2.Epidemiology of Gastric Cancer in Korea (1999–2022): Incidence, Survival, and 5-Year Conditional Relative Survival
Ki Bum PARK ; Mee Joo KANG ; Johyun HA ; Eun Hye PARK ; E Hwa YUN ; Hye-Jin KIM ; Kyu-Won JUNG ; Han Hong LEE
Journal of Gastric Cancer 2026;26(1):4-15
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.
3.Protein supplementation in South Korea: balancing physiological benefits and metabolic risks for evidence-based guidelines
Kyung Won LEE ; Sangwon CHUNG ; Eunjung KIM ; Yoon Jung PARK ; Kyungho HA
Journal of Nutrition and Health 2026;59(2):159-175
Dietary protein is a crucial macronutrient for systemic homeostasis, and the global interest in protein supplements has surged because of their roles in muscle synthesis, immune function, and sarcopenia prevention. In South Korea, the proportion of energy derived from protein has increased steadily over the past decade, reflecting a significant shift in dietary patterns toward greater reliance on protein. Concurrently, a wide range of protein- and amino acidbased processed foods and dietary supplements has been developed and actively consumed.Nevertheless, comprehensive data on the prevalence of protein supplement users, their characteristics across different life stages, and the contribution of supplements to total daily protein requirements are lacking. Unlike other macronutrients, the human body lacks a dedicated reservoir for protein storage, necessitating a continuous dietary supply to support protein turnover, particularly for older adults facing anabolic resistance and individuals with high physical demands. Although clinical evidence highlights that protein supplementation, particularly when combined with resistance exercise, effectively improves muscle mass and physical performance, the magnitude of these benefits remains inconsistent across different life stages and protein sources. Conversely, emerging concerns about the potential metabolic risks from chronic overconsumption suggest that the validity and safety of protein supplementation are unclear, highlighting the need for a precision nutrition approach. Thus, this review evaluates the status of protein supplement intake among Koreans, synthesizes evidence on its physiological benefits and drawbacks and examines international trends and regulatory frameworks. Developed as part of the technical assessment for the 2025 revision of the Dietary Reference Intakes for Koreans, this review addresses the current lack of longterm safety data on chronic protein overconsumption. It provides a foundational framework for evidence-based dietary guidelines and serves as a critical scientific basis for establishing future tolerable upper intake levels and nutrition policies for protein supplement use in Korea.
4.Bioavailability of lutein following short-term consumption of raw vegetables and juice
Seung-Hui CHOI ; Kyoung Yun KIM ; Ha-Rin MOON ; Ha-Yun JEONG ; Min-Jung KANG ; Soomin LEE ; Eunju PARK ; Young-Shick HONG ; Jung-Mi YUN
Nutrition Research and Practice 2026;20(2):253-271
BACKGROUND/OBJECTIVES:
Lutein, a dietary carotenoid, plays a crucial role in protecting eye health as an anti-inflammatory agent and antioxidant. Green leafy vegetables constitute a major source of lutein; however, comparative studies on different consumption methods are limited. Therefore, this study aimed to evaluate the bioavailability of lutein from lutein-rich foods, namely, raw vegetables and raw vegetable juice.
SUBJECTS/METHODS:
In this study, 18 adults were recruited. They were randomly divided into three groups: commercial lutein supplement (LUT, 20 mg), raw vegetable (RV), and raw vegetable juice (RVJ) groups. Blood was collected at 0-, 4-, 6-, 8-, 12-, 24-, and 30-h intervals after the consumption of each test meal. Participants’ serum lutein levels were analyzed using high-performance liquid chromatography (HPLC). Considering lutein’s wellestablished anti-inflammatory properties, changes in inflammatory status were assessed by measuring serum high-sensitivity C-reactive protein (hs-CRP) levels. Furthermore, urinary metabolomic profiling was conducted using 1 H nuclear magnetic resonance spectroscopy to evaluate metabolic alterations.
