1.Korean Thyroid Association Guidelines on the Management of Differentiated Thyroid Cancers; Part II. Follow-up Surveillance after Initial Treatment 2026
Eun Kyung LEE ; Seung Heon KANG ; Bon Seok KOO ; Mijin KIM ; Min Joo KIM ; Bo Hyun KIM ; Ji Won KIM ; Dong Gyu NA ; Sohyun PARK ; Ji-In BANG ; Kyorim BACK ; Youngduk SEO ; Young-Ik SON ; Young Shin SONG ; Dong Yeob SHIN ; Jong-Hyuk AHN ; Hwa Young AHN ; So Won OH ; Ho-Ryun WON ; Won Sang YOO ; Min Kyoung LEE ; Sang-Woo LEE ; Jeongmin LEE ; Ji Ye LEE ; Dong-Jun LIM ; Ki-Wook CHUNG ; Ari CHONG ; Jin Hyang JUNG ; Sun Wook CHO ; Yoon Young CHO ; Chae Moon HONG ; Young Joo PARK ;
International Journal of Thyroidology 2026;19(1):1-40
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.
2.Calorie Restriction Modulates Gene Expression of Il19 and Il24 during Renal Aging
Sang Gyun NOH ; Hyun Woo KIM ; Seungwoo KIM ; Mi Kyung KIM ; Byung Pal YU ; Ki Wung CHUNG ; Hae Young CHUNG
Annals of Geriatric Medicine and Research 2026;30(1):28-40
Background:
Renal function declines with age as the kidneys become more vulnerable to inflammation and cellular senescence. This study examined gene expression changes linked to renal aging and assessed whether short-term calorie restriction (CR), a known anti-aging intervention, could reverse these alterations.
Methods:
Using RNA-seq data, we applied bioinformatics, systems biology, and molecular biology approaches to identify differentially expressed genes during aging and under CR. Gene Ontology and pathway analyses revealed that both aging and CR altered the expression of key senescence-associated secretory phenotype (SASP) genes, including cytokines and chemokines (Il1b, Ccl3, Ccl5, Il19, and Il24) and growth factors (Timp1 and Mmp12).
Results:
Renal aging is also associated with an increased expression of cell cycle arrest markers (p15INK4B (Cdkn2b), p16INK4A (Cdkn2a), and p21 (Cdkn1a)), which are suppressed by CR, suggesting a link to cellular senescence. Quantitative analysis of renal tissue samples confirmed the age-associated upregulation of these genes at the transcriptional level, and CR effectively attenuated these changes. Among these genes, we focused on the members of the interleukin 20 (IL-20) family, particularly Il19 and Il24. Furthermore, experimental induction of cellular senescence using H2O2 resulted in elevated Il19 and Il24 expression alongside other senescence markers. These findings suggest that aging and short-term CR regulate the IL-20 family expression, potentially influencing cellular senescence.
Conclusion
Our study suggests that Il19 and Il24 are associated with age-related renal decline and may represent hypothesis-generating candidates, highlighting potential molecular targets for future mechanistic and therapeutic investigations.
3.Progesterone receptor expression and its prognostic role in hormone receptor-positive/human epidermal growth factor receptor 2-positive breast cancer: a retrospective cohort study
Ji Hye KIM ; Yeryung KIM ; Jai Hyun CHUNG ; Yong Yeup KIM ; Woo Young KIM ; Jae Bok LEE ; Sang Uk WOO
Annals of Surgical Treatment and Research 2026;110(2):112-118
Purpose:
While progesterone receptor (PR) negativity in luminal-type breast cancer is generally associated with worse oncologic outcomes, its prognostic role in estrogen receptor (ER)-positive, human epidermal growth factor receptor 2 (HER2)-positive breast cancer remains underexplored. This study aimed to evaluate the prognostic significance of PR expression in ER-positive, HER2-positive breast cancer.
Methods:
A retrospective analysis was conducted on patients diagnosed with ER-positive, HER2-positive breast cancer who underwent primary surgery at Korea University Guro Hospital between January 2009 and December 2019. Patients were grouped by PR expression as negative/low (Allred score, 0–6) or strongly positive (Allred score,7 or 8). Prognostic outcomes, including disease-free survival (DFS), distant recurrence-free survival (DRFS), and breast cancer-specific survival (BCSS) were analyzed.
Results:
A total of 223 patients were included. Patients in the negative/low PR group were older compared to the strongly positive PR group. The negative/low PR group showed significantly worse DFS (P = 0.005) and DRFS (P = 0.014) but showed no significant difference in BCSS (P = 0.153). On multivariate analysis, negative or low PR expressions were linked to inferior DFS (hazard ratio [HR], 3.10; 95% confidence interval [CI], 1.34–7.16; P = 0.008) and DRFS (HR, 9.55; 95% CI, 1.22– 74.77; P = 0.032).
