but the degree of agreement among raters was relatively low. Therefore, our fill-out form for FEES will be useful in evaluating the improvement of a patient over the course of clinical treatment.