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.Clinical Outcomes of Lobular Carcinoma In Situ: Risk of Invasive Cancer Development
Doyoun WOEN ; Ki Jo KIM ; Su Min LEE ; Seungah LEE ; Kawon OH ; Cho Eun LEE ; Seok Jin NAM ; Seok Won KIM ; Jeong Eon LEE ; Byung Joo CHAE ; Se Kyung LEE ; Jai Min RYU ; Woong Ki PARK ; Hyunwoo LEE ; Jonghan YU
Journal of Breast Cancer 2026;29(2):163-174
Purpose:
Lobular carcinoma In Situ (LCIS) is a noninvasive lesion associated with an increased risk of invasive cancer. Since its removal from the tumor, node, metastasis classification in the 8th edition of the American Joint Committee on Cancer (AJCC) guidelines, the clinical management of LCIS has shifted from surgery to surveillance. However, studies focusing on the risk and associated factors for invasive cancer development in pure LCIS without ductal carcinoma In Situ (DCIS) or invasive cancer remain limited.
Methods:
We retrospectively analyzed 106 patients diagnosed with pure LCIS between 2008 and 2018. This study evaluated the effect of tamoxifen use and histologic type on the development of invasive cancer.
Results:
All 106 patients underwent surgery, and nine (8.5%) developed invasive cancer over a median follow-up of 67.5 months. The incidence of invasive cancer was lower in the tamoxifen group (6.3%, n = 4) than in the non-tamoxifen group (11.9%, n = 5), although this difference was not statistically significant (p = 0.266). Pleomorphic LCIS had a significantly higher incidence of invasive cancer (30.0%, n = 3) than classic LCIS (6.3%, n = 6) (p = 0.045).Multivariable Cox regression analysis showed no significant difference in the risk of invasive cancer according to tamoxifen use (hazard ratio [HR], 2.031; 95% confidence interval [CI], 0.544–7.579; p = 0.292). However, pleomorphic LCIS showed a trend toward an increased risk of invasive cancer compared to classic LCIS (HR, 3.856; 95% CI, 0.922–16.126; p = 0.064).
Conclusion
Postoperative tamoxifen did not significantly lower invasive cancer development in patients with pure LCIS. Pleomorphic LCIS may carry a higher risk than classic LCIS. These findings require tailored follow-up and treatment strategies based on the histologic subtype of LCIS.
3.Comparative survival outcomes of surgical resection versus radiotherapy after FOLFIRINOX in borderline resectable and locally advanced pancreatic cancer
Jiwon YU ; Jeong Ha LEE ; Hyunju SHIN ; Hee Chul PARK ; Joon Oh PARK ; Jung Yong HONG ; Minsuk KWON ; Ji Eun SHIN ; Kyu Taek LEE ; Kwang Hyuck LEE ; Jong Kyun LEE ; Joo Kyung PARK ; Young Hoon CHOI ; Jin Seok HEO ; In Woong HAN ; Sang Hyun SHIN ; Hongbeom KIM ; Ji Hye MIN ; Jeong Il YU
Precision and Future Medicine 2026;10(1):39-50
Purpose:
This study evaluated the clinical outcomes and prognostic factors in patients with borderline resectable pancreatic cancer (BRPC) and locally advanced pancreatic cancer (LAPC) treated with upfront FOLFIRINOX followed by local-regional therapy (LRT), surgical resection (SR), and radiotherapy (RT). We aimed to identify specific patient subgroups for which RT may serve as a reasonable alternative to SR for local tumor control.
Methods:
We retrospectively analyzed 116 patients (SR group, n= 70; RT group, n= 46) at a single center between 2015 and 2020. Survival outcomes were compared based on LRT modalities, focusing on identifying subgroups in which RT provided an efficacy comparable to that of SR.
Results:
Among 116 patients, the SR group achieved a significantly higher 5-year overall survival (OS) than the RT group (27.1% vs. 8.7%, P< 0.0001), despite similar progression-free survival (P= 0.23). Significant prognostic factors for OS included carbohydrate antigen 19-9 (CA19-9) response in BRPC (P= 0.02) and radiologic partial response in LAPC (P= 0.05). Subgroup analysis revealed that, while SR provided a survival advantage in CA19-9 responders, no significant difference in OS was observed between SR and RT in CA19-9 non-responders (P= 0.37).