RESULTS:
After consuming each lutein-rich food, participants’ blood lutein levels were analyzed, and the serum concentration peaked at 12 h (0.37 ± 0.13 μg/mL), 24 h (0.61 ± 0.18 μg/mL), and 30 h (0.42 ± 0.16 μg/mL) after RV, LUT, and RVJ consumption, respectively.Additionally, hs-CRP levels decreased following lutein-rich food consumption. Twelve hours after consumption, hs-CRP levels decreased to 0.81 and 0.83 mg/L in the RV and RVJ groups, respectively. Twenty-four hours after consumption, they further decreased to 0.68 and 0.74 mg/L in the LUT and RVJ groups, respectively. Thirty hours after consumption, a reduction to 0.61 mg/L was observed in the RVJ group. Furthermore, after consuming each luteinrich food, N-acetyl glycoprotein levels decreased at 24 h, reflecting metabolic alterations potentially associated with lutein metabolism.
CONCLUSION
These findings suggest that the short-term consumption of lutein-rich foods, regardless of their type or source, potentially yields health benefits.
5.Anti-obesity effects of Withania somnifera and Chrysanthemum zawadskii Herbich var. latilobum(Maxim.) Kitamura by regulating lipid metabolism and insulin signaling in 3T3-L1 adipocytes
Seong-Hoo PARK ; Yejin HA ; Eunhee YOO ; Jaeeun JUNG ; Mi-Ryeong PARK ; Soyoung KIM ; Jong-Lae KIM ; Jong Wook LEE ; Minhee LEE ; Ok-Kyung KIM
Nutrition Research and Practice 2026;20(1):3-15
BACKGROUND/OBJECTIVES:
Obesity is a complex metabolic disorder characterized by excessive adipose tissue accumulation, dysregulated lipid metabolism, and insulin resistance, leading to an increased risk of metabolic disease. While Withania somnifera (AS) and Chrysanthemum zawadskii Herbich var. latilobum (Maxim.) Kitamura (C) have traditionally been used for their metabolic regulatory properties, their combined effects on adipogenesis, lipogenesis, lipolysis, and insulin signaling remain unexplored. Therefore, this study aimed to evaluate the anti-obesity effects of AS, C, and their optimal combination (ASC) in 3T3-L1 adipocytes by investigating their impact on lipid metabolism and glucose homeostasis.MATERIALS/METHODS: Following adipogenic differentiation, 3T3-L1 adipocytes were treated with AS, C, and ASC at different concentrations.
RESULTS:
AS, C, and ASC significantly inhibited adipogenesis by downregulating cyclic adenosine monophosphate (cAMP) response element-binding protein, peroxisome proliferator-activated receptor gamma, CCAAT/enhancer-binding proteins alpha and beta phosphorylation, thereby reducing lipid accumulation in adipocytes. They also suppressed lipogenesis by downregulating the expression of dephosphorylated acetyl-CoA carboxylase, fatty acid synthase, and lipoprotein lipase. In contrast, they markedly enhanced lipolysis, as evidenced by increased hormone-sensitive lipase and protein kinase A expression, along with elevated glycerol release and cAMP levels. Furthermore, AS, C, and ASC activated energy metabolism pathways, as indicated by the upregulation of AMP-activated protein kinase, uncoupling protein 1, and carnitine palmitoyltransferase 1A, suggesting a transition toward enhanced mitochondrial fatty acid oxidation. Notably, AS, C, and ASC significantly improved insulin signaling by restoring insulin receptor substrate 1, phosphoinositide 3-kinase, and Akt phosphorylation, while upregulating glucose transporter type 4 expression, indicating enhanced glucose uptake. Among all treatments, ASC showed relatively greater efficacy compared to AS or C alone, suggesting a potential additive effect.
CONCLUSION
These findings demonstrate that ASC effectively modulates multiple metabolic pathways in adipocytes, including adipogenesis, lipogenesis, lipolysis, energy metabolism, and insulin signaling, to exert its anti-obesity effects.
6.Eligibility and causes of disqualification among living liver donor candidates: A single-center analysis of 991 candidates
Eun-Ju NAM ; Jong-Hyun KIM ; Hae-In SHIN ; Young-In YOON ; Deok-Bog MOON ; Ki-Hun KIM ; Tae-Yong HA ; Gi-Won SONG ; Dong-Hwan JUNG ; Gil-Chun PARK ; Shin HWANG ; Sung-Gyu LEE
Annals of Liver Transplantation 2026;6(1):17-24
Background:
A systematic evaluation of potential living liver donors is essential to ensure donor safety and optimize recipient outcomes in living donor liver transplantation (LDLT). This study aimed to assess donor acceptance rates and reasons for disqualification among individuals evaluated for LDLT at a high-volume transplant center over a one-year period.