Conclusion
In ER-positive, HER2-positive breast cancer, negative or weak PR expression was associated with inferior DFS and DRFS compared to strong PR expression. These findings highlight the potential prognostic value of PR status in this group, underscoring its relevance in guiding treatment and follow-up strategies for more individualized patient care.
4.Long-term Immunogenicity of the 13-valent Pneumococcal Conjugate Vaccine during Adjuvant Chemotherapy in Patients with Gastric and Colorectal Cancer: A 5-Year Follow-up of a Randomized Controlled Trial
Hyeon-Jong KIM ; Hyunjin BANG ; Hyun-Jung SHIM ; Jun Eul HWANG ; Sang-Hee CHO ; Ik-Joo CHUNG ; Seung Ji KANG ; Jong Gwang KIM ; Seung-Hoon BEOM ; A-Yeung JANG ; Joon Young SONG ; Woo Kyun BAE
Cancer Research and Treatment 2026;58(1):61-70
Purpose:
Current guidelines recommend vaccination at least 2 weeks before chemotherapy initiation to optimize the immune response despite limited evidence. Our previous study indicated no differences in short-term immune response for the 13-valent pneumococcal conjugate vaccine (PCV13) according to the vaccination timing. This study aims to investigate the long-term efficacy of PCV13 and clinical factors associated with the respective antibody response.
Materials and Methods:
Patients with gastric or colorectal cancer who received adjuvant chemotherapy were enrolled and divided into two groups: vaccinated 2 weeks before chemotherapy (arm A) and vaccinated concurrently with chemotherapy (arm B). Serum samples were collected before vaccination and in one month, 3 years, and 5 years. Immune responses were measured using enzyme-linked immunosorbent assay and multiplex opsonophagocytosis assay.
Results:
Including 63 patients, both groups showed an initial increase in the geometric mean titers of opsonophagocytic activity and the geometric mean concentrations of serotype-specific IgG levels after one month, followed by a decline at 3 and 5 years, particularly for serotypes 1, 14, 18C, and 19A. Despite the decline, global protection was maintained for 5 years, although global response decreased. The two arms did not show significant differences in immunogenicity nor in factors such as vaccination timing, age, cancer type, or chemotherapy regimen.
Conclusion
Vaccination timing is not a significant factor for the immunogenicity of PCV13 in cancer patients undergoing adjuvant chemotherapy. Global protection against pneumococcal infection was sustained for > 5 years, and global response remained in over half of patients.
5.Psychological Characteristics Associated With Cyberbullying:Focusing on the Victim-Perpetrators and Gender Differences
Geon-Taek BAE ; Sang-Ick LEE ; Chul-Jin SHIN ; Jung-Woo SON ; Siekyeong KIM ; Gawon JU ; Jeonghwan LEE ; Joon Hyung JUNG ; Seungwon CHUNG
Journal of the Korean Academy of Child and Adolescent Psychiatry 2026;37(2):95-104
Objectives:
Cyberbullying is a modern form of violence involving intentional harassment through electronic devices. We aimed to investigate how psychological characteristics differ based on cyberbullying involvement, identify the psychological factors associated with cyberbullying, and examine whether these factors vary by gender.
Methods:
A survey was conducted with 449 middle school students in Cheongju, Korea. Participants were categorized into four groups based on their involvement: Neither (N), Victim (V), Perpetrator (P), and Victim-Perpetrator (VP). Psychological characteristics were assessed using the Beck Depression Inventory (BDI), Self-Esteem Scale, and Strengths and Difficulties Questionnaire (SDQ). We compared these characteristics across the four groups and examined their influence on cyberbullying involvement by gender.
Results:
Overall, 31.8% of participants were involved in cyberbullying, with the VP group being the largest (17.1%) among them. The VP group exhibited more severe psychopathology than the N group across most internalizing and externalizing problems. SDQ-Conduct Problems subscale scores were significantly associated with victimization and perpetration. For female participants, high SDQEmotional Symptoms subscale scores were associated with greater victimization, and high BDI scores increased the risk of belonging to the VP group. No variables significantly increased the risk of belonging to the VP group among male participants.
Conclusion
Adolescents who are both victims and perpetrators of cyberbullying face the most significant psychological difficulties.Factors associated with cyberbullying involvement vary by gender, highlighting the need for tailored gender-specific prevention and intervention strategies.
