In patients with differentiated thyroid cancer (DTC), initial recurrence risk stratification based on clinical, histopathological, and perioperative data remains the key determinant for guiding management strategies during the first 1-2 years post-treatment. However, the adoption of ongoing risk stratification (ORS), which dynamically reassesses risk by integrating longitudinal clinical data and treatment response, enables more precise long-term prognostic assessment and facilitates highly individualized management. Building upon recent guidelines, the 2026 KTA guideline has been further refined by incorporating robust evidence from large-scale national cohorts and comprehensive systematic reviews. These updated recommendations outline contemporary concepts of ORS, risk-adapted TSH suppression targets, optimized surveillance modalities for recurrence detection, and disease-specific long-term follow-up strategies. Reflecting the paradigm shift toward de-escalated treatment, this revision integrates evolved perspectives on TSH suppression intensity, the clinical interpretation of thyroglobulin levels, and tailored follow-up intervals. These evidence-based recommendations aim to minimize unnecessary treatment and excessive surveillance in the large proportion of patients with excellent prognosis after initial therapy, while ensuring that each patient receives appropriately tailored and effective long-term management.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

Background: Carbapenem resistance in Pseudomonas aeruginosa is a serious global health problem. We investigated the clonal distribution and its association with the carbapenem resistance mechanisms of carbapenem-non-susceptible P. aeruginosa isolates from three Korean hospitals. Methods: A total of 155 carbapenem-non-susceptible P. aeruginosa isolates collected between 2011 and 2019 were analyzed for sequence types (STs), antimicrobial susceptibility, and carbapenem resistance mechanisms, including carbapenemase production, the presence of resistance genes, OprD mutations, and the hyperproduction of AmpC β-lactamase. Results: Sixty STs were identified in carbapenem-non-susceptible P. aeruginosa isolates.Two high-risk clones, ST235 (N = 41) and ST111 (N = 20), were predominant; however, sporadic STs were more prevalent than high-risk clones. The resistance rate to amikacin was the lowest (49.7%), whereas that to piperacillin was the highest (92.3%). Of the 155 carbapenem-non-susceptible isolates, 43 (27.7%) produced carbapenemases. Three metalloβ-lactamase (MBL) genes, blaIMP-6 (N = 38), blaVIM-2 (N = 3), and blaNDM-1 (N = 2), were detected. blaIMP-6 was detected in clonal complex 235 isolates. Two ST773 isolates carried blaNDM-1 and rmtB. Frameshift mutations in oprD were identified in all isolates tested, regardless of the presence of MBL genes. Hyperproduction of AmpC was detected in MBL gene–negative isolates. Conclusions Frameshift mutations in oprD combined with MBL production or hyperproduction of AmpC are responsible for carbapenem resistance in P. aeruginosa. Further attention is required to curb the emergence and spread of new carbapenem-resistant P. aeruginosa clones.

The aim of this study was to develop evidence-based recommendations for determining the surgical extent in patients with locally invasive differentiated thyroid cancer (DTC). Locally invasive DTC with gross extrathyroidal extension invading surrounding anatomical structures may lead to several functional deficits and poor oncological outcomes. At present, the optimal extent of surgery in locally invasive DTC remains a matter of debate, and there are no adequate guidelines. On October 8, 2021, four experts searched the PubMed, Embase, and Cochrane Library databases; the identified papers were reviewed by 39 experts in thyroid and head and neck surgery. The Grading of Recommendations Assessment, Development and Evaluation (GRADE) approach was used to assess the quality of evidence, and to develop and report recommendations. The strength of a recommendation reflects the confidence of a guideline panel that the desirable effects of an intervention outweigh any undesirable effects, across all patients for whom the recommendation is applicable. After completing the draft guidelines, Delphi questionnaires were completed by members of the Korean Society of Head and Neck Surgery. Twenty-seven evidence-based recommendations were made for several factors, including the preoperative workup; surgical extent of thyroidectomy; surgery for cancer invading the strap muscles, recurrent laryngeal nerve, laryngeal framework, trachea, or esophagus; and surgery for patients with central and lateral cervical lymph node involvement. Evidence-based guidelines were devised to help clinicians make safer and more efficient clinical decisions for the optimal surgical treatment of patients with locally invasive DTC.

