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.

Objectives: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes. Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5460 ESD cases from 5250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

The efficacy of clarithromycin-containing triple therapy (TT) against Helicobacter pylori has declined in Korea, with recent first-line eradication rates falling below 70%. Clarithromycin resistance exceeded 30%, undermining the standard regimen for H. pylori. These trends necessitate a change in the treatment strategy. This review analyzed the shift proposed in the draft of the 2025 Korean H. pylori guidelines. We examined the rationale for abandoning TT as a first-line empirical therapy and the establishment of a new dual-pillar strategy: 1) the declining role of clarithromycin-containing TT as a first-line treatment and 2) polymerase chain reaction (PCR)-based tailored therapy as the recommended precision approach. We explored the 1) emergence of new empirical regimen options, 2) application of tailored therapy, and 3) adoption of potassium-competitive acid blockers (P-CABs). Empirical regimens have shifted toward four-drug combinations to achieve higher cure rates. Concomitant therapy (proton-pump inhibitor [PPI] or P-CAB+amoxicillin+clarithromycin+metronidazole) offers high efficacy but raises concerns about antibiotic overuse. As a compromise, bismuth-augmented triple regimens (adding bismuth to TT) are now recommended; these modified quadruple therapies (e.g., PACB: PPI+amoxicillin+clarithromycin+bismuth, or PAMB: PPI+amoxicillin+metronidazole+bismuth) significantly improve eradication rates without requiring a third antibiotic class. Regarding tailored therapy, PCR-based domestic clinical research data consistently achieves ≥90% cure rates in first-line treatment—markedly higher than empirical TT in Korea. Economic analyses supported the cost-effectiveness of this approach. The guideline algorithm for salvage therapy was clarified. Bismuth quadruple therapy has been confirmed as the standard second-line treatment. For third-line therapy, we analyzed the efficacy of levofloxacin-based regimens, rifabutin-based therapy, and bismuth add-on therapy with two previously unused antibiotics. The 2025 Korean guidelines establish quadruple therapies as the new standard through a dual strategy: pragmatic empirical treatment and PCR-guided tailored therapy, with P-CABs and bismuth-based regimens as key components.

Purpose: Endoscopic submucosal dissection (ESD) has become a standard minimally invasive treatment for selected patients with early gastric cancer (EGC). This study presents the first nationwide survey of patients with EGC treated with ESD in 2023, conducted by the Korean College of Helicobacter and Upper Gastrointestinal Research. Materials and Methods: Data were retrospectively collected from participating referral centers across Korea using a standardized case report form covering patient characteristics, tumor features, procedural details, histopathological findings, and clinical outcomes.Descriptive and comparative analyses were conducted to summarize nationwide ESD practice patterns and outcomes. Results: Data from 5,460 ESD cases from 5,250 patients across 27 institutions were analyzed. The mean age was 67.4 years, with 74.1% males. Multiple synchronous lesions were identified in 3.7%. Most lesions were located in the lower third of the stomach (64.0%), and differentiated-type adenocarcinomas accounted for 87.8%. The en bloc and complete resection rates were 99.2% and 91.4%, respectively. Curative resection was achieved in 80.5%, whereas local non-curative resection (L-NCR) and surgical non-curative resection (S-NCR) were identified in 2.8% and 16.7%, respectively. Additional surgery was performed more frequently in patients with S-NCR than in those with L-NCR (59.3% vs. 24.7%). The bleeding and perforation rates were 3.6% and 0.9%, respectively, and were mostly managed conservatively or endoscopically. The median length of hospitalization was 4.0 days. Conclusions This first nationwide survey provides a comprehensive overview of the current practice of EGC treatment using ESD in Korea, demonstrating high technical success and safety, and establishing a baseline dataset for future longitudinal research.