6.Associated factors of osteoporosis and the impact of osteoporosis on all-cause mortality in incident hemodialysis older patients
Seunghye LEE ; Yoomee KANG ; Yu Ah HONG ; Sung Joon SHIN ; Soon Hyo KWON ; Sungjin CHUNG ; Young Youl HYUN ; Sang Heon SONG ; Jae Won YANG ; Won Min HWANG ; Jang-Hee CHO ; Kyung Don YOO ; In O SUN ; Gang-Jee KO ; Byung Chul YU ; Hyunsuk KIM ; Woo Yeong PARK ; Tae Won LEE ; Dong Jun PARK ; Eunjin BAE ;
Kidney Research and Clinical Practice 2026;45(1):110-119
Background:
With the aging population and advancements in medical care worldwide, the number of older patients with end-stage kidney disease continues to rise. This study aimed to identify factors associated with osteoporosis and osteopenia in older patients undergoing incident hemodialysis and assess their impact on mortality.
Methods:
We analyzed a large multicenter retrospective cohort of patients aged ≥70 years undergoing incident hemodialysis to identify factors associated with osteoporosis using logistic regression analysis and to assess the association of death with osteoporosis and osteopenia using Cox multivariable analysis.
Results:
Among 710 patients, 39.0% and 19.6% had osteoporosis and osteopenia, respectively. Osteoporosis was significantly associated with female sex, a history of fractures, and the absence of phosphate binder use. During a median follow-up of 36.8 months, 348 participants (58.8%) died. Mortality rates were the highest in the osteoporosis group (79.8%), followed by the osteopenia (77.2%) and normal bone mineral density (BMD) groups (35.2%). Cox regression analysis revealed that even after adjusting for covariates, the osteoporosis group was significantly associated with a higher mortality risk than the normal BMD group. Osteoporosis at the start of hemodialysis was significantly associated with higher mortality.
Conclusion
We should consider the importance of bone health in patients undergoing incident hemodialysis and pay attention to the use of phosphate binders and fracture prevention.
7.Impact of obesity on renal function in elderly Korean adults: a national population-based cohort study
Jihyun YANG ; Hui Seung LEE ; Chi-Yeon LIM ; Hyunsuk KIM ; Sungjin CHUNG ; Soon Hyo KWON ; Jang-Hee CHO ; Kyung Don YOO ; Woo Yeong PARK ; In O SUN ; Byung Chul YU ; Gang-Jee KO ; Jae Won YANG ; Won Min HWANG ; Sang Heon SONG ; Sung Joon SHIN ; Yu Ah HONG ; Eunjin BAE ; Young Youl HYUN
Kidney Research and Clinical Practice 2026;45(1):65-76
Background:
Obesity is a well-known risk factor for chronic kidney disease and its progression. However, the impact of obesity on the renal function of the elderly population is uncertain. We investigated the association between obesity and renal outcomes in the elderly.
Methods:
We analyzed 130,504 participants from the Korean National Health Insurance Service-Senior cohort. Obesity was classified according to body mass index (BMI), sex-specific waist circumference (WC), and the presence of metabolic syndrome. The primary outcome was renal function decline, defined as a decline in the estimated glomerular filtration rate (eGFR) of at least 50% from baseline or new-onset end-stage renal disease.
Results:
During a follow-up period of 559,531.1 person-years (median, 4.3 years), 2,486 participants (19.0%; incidence rate of 4.44 per 1,000 person-years) showed renal function decline. A multivariate Cox proportional hazards model revealed that BMI/WC was not associated with renal function decline. However, the group with metabolic syndrome had a significantly increased risk of renal function decline compared to the group without metabolic syndrome (adjusted hazard ratio [HR], 1.24; 95% confidence interval [CI], 1.13–1.36). Compared with the non-metabolic syndrome group, the adjusted HRs (95% CI) for participants with one through five components were 0.96 (0.84–1.11), 1.10 (0.96–1.27), 1.24 (1.06–1.45), 1.37 (1.12–1.66), and 1.99 (1.42–2.79), respectively (p for trend < 0.001).
Conclusion
In elderly Korean adults, metabolic syndrome and the number of its components were associated with a higher risk of renal function decline, but BMI or WC was not significant.
8.Breast Cancer in Older Patients Aged 70 Years and Above: Treatment Adherence and Oncologic Outcomes
Ji Hye KIM ; Yong Yeup KIM ; Jai Hyun CHUNG ; Woo Young KIM ; Jae Bok LEE ; Sang Uk WOO
Journal of Breast Cancer 2025;28(2):99-107
Purpose:
The incidence of breast cancer in older females is increasing with increased life expectancy. This study analyzed tumor characteristics and oncological outcomes in patients aged ≥ 70 years compared to patients in a younger postmenopausal group, in conjunction with their adherence to treatment guidelines.
Methods:
Patients aged ≥ 50 years, newly diagnosed with breast cancer, were divided into two age categories: ≥ 70 years and 50–69 years. All patients underwent curative surgery at Korea University Guro Hospital between January 2009 and December 2019. Clinical data on tumor subtype, histopathological grade, and clinical stage, along with treatment details were collected. Disease-free survival, distant recurrence-free survival, and breast cancer-specific survival rates were determined.