Methods:
We retrospectively reviewed 1,087 potential living liver donors who presented for LDLT evaluation in 2023. Of these, 991 candidates advanced beyond the initial screening (Stage 1) and underwent comprehensive clinical, imaging, and pathological assessments (Stages 2 and 3). Candidates who discontinued after Stage 1 were excluded due to the absence of documented reasons for non-progression.
Results:
Among the 991 candidates who proceeded beyond initial screening, 473 (47.7%) completed the full donor evaluation, of whom 466 were judged to be suitable donors. Among suitable donors, 384 (82.4%) proceeded to donor hepatectomy, whereas 82 did not, primarily due to recipient-related factors such as clinical deterioration or withdrawal of consent. Donor ineligibility was determined in 422 candidates (42.6%), most commonly due to inadequate remnant liver volume (52.8%), hepatic steatosis (20.6%), and insufficient graft size (10.2%). Among candidates undergoing Stage 2 evaluation, 162 (16.3%) failed to meet steatosis criteria; 126 were excluded solely for steatosis and advised weight reduction, and 39 subsequently became eligible and successfully donated.
Conclusion
In this high-volume LDLT center, donor disqualification was primarily driven by remnant liver volume and hepatic steatosis. Targeted interventions such as weight reduction enabled successful donation in a subset of initially ineligible candidates, underscoring the importance of individualized donor evaluation and pre-donation optimization.
7.AFP-PIVKA-II score as a simplified quantifiable surrogate biomarker for hepatocellular carcinoma recurrence following living donor liver transplantation
Dae Hyeon WON ; Shin HWANG ; Chul-Soo AHN ; Deok-Bog MOON ; Tae-Yong HA ; Gi-Won SONG ; Dong-Hwan JUNG ; Gil-Chun PARK ; Woo-Hyoung KANG ; Young-In YOON ; Sung-Gyu LEE
Annals of Liver Transplantation 2026;6(1):25-32
Background:
We developed a simplified variant of the ADV score, the AFP-PIVKAII (AP) score for post-transplant hepatocellular carcinoma (HCC) prognosis, which considers only AFP and PIVKA-II levels excluding morphometric tumor size information from the ADV score. This study investigated the prognostic performance of the AP score in predicting HCC recurrence and overall survival (OS) after living donor liver transplantation (LDLT).
Methods:
We analyzed 843 patients with HCC who underwent LDLT between 2006 and 2015, assessing HCC recurrence and OS in relation to AP score.
Results:
The median pretransplant AFP and PIVKA-II levels were 12.8 ng/mL and 27 mAU/mL, respectively. The median and mean AP scores were 2.6 log (range: 0.6–9.2 log) and 2.9±1.1 log, respectively. The 5-year time-dependent area under the receiver operating characteristic curve for the AP score in predicting post-transplant HCC recurrence was 0.672 (p<0.001). HCC recurrence and OS curves along AP score intervals of 1.0 log showed statistical differences in accordance with the AP scores (both p<0.001). Using a Youden index J-derived AP score cutoff of 4.0 log, two-tiered groups (ADV <4.0 log vs. ADV ≥4.0 log) showed statistically significant differences in HCC recurrence and OS (both p<0.001). Harrell’s c-indices for AP score with cutoff of 4.0 log and ADV scores with cutoff of 5.0 log regarding HCC recurrence and OS were similar.
Conclusion
The AP score functions as an integrated surrogate marker for predicting post-transplant outcomes in patients with HCC undergoing LDLT. It may serve as a simplified alternative to the ADV score, particularly in patients with small HCCs.
8.Real-World Efficacy of Intravesical Gemcitabine for BCG-Unresponsive Non–muscle-Invasive Bladder Cancer
Hye Won LEE ; Eui Hyun JUNG ; Kyung Hwan KIM ; Hong Koo HA ; Jong Jin OH ; Seok Ho KANG ; Seung-hwan JEONG ; Hyeong Dong YUK ; Ji Eun HEO ; Won Sik HAM ; Eu Chang HWANG ; Seung Il JUNG ; Wan SONG ; Bumjin LIM ; Bumsik HONG ; Byung Chang JEONG ; Ho Kyung SEO
Cancer Research and Treatment 2026;58(2):591-602
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.