Purpose: This study evaluated long-term trends in gastric cancer epidemiology and survival with a focus on conditional relative survival (CRS). Materials and Methods: Using the Korea Central Cancer Registry, we analyzed 665,184 patients who were newly diagnosed with gastric cancer between 1999 and 2022.The study period was divided into four intervals: Period I (1999–2005), Period II (2006–2011), Period III (2012–2017), and Period IV (2018–2022). Temporal trends in the incidence and mortality were assessed using crude and age-standardized rates. Relative survival was estimated using the Ederer II method, and the 5-year CRS was calculated according to the survival duration after diagnosis. Results: The incidence of gastric cancer increased until 2011 and subsequently declined, with a marked decrease observed in 2020. Individuals aged ≥70 years consistently had the highest incidence rates. Mortality rates showed a sustained decline throughout the study period. The overall 5-year relative survival improved from 69.8% in Period II to 78.4% in Period IV. The 5-year CRS increased from 86.1% at 1 year after diagnosis to 96.3% at 5 years.Patients with localized stage maintained a 5-year CRS above 95% at 1 year after diagnosis, whereas those with regional and distant stages showed 5-year CRS that consistently remained below 95%. Conclusions The incidence and mortality rates of gastric cancer in Korea have declined over the past two decades, accompanied by improved survival outcomes. The CRS analysis suggests that long-term follow-up is warranted, with the optimal duration varying according to patient characteristics.

Background/Aims: Endoscopic anti-reflux therapy is a therapeutic option for gastroesophageal reflux disease (GERD), providing durable effects. However, clinical data from Korea remain limited. This study evaluates the clinical outcomes of endoscopic radiofrequency Stretta therapy in Korean patients. Methods: A retrospective analysis was conducted on 71 patients with GERD who underwent Stretta therapy at 2 tertiary hospitals in Korea between November 2015 and July 2021. Clinical outcomes, including patient satisfaction, medication cessation or reduction, and complications, were evaluated. Pre- and post-procedural esophageal manometry and 24-hour pH monitoring test results were also analyzed. Results: Patient satisfaction rates at 1, 6, and 12 months post-procedure were 54.7% (35/64), 70.0% (28/40), and 75.0% (21/28), respectively. Medication cessation or reduction was achieved in 31.2% (20/64) at 1 month, 70.0% (28/40) at 6 months, and 67.9% (19/28) at 12 months. Esophageal manometry (n = 21) showed no significant changes in mean lower esophageal sphincter pressure (18.7 mmHg [2.5-52.9] vs 17.4 mmHg [0.0-43.0], P = 0.702) or mean integrated relaxation pressure (8.2 mmHg [0.0-28.0] vs 10.1 mmHg [0.0-31.0], P = 0.840). The 24-hour pH monitoring (n = 18) demonstrated a nonsignificant decrease in acid exposure time (pH < 4) from 2.3% (0.0-8.4) to 1.6% (0.0-7.3) (P = 0.182). Similarly, the DeMeester score decreased non-significantly from 8.4 (0.8-27.7) to 6.6 (0.8-21.8) (P = 0.352). No procedure-related complications occurred. Conclusion Endoscopic radiofrequency Stretta therapy appears to be a safe treatment option for GERD and may provide favorable patient satisfaction and medication reduction.

BACKGROUND/OBJECTIVES: Dietary supplement use is common among breast cancer survivors, but studies on Asian populations remain limited. This study investigated dietary supplement use among Korean breast cancer survivors, distinguishing between vitamin/ mineral (VM) and non-vitaminon-mineral (NVNM) supplements. SUBJECTS/METHODS: This cross-sectional study included 1,136 stage I–III breast cancer survivors from 12 Korean hospitals, who survived more than 6 mon post-surgery. The participants completed a questionnaire on post-diagnostic dietary supplement use. Stepwise logistic regression was applied, calculating odds ratios (ORs) and 95% confidence intervals (CIs) to identify the demographic and clinical factors associated with VM and NVNM use. RESULTS: Seventy percent of survivors reported supplement use, with 25% using a single product. The most common VM supplements were multivitamins/minerals, vitamin D, and vitamin C, while the most common NVNM supplements included omega-3 fatty acids, probiotics, and ginseng. Survivors with higher education and greater physical activity were more likely to use VM supplements (ORs [95% CIs], 2.74 [1.76–4.25] for college graduates or above vs. middle school or below; 1.38 [1.02–1.88] for the most active group vs. the least active group). NVNM use was associated with higher education, greater physical activity levels, and a history of smoking (ORs [95% CIs], 2.29 [1.46–3.58] for college graduates or above vs. middle school or below; 1.52 [1.13–2.06] for the most active group vs. the least active group; 2.00 [1.23–3.25] for ever smokers vs. never smokers). Survivors who had undergone chemotherapy were also more likely to use NVNM supplements than those who had not (OR [95% CI], 1.37 [1.02–1.84]). CONCLUSION Seventy percent of Korean breast cancer survivors used dietary supplements in this study. VM use was associated with higher education and physical activity, while higher NVNM use was associated with higher education, greater physical activity, a history of smoking, and chemotherapy.