Conclusion
Although surgery remains the gold standard, RT may be considered a justifiable local alternative for CA19-9 non-responders and surgically ineligible patients with LAPC, yielding comparable outcomes in these specific, biologically unfavorable subgroups.
4.Multicenter evaluation of the PASS score as a negative predictive tool and the impact of inter-observer variability in pheochromocytoma and paraganglioma risk stratification
Sungyeon JUNG ; Hye-Ri SHIN ; Su-Jin SHIN ; Hee Young NA ; Soon-Won HONG ; So Yeon PARK ; Chan Kwon JUNG ; Kyeong Cheon JUNG ; Young Lyun OH ; Jae-Kyung WON
Journal of Pathology and Translational Medicine 2026;60(2):202-213
The Pheochromocytoma of the Adrenal Gland Scaled Score (PASS) is widely used for risk stratification in pheochromocytoma and paraganglioma (PPGL), but its clinical utility is limited by inter-observer variability of its parameters and inconsistent predictive performance. Methods: We conducted a multicenter retrospective study of 1,518 patients with PPGL from five tertiary referral centers in Korea. Prognostic utility of PASS system was assessed using logistic regression, Kaplan-Meier analysis, and receiver operating characteristic (ROC) curve analysis. Inter-observer variability was inferred by comparing area under the ROC curve (AUCs) across institutions. Simplified PASS systems were developed based on multivariable analysis of key histopathological parameters. Results: The PASS system was a significant predictor of adverse events and recurrence-free survival. Although the PASS system demonstrated only modest discriminative ability (AUC, 0.673), it showed a high negative predictive value (NPV, 0.885), supporting its usefulness as a screening tool for benign behavior. However, there was significant inter-institutional variability in PASS performance (AUC; range, 0.513 to 0.727; p < .05). The 3-factor Simple PASS, which incorporates necrosis, spindling, and mitotic figures, exhibited less inter-observer variation. The 4-factor Simple PASS, which adds vascular invasion to the 3-factor model, also showed reduced inter-observer variability and improved AUC and NPV compared to the original PASS system. Conclusions: In this multicenter cohort, the PASS system demonstrated high NPV and screening potential, but significant inter-observer variability remains a challenge. Simplification of the PASS system and enhanced pathologist training may improve reproducibility and clinical utility in PPGL risk stratification.
5.Shifting the Paradigm of Medical Dispute Resolution: From Individual Punishment to System Improvement and Public Compensation
Hee Gyung KANG ; Eun Kyung EO ; Duseop KWON ; Sung-ju KIM ; HaDa RYUOK ; Serng Bai PAK ; Junghee AHN ; Minsu OCK ; Mihwa YOO ; Sang-il LEE ; Eunyoung CHO ; Eun Jin HA ; DongSeok HAN ; Juhwan OH
Korean Journal of Family Practice 2026;16(1):25-32
Legal risks and liability issues in medical practice serve as a primary catalyst for the current collapse of essential healthcare services in Korea. Currently, medical disputes in Korea are disproportionately focused on criminal prosecutions and high-damages civil litigation. This punitive approach fosters a culture of concealment, encourages defensive medicine, and accelerates the exodus of medical professionals from essential fields. Ultimately, this cycle deprives the system of opportunities for improvement and poses a significant threat to patient safety. In contrast, many advanced nations have adopted principles of “Just Culture” and “Safe Space,” prioritizing non-punitive reporting and systemic root-cause analysis over individual retribution. To address these issues, this paper proposes four key strategies: First, the establishment of an independent “Patient Safety Investigation Agency” to objectively investigate incidents and identify systemic flaws. Second, a transition from criminal punishment to licensing board-led management, focusing on re-education and counseling to maintain quality of care. Third, the enactment of “Apology Laws” to ensure that expressions of regret or apologies cannot be used as legal evidence of liability, thereby fostering trust and psychological recovery. Finally, the creation of a “Patient Safety Fund” to provide prompt and sufficient public compensation to victims regardless of proven negligence. In conclusion, it is imperative to shift the paradigm by defining medical accidents as “system failures” rather than individual faults. Strengthening the social safety net will encourage medical professionals to return to essential care and build a sustainable healthcare environment centered on patient safety.