Results:
Of 1,199 patients, 166 (13.8%) were ≥ 70 years at the time of surgery. The diseasefree, distant recurrence-free, and breast cancer-specific survival rates were significantly lower in patients aged ≥ 70 years (p < 0.05). In a subgroup analysis, human epidermal growth factor receptor 2-positive tumors were the only subtype with a statistically significant difference in survival outcomes, and adherence to the guidelines was strongly linked to a better prognosis.
Conclusion
Patients aged ≥ 70 years had lower disease-free, distant recurrence-free, and breast cancer-specific survival rates compared to younger postmenopausal patients aged 50–69 years. With the continuous increase in life expectancy and advances in healthcare, it is critical to optimize treatment strategies for older patients with breast cancer to improve survival outcomes and enhance their quality of life.
9.A comparative study on efficacy and safety of modified partial stapled hemorrhoidopexy versus conventional hemorrhoidectomy: a prospective randomized controlled trial
Tae Gyu KIM ; Chul Seung LEE ; Dong Geun LEE ; Choon Sik CHUNG ; Seung Han KIM ; Sang Hwa YU ; Jeong Eun LEE ; Gwan Cheol LEE ; Dong Woo KANG ; Jeong Sub KIM ; Gyu Young JEONG
Annals of Coloproctology 2025;41(2):145-153
Purpose:
The long-term outcomes and efficacy of partial stapled hemorrhoidopexy (PSH) compared with those of conventional hemorrhoidectomy (CH) are not fully understood. This study aimed to introduce a modified PSH (mPSH) and compare its clinical efficacy and safety with those of CH.
Methods:
A prospective randomized controlled trial was conducted. This study was performed at a single hospital and involved 6 colorectal surgeons. In total, 110 patients were enrolled between July 2019 and September 2020. Patients were randomly assigned to undergo either mPSH group (n=55) or CH group (n=55). The primary outcome was to compare postoperative average pain and postoperative peak pain using visual analog scale score between the 2 groups.
Results:
The required duration of analgesia was shorter in the mPSH group than in the CH group, although the difference was not statistically significant (P=0.096). However, the laxative requirement duration (P<0.010), return to work (P<0.010), satisfaction score (P<0.010), and Vaizey score (P=0.014) were significantly better in the mPSH group. The average and peak postoperative pain scores were significantly lower in the mPSH group during the 15 days after surgery (P<0.001). The overall complication rate in both groups was 9.1%, with no significant difference between the groups (P=0.867).
Conclusion
The mPSH group demonstrated better improvement in symptoms, lower pain scores, and greater patient early satisfaction after surgery than the CH group. Therefore, this surgical technique appears to be a safe and effective alternative for CH.
10.Safety and efficacy of HK-660S in patients with primary sclerosing cholangitis: A randomized double-blind phase 2a trial
Woo Hyun PAIK ; Joo Kyung PARK ; Moon Jae CHUNG ; Gunn HUH ; Ce Hwan PARK ; Sang Hyub LEE ; Heon Se JEONG ; Hee Jin KIM ; Do Hyun PARK
Clinical and Molecular Hepatology 2025;31(1):119-130
Background/Aims:
A clinical unmet need persists for medications capable of modulating the progression of primary sclerosing cholangitis (PSC). This study aimed to assess the clinical feasibility of HK-660S (beta-lapachone) in PSC.
Methods:
In this multicenter, randomized, double-blind, placebo-controlled, parallel-group phase 2 trial, participants were assigned in a 2:1 ratio to receive either 100 mg of HK-660S or a placebo twice daily for 12 weeks. The primary outcomes were the reduction in serum alkaline phosphatase (ALP) levels and the percentage of participants showing improvements in PSC severity, as determined by magnetic resonance cholangiopancreatography with the Anali score. Secondary endpoints included changes in liver stiffness and adverse events.
Results:
The analysis included 21 patients, 15 receiving HK-660S, and six receiving a placebo. Improvements in the Anali score were observed in 13.3% of the HK-660S group, with no improvements in the placebo group. HK-660S treatment resulted in a 15.2% reduction in mean ALP levels, compared to a 6.6% reduction in the placebo group. A stratified ad-hoc analysis based on baseline ALP levels showed a statistically significant response in the HK-660S group among those with ALP levels greater than twice the upper limit of normal, with a 50% responder rate (p=0.05). Additionally, 26.7% of the HK-660S group showed improvements in the enhanced liver fibrosis score, with no improvements in the placebo group. HK-660S was generally well tolerated.
Conclusions
HK-660S is well tolerated among patients with PSC and may improve bile duct strictures, decrease serum ALP levels, and reduce liver fibrosis (cris.nih.go.kr, Number KCT0006590).

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