Purpose: This study aimed to project cancer incidence and mortality for 2026 to estimate Korea’s current cancer burden. Materials and Methods: Cancer incidence data from 1999 to 2023 were obtained from the Korea National Cancer Incidence Database, while cancer mortality data from 1993 to 2024 were acquired from the Ministry of Data and Statistics. Cancer incidence and mortality were projected by fitting a linear regression model to observed age-specific cancer rates against their respective years and then by the projected age-specific rates by the anticipated age-specific population for 2026. A joinpoint regression model was applied to identify significant changes in trends, using only the most recent trend data for predictions. Results: A total of 308,876 new cancer cases and 86,317 cancer deaths are expected in Korea in 2026. The most commonly diagnosed cancer is projected to be thyroid cancer, followed by the colorectal, lung, breast, prostate and stomach cancers. These six cancers are expected to account for 63.5% of all newly diagnosed cancers. Lung cancer is expected to be the leading cause of cancer-related deaths, followed by liver, colorectal, pancreatic, gallbladder, and stomach cancers, together comprising 65.9% of all cancer deaths. Conclusion Korea’s cancer burden continues to shift toward malignancies prevalent in older populations. The sustained increase in prostate cancer among men and the rising mortality impact of pancreatic cancer reflect structural changes in the national cancer profile amid rapid population aging.

Purpose: The current study provides national cancer statistics and their secular trends in Korea, including incidence, mortality, survival, and prevalence in 2023, with international comparisons. Materials and Methods: Cancer incidence, survival, and prevalence rates were calculated using the Korea National Cancer Incidence Database (1999-2023), with survival follow-up until December 31, 2024. Mortality data were obtained from the Ministry of Data and Statistics, while international comparisons were based on GLOBOCAN data. Results: In 2023, 288,613 newly diagnosed cancer cases (age-standardized rate [ASR], 288.6 per 100,000) and 85,271 deaths from cancer (ASR, 64.3 per 100,000) were reported. Among the incident cases, 145,452 (50.4%) were aged 65 years or older. Prostate cancer became the most common cancer among men for the first time. The proportion of localized-stage cancers increased from 45.6% in 2005 to 51.8% in 2023. Korea had the lowest cancer mortality among countries with similar incidence rates and the lowest mortality-to-incidence ratios for stomach, colorectal, and breast cancer. The 5-year relative survival rate (2019-2023) was 73.7% overall and 92.7% for localized-stage cancers. Over 2.73 million prevalent cases were identified in 2023, representing 5.3% of the Korean population. Conclusion These findings indicate that Korea’s cancer control efforts have contributed to early detection and improved survival outcomes. As Korea enters a super-aged society in 2025, cancer burden will continue to increase, requiring sustained and adaptive cancer control strategies.

Purpose: This study aimed to report the real-world outcomes of intravesical gemcitabine for bacillus Calmette–Guérin (BCG)–unresponsive, high-risk, non–muscle-invasive bladder cancer (HR-NMIBC) in Korean patients who were unable or unwilling to undergo radical cystectomy (RC). Materials and Methods: This retrospective study included 131 patients (median age, 69 years; 88.5% men) treated with intravesical gemcitabine for BCG-unresponsive HR-NMIBC at nine centers between May 2019 and April 2022. The primary endpoint was 1-year recurrence-free survival (RFS). The secondary endpoints included factors influencing RFS, progression-free survival (PFS), cystectomy- free survival, cancer-specific survival (CSS), overall survival (OS), and safety. Survival analysis was performed using the Kaplan-Meier method, and risk factors for recurrence were assessed using Cox regression models. Results: Patients were followed up for a median duration of 25 months, with carcinoma in situ (CIS) in 41.9% of the patients. The 1-year and 2-year RFS rates were 68% and 42%, while the 1-year and 2-year PFS rates were 87% and 77%, respectively. No significant factors influencing RFS were identified. Seventeen patients underwent RC during a median follow-up of 16 months, with the condition in three patients progressing to muscle-invasive disease on final pathological analysis. The 2-year CSS and OS rates were 98% and 97%, respectively. Intravesical gemcitabine was well-tolerated, with only seven patients (5.3%) unable to complete the full induction course. Conclusion Our research highlights the potential of intravesical gemcitabine as a viable bladder-sparing treatment option for BCG-unresponsive HR-NMIBC, providing real-world evidence on its safety, efficacy, and tolerability.