6.Beyond the Dual Control Tower: Directions for Reforming the National Emergency Medical System to Enhance Patient Safety and Ensure Continuity in South Korea
Eun Kyung EO ; Heejun SHIN ; HaDa RYUOK ; Hee Gyung KANG ; Sung-ju KIM ; Eunyoung CHO ; Eun Jin HA ; Juhwan OH ; Mihwa YOO
Korean Journal of Family Practice 2026;16(1):17-24
Recurrent difficulty securing emergency department (ED) acceptance and delayed interfacility transfer, often resulting in multiple sequential transfer attempts (“round-robin” hospital seeking), in the Republic of Korea reflect a patient safety failure across the emergency care continuum, spanning Emergency Medical Services from emergency calls and prehospital care to ED stabilization, definitive treatment, and secondary transfer. We argue that the governance split between the National Fire Agency–led prehospital response and the Ministry of Health and Welfare–led emergency medical system fragments accountability and data, undermining sustainable quality management. We describe a “double bind” in which clinicians face medico-legal risk regardless of acceptance decisions, distorting transfer behavior. We propose an outcome-linked Quality Improvement system—integrated metrics, interoperable data linkage, operational medical control, and routine feedback—to strengthen Continuity of Patient Care. This requires functional integration of the dual command structure; transferring ambulance service functions to the Ministry of Health and Welfare, or an equivalently strong joint-governance model, should be evaluated. Regionally, responsibility-based systems should be implemented through councils that set transfer principles and resource allocation, supported by stable financing and performance review, with the regional emergency medical situation room providing medical control and real-time coordination. For mass-casualty incidents, preparedness should align standardized triage, integrated command and communication, training, and after-action review. Legal reform is a necessary starting point, but trust and sustained patient safety depend more on cultivating a learning-oriented safety culture grounded in patient experience and public deliberation throughout policy design and implementation.
7.What Should Be Done Right Now for Better Health System in 10 Years?: Health System Reform Tasks
Juhwan OH ; Sang-il LEE ; Kunhee PARK ; Seung-Won OH ; Junghee AHN ; HaDa RYUOK ; Eun Jin HA ; Seung-yeon CHO ; Sung-ju KIM ; Eunyoung CHO ; Hee Gyung KANG ; Serng Bai PAK ; Eun Kyung EO
Korean Journal of Family Practice 2026;16(1):1-8
South Korea’s current healthcare system stands at a critical crossroads that will determine whether it can progress in a better direction over the next decade. Behind the relatively stable level of population health that has been maintained until now, it has become clear that the deterioration of patient experiences, the risk of collapse in critical emergency medical services, the burnout of healthcare providers, and the crisis in the sustainability of healthcare finances have all accumulated simultaneously. This crisis can no longer be overcome by partial fixes or short-term measures alone. The answer to what needs to change first must begin with a reaffirmation of what the healthcare system should aim for. Ultimately, what needs to be changed now is not an individual policy, but the criteria and priorities through which we view healthcare. The focus must shift from what to provide more of, to questioning what holds greater social value. If such a shift does not begin now, in ten years we won’t face a better healthcare system, but care enmeshed in a deeper crisis. Now is precisely the time to fundamentally define the direction of the healthcare system.
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.Detection Ability of Quality of Life Changes and Responsiveness of the KOQUSS-40 and the EORTC QLQ-C30/STO22 in Patients Who Underwent Gastrectomy: A Prospective Comparative Study
Bang Wool EOM ; Keun Won RYU ; Ji Yeong AN ; Yun-Suhk SUH ; In CHO ; Sung Geun KIM ; Ji-Ho PARK ; Hoon HUR ; Hyung-Ho KIM ; Sang-Hoon AHN ; Sun-Hwi HWANG ; Hong Man YOON ; Ki Bum PARK ; Hyoung-Il KIM ; In-Gyu KWON ; Han-Kwang YANG ; Byoung-Jo SUH ; Sang-Ho JEONG ; Tae-Han KIM ; Oh Kyoung KWON ; Hye-Seong AHN ; Ji Yeon PARK ; Ki Young YOON ; Myoung Won SON ; Seong-Ho KONG ; Young-Gil SON ; Geum Jong SONG ; Jong Hyuk YUN ; Jung-Min BAE ; Do Joong PARK ; Sol LEE ; Jun-Young YANG ; Kyung Won SEO ; You-Jin JANG ; So Hyun KANG ; Joongyub LEE ; Hyuk-Joon LEE ;
Cancer Research and Treatment 2026;58(1):221-231
Purpose:
The aim of this study is to compare the detection ability of quality of life (QoL) changes and responsiveness of the KOrean QUality of life in Stomach cancer patients Study group (KOQUSS)-40 and European Organization for Research and Treatment of Cancer Quality of Life Questionnaire (EORTC QLQ).