9.Discrepancy between Genetically Predicted and Observed Alcohol Intake and Its Impact on Gastric Cancer Susceptibility
Ga-Eun YIE ; Cheol Min SHIN ; Kyungtaek PARK ; Jinyeon JO ; Ah Ra DO ; Sungkyoung CHOI ; Jung Hun OHN ; Sejoon LEE ; Jeongseon KIM ; Sun Ha JEE ; Seung Joo KANG ; Nayoung KIM ; Sungho WON
Cancer Research and Treatment 2026;58(2):563-572
Purpose:
We aimed to investigate how genetic predisposition to drinking and gastric cancer (GC) modifies the association between alcohol consumption and GC risk in the Korean population.
Materials and Methods:
Polygenic risk scores for GC (PRS-GC) and alcohol consumption (PRS-Alcohol) were formulated using genome-wide association results from BioBank Japan. Validation was performed using Korean cohorts (SNUBH-GENIE cohort), incorporating 8,846 controls and 531 patients with GC. Subsequently, these PRSs were applied to an independent Korean cohort of 67,771 participants, including 313 patients with GC during the follow-up for 14 years (KoGES cohort).
Results:
In KoGES cohort, the influence of alcohol consumption on GC risk was significantly altered by the PRS-GC and exhibited a synergistic interaction effect. PRS-Alcohol itself shows a negative correlation with GC risk. However, when actual alcohol consumption significantly exceeded genetically predicted levels, the risk of alcohol-related GC was notably increased (adjusted hazard ratio, 1.32; 95% confidence interval, 1.01 to 1.72). Heavy drinkers in the high–PRS-GC/low–PRS-Alcohol group had a 2.16 times higher risk of GC than non-to-light drinkers, which was prominent in males.
Conclusion
Korean drinkers with higher PRS-GC who consume alcohol more than genetically predicted levels are susceptible to GC. PRS-GC and PRS-Alcohol may be beneficial for assessing the impact of alcohol consumption on GC risk in Koreans.
10.The Profile of Gut Microbiota in Carcinogenesis Driven by Mutant EGFR in Non–Small Cell Lung Cancer
Da-Som KIM ; Eun Hye KIM ; Ji Yong KIM ; Dong Ha KIM ; Yun Jung CHOI ; Jaeyi JEONG ; Young Hoon SUNG ; Dong-Cheol WOO ; Chong Jai KIM ; Jae Cheol LEE ; Miyong YUN ; Jin-Yong JEONG ; Jin Kyung RHO
Cancer Research and Treatment 2026;58(1):115-127
Purpose:
Accumulating evidence has clarified that gut dysbiosis is involved in lung cancer development and progression. Although the relationship between tumors and gut microbiota has been extensively studied using clinical samples, no studies have examined the association between mutant epidermal growth factor receptor (EGFR)–induced lung carcinogenesis and dysbiosis in gut microbiota. Therefore, we investigated the gut microbiota profiles in stool samples from human lung-specific conditional EGFR-mutant transgenic mice during lung tumor carcinogenesis.
Materials and Methods:
Stool samples were collected before tamoxifen treatment (V1) and at each time point following mutant EGFR expression in lung tissue (V2) and lung tumor appearance (V3). Fecal 16S rRNA taxonomy was analyzed to assess microbial diversity, composition, and dynamic changes at each time point.
Results:
We found that microbiota richness and diversity were significantly elevated when tumors developed and grew in the lung. Phylogenetic analysis of the microbial community revealed that Lachnospiraceae, Ruminococcaceae, Porphyromonadaceae, Rhodospirillaceae, Odoribacteraceae, and Desulfovibrionaceae showed a significant increase at the V3 stage compared to the V1 stage at the family level. In contrast, Lactobacillaceae, Bacteroidaceae, Muribaculaceae, Coriobacteriaceae, and Rikenellaceae significantly decreased at the V3 stage compared to the V1 stage. Furthermore, Lactobacillus species, also known as short chain fatty acid-producing bacteria, were relatively abundant at the V1 stage but were depleted with the occurrence of lung tumors at the V3 stage.
Conclusion
Changes in gut microbiota, such as Lactobacillus species, may be a predictive factor for the emergence and progression of tumors in an animal model of lung adenocarcinoma induced by mutant EGFR.

Result Analysis
Print
Save
E-mail