Background: It was reported that South Korea showed the greatest decline in the fertility rate among the entire OECD countries over the last 30 years with the total fertility rate (TFR) of 0.84 persons in 2020. Despite the efforts of the Korean government, the TFR has decreased constantly. This study intended to analyze the perception of Koreans toward pregnancy and childbirth regarding the low fertility rate in South Korea for understanding the causes of constantly decreased low fertility. Methods: This study carried out an online survey based on 1,002 men and women aged 19 to 59 years old for six days from October 21 to October 26 in 2021 in cooperation with Gallup Korea. This study analyzed the perception of people toward low fertility, the severity of low fertility, and level of interest in low fertility to inspect awareness of the severity of low fertility in South Korea through a survey. Results: It was found that 62%, 52%, and 72% of entire participants, women, and men agreed on a question “It is better to get married”. As for women’s age, a positive response for this question was derived from 34.2% (20s), 43.1% (30s), 53.4% (40s), and 71.4% (50s), respectively (P < 0.001). In a question “the necessity of children”, a positive response for this question was derived from 34.7% (20s), 58.3% (30s), 75.9% (40s), and 83.5% (50s) of female respondents, respectively (P < 0.001). Positive responses were shown 39.2%, 60.0%, 79.7%, and 81.5% of female participants in their 20s, 30s, 40s, and 50s agreed on the question “My children make me happy in my life”, respectively (P < 0.001). Conclusion This study found that a decrease in the TFR was affected mainly by the negative perception of women in their 20s and 30s toward marriage, childbirth, and the necessity of children. Therefore, further research should be conducted to develop policies that focus on these significant variables to overcome the worsening low fertility problem.

Purpose: The clinical implications of tumor-infiltrating T cell subsets and their spatial distribution in biliary tract cancer (BTC) patients treated with gemcitabine plus cisplatin were investigated. Materials and Methods: A total of 52 BTC patients treated with palliative gemcitabine plus cisplatin were included. Multiplexed immunohistochemistry was performed on tumor tissues, and immune infiltrates were separately analyzed for the stroma, tumor margin, and tumor core. Results: The density of CD8+ T cells, FoxP3- CD4+ helper T cells, and FoxP3+ CD4+ regulatory T cells was significantly higher in the tumor margin than in the stroma and tumor core. The density of LAG3- or TIM3-expressing CD8+ T cell and FoxP3- CD4+ helper T cell infiltrates was also higher in the tumor margin. In extrahepatic cholangiocarcinoma, there was a higher density of T cell subsets in the tumor core and regulatory T cells in all regions. A high density of FoxP3- CD4+ helper T cells in the tumor margin showed a trend toward better progression-free survival (PFS) (p=0.092) and significantly better overall survival (OS) (p=0.012). In multivariate analyses, a high density of FoxP3- CD4+ helper T cells in the tumor margin was independently associated with favorable PFS and OS. Conclusion The tumor margin is the major site for the active infiltration of T cell subsets with higher levels of LAG3 and TIM3 expression in BTC. The density of tumor margin-infiltrating FoxP3- CD4+ helper T cells may be associated with clinical outcomes in BTC patients treated with gemcitabine plus cisplatin.

Purpose: This study aimed to determine whether the diagnosis, treatment approach, and prognosis of multiple myeloma (MM) vary according to the presence and type of disability. Materials and Methods: Demographic, socioeconomic, and medical data were obtained from the National Disability Database, the Korean Central Cancer Registry, and the Korean National Health Insurance claims database. An age- and sex-matched cohort was established using a 1:3 ratio constituted with 2,776,450 people with disabilities and 8,329,350 people without disabilities. Adult patients diagnosed with MM were subsequently selected from this cohort. Disabilities were categorized as physical, communication, intellectual or psychological, and affecting the major internal organs. Results: The cohort included 4,090 patients with MM, with a significantly lower rate per 100,000 persons among people with disabilities than among people without disabilities (29.1 vs. 39.4, p < 0.001). People with disabilities were more likely to undergo dialysis treatment at the time of diagnosis (16.3% vs. 10.0%, p < 0.001), but were less likely to undergo autologous stem cell transplantation (37.5% vs. 43.7%, p=0.072). This trend was more evident among patients with intellectual or psychological disabilities. The median overall survival among patients with disabilities was significantly shorter than that among patients without disabilities (36.8 months vs. 51.2 months, p < 0.001). Conclusion In Korea, people with disabilities generally have a lower rate of MM diagnosis, receive less intensive treatment, and have a lower survival rate than people without disabilities.

Korean Society of Thyroid-Head and Neck Surgery appointed a Task Force to provide guidance on the implementation of a surgical treatment of oral cancer. MEDLINE databases were searched for articles on subjects related to “surgical management of oral cancer” published in English. Results were restricted to systematic reviews, randomized control trials/controlled clinical trials, and observational studies. The quality of evidence was rated with use RoBANS (Risk of Bias Assessment Tool for Nonrandomized Studies) and AMSTAR (A Measurement Tool to Assess the Methodological Quality of Systematic Reviews). Evidence-based recommendations for practice were ranked according to the American College of Physicians grading system. Additional directives are provided as expert opinions and Delphi questionnaire when insufficient evidence existed. The Committee developed 68 evidence-based recommendations in 34 categories intended to assist clinicians and patients and counselors, and health policy-makers. Proper surgical treatment selection for oral cancer, which is directed by patient- and subsite-specific factors, remains the greatest predictor of successful treatment outcomes. These guidelines are intended for use in conjunction with the individual patient's treatment goals.
Advisory Committees ; Bias (Epidemiology) ; Carcinoma, Squamous Cell ; Counseling ; Expert Testimony ; Humans ; Mouth Neoplasms ; Neck ; Republic of Korea