Materials and Methods:
A multicenter prospective observational study was conducted to evaluate QoL changes after various gastrectomies between January 2021 and April 2022. Participants were instructed to complete the KOQUSS-40 and EORTC QLQ-C30/STO22 preoperatively and at 1, 3, 6, and 12 months postoperatively. QoL changes over time and QoL responsiveness were assessed for each questionnaire.
Results:
Data from 491 patients who underwent curative gastrectomy for gastric cancer at 22 institutions were analyzed. The summary scores of the KOQUSS-40 and EORTC QLQ-STO22 showed significant differences between the total and proximal gastrectomy groups (p=0.044 and p=0.038, respectively), but no difference was observed for the EORTC QLQ-C30. Dysphagia on the KOQUSS-40 was significantly different between the total and proximal gastrectomy groups (p=0.031); however, dysphagia on the EORTC QLQ-STO22 did not differ. The responsiveness of the KOQUSS-40 was similar to that of the EORTC QLQ in patients who experienced ≥ 10% body weight loss, but approximately 10% less in patients receiving adjuvant chemotherapy than the EORTC QLQ.
Conclusion
KOQUSS-40 has several advantages over EORTC QLQ-C30/STO22 when comparing QoL between the total and proximal gastrectomy groups. The findings provide information for researchers investigating the QoL of patients who have undergone curative gastrectomy for gastric cancer.
10.Survival Rates of Patients with Gastric Cancer According to Age and Sex: A Large-Scale Study Using Data from 14,739 Patients
Yonghoon CHOI ; Nayoung KIM ; Ji Hyun KIM ; Hyeong Ho JO ; Hyeon Jeong OH ; Hye Seung LEE ; Yu Kyung JUN ; Hyuk YOON ; Cheol Min SHIN ; Young Soo PARK ; Dong Ho LEE ; So Hyun KANG ; Young Suk PARK ; Sang-Hoon AHN ; Yun-Suhk SUH ; Do Joong PARK ; Hyung Ho KIM ; Ji-Won KIM ; Jin Won KIM ; Keun-Wook LEE ; Won CHANG ; Yoon Jin LEE ; Kyoung Ho LEE ; Young Hoon KIM
Cancer Research and Treatment 2026;58(1):252-263
Purpose:
The male predominance in the incidence of gastric cancer (GC) is established; however, sex differences in the prognosis of GC remain controversial. As such, this study analyzed the prognosis of patients with GC based on age and sex.
Materials and Methods:
Data from 14,739 patients diagnosed with GC at Seoul National University Bundang Hospital between 2003 and 2023 were analyzed. Baseline characteristics, histological types of GC, overall and GC-specific survival rates (age and stage stratification), and associated risk factors were analyzed.
Results:
Females were significantly younger (p < 0.001) and exhibited more gastric body cancers (p < 0.001) and tumors with diffuse-type or poorly differentiated histology (p < 0.001) than males. Females exhibited an advantage over males in terms of overall survival (p=0.004), but not in GC-specific survival. However, age stratification revealed significant sex differences, that females < 50 years of age exhibited survival disadvantages (p < 0.001); however, this trend was reversed with age, and females > 60 years exhibited survival advantages (p < 0.001) for both overall and GC-specific survival. This may be explained by the lower ratio of diffuse-type GC as females age. Furthermore, in the analysis according to stage, females with stage IV disease exhibited significant survival disadvantages, with significantly younger age and a higher proportion of diffuse-type GC which exhibits aggressive features, resulting in poorer survival than in males.
Conclusion
Age and stage stratification revealed significant differences in survival between the sexes, which can be helpful for public health strategies.

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