1.Impact of Tumor Bilaterality and Multifocality in Predicting Recurrence of Papillary Thyroid Carcinoma: A Retrospective Cohort Study
Eunji KIM ; Jun Hyun PARK ; Ji-Young PARK ; Jin Hyang JUNG ; Sang-Woo LEE
Endocrinology and Metabolism 2026;41(2):288-299
Background:
This study investigated the prognostic value of bilaterality and multifocality in papillary thyroid carcinoma (PTC) recurrence, aiming to inform optimal surgical strategies.
Methods:
In this retrospective cohort, 1,966 patients who underwent total thyroidectomy for PTC (2011–2014) were categorized into four groups according to tumor multifocality and bilaterality confirmed by postoperative histopathology: group 1, unilateral solitary; group 2, unilateral multifocal; group 3, bilateral solitary; group 4, bilateral multifocal. Clinicopathologic features and clinical outcomes were compared across these groups.
Results:
Group 4 exhibited the highest prevalence of BRAFV600E positivity, nodal metastases, and recurrence. Both bilaterality and multifocality were associated with more aggressive clinicopathologic characteristics. Recurrence risk increased with the number of tumor foci, with the odds ratio (OR) significantly elevated for more than five foci. Satellite pattern was strongly linked to recurrence (OR, 19.49; P<0.001). While tumor multifocality (≥5 foci) and bilaterality were associated with recurrence in univariate analyses, these associations were not independent after adjustment. Kaplan-Meier analysis demonstrated the lowest recurrence-free survival (RFS) in group 4. Patients with bilateral disease had significantly lower RFS than those with unilateral disease (P=0.003), whereas multifocality did not significantly affect RFS compared to solitary disease (P=0.095).
Conclusion
Tumor bilaterality, multifocality (≥5 foci), and satellite pattern were associated with aggressive features and higher recurrence risk. Although not independent predictors, these factors may serve as useful surrogate markers of aggressive disease biology and help guide personalized surgical strategies in patients with PTC.
2.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.
3.Germline Mutations Related to Complete Remission After Neoadjuvant Chemotherapy in Patients With Triple-negative Breast Cancer
Jee Hyun AHN ; Ji Soo PARK ; Dongju WON ; Seung-Tae LEE ; Suk Jun LEE ; Seung Hye YANG ; Jee Ye KIM ; Seho PARK ; Seung Il KIM ; Byeong-Woo PARK ; Min Hwan KIM ; Gun Min KIM ; Joohyuk SOHN ; Hyung Seok PARK
Journal of Breast Cancer 2026;29(2):118-127
Purpose:
Triple-negative breast cancer (TNBC) is a frequent phenotype of BRCA-mutanttumors. Tumors with BRCAness may show characteristics of BRCA-mutant tumors and respond to similar treatments. Next-generation sequencing is an efficient and cost-effective method for simultaneously sequencing multiple cancer susceptibility genes, surpassing conventional Sanger testing.
Methods:
A total of 148 women with TNBC were recruited from December 2015 to November 2018, as part of a sub-analysis based on the PEARLY trial data. Of them, 103 patients received neoadjuvant chemotherapy (NCT). The targeted genes related to hereditary cancers were sequenced using the 65-gene germline next-generation sequencing (gNGS) panel pathogenic and likely pathogenic variants (P&LPs) were determined by Sanger sequencing. We examined the occurrence of pathologic complete remission (ypCR) in patients with P&LPs.
Results:
The patients’ median age was 47 years (range, 27–69 years). Twenty (13.7%) of 148 patients had P&LP in six genes, including BARD1 (n = 2), BRCA1 (n = 9), BRCA2 (n = 5), CHEK2 (n = 1), RAD51C (n = 1), and RAD51D (n = 2). Among the 103 patients with NCT, 43 (41.7%) achieved ypCR (P&LPs; 9 individuals vs. non-variants; 34 individuals). Among the 103 patients with NCT, 14 (9.3%) had P&LPs. Nine of 14 patients with P&LPs, including BARD1 (n = 2), BRCA1 (n = 4), BRCA2 (n = 1), RAD51C (n = 1), and RAD51D (n = 1), achieved ypCR, showing a trend toward statistical significance (p = 0.066).
Conclusion
Germline P&LP mutations in TNBC patients can be detected by gNGS. This panel test can identify BRCA and BRCAness mutations that may predict ypCR in TNBC.
4.Early Diagnostic Changes in Autism Spectrum Disorder: A Retrospective Study
Jung Sook YEOM ; Young-Soo KIM ; Ji Sook PARK ; Eun Sil PARK ; Ji-Hyun SEO ; Jae-Young LIM ; Hyang-Ok WOO
Annals of Child Neurology 2026;34(2):136-143
Purpose:
Autism spectrum disorder (ASD) exhibits heterogeneous developmental trajectories; however, longitudinal studies using the Korean Childhood Autism Rating Scale (K-CARS) are scarce. This study examined diagnostic changes and related developmental characteristics through repeated K-CARS assessments.
Methods:
We retrospectively reviewed the medical records of children who underwent repeated K-CARS assessments between May 2021 and December 2024 at Gyeongsang National University Hospital. Based on diagnostic status at the initial (T1) and follow-up (T2) evaluations, participants were classified as having persistent ASD (ASD at T1 and T2), emerging ASD (non-ASD at T1 but ASD at T2), or desisting ASD (ASD at T1 but non-ASD at T2). Developmental profiles were evaluated using the social quotient (SQ), visual-motor integration (VMI), and language quotients.
Results:
Forty-three children (32 boys; median age, 2.9 years at T1 and 4.3 years at T2) were included. Twenty-two met ASD criteria at T1, and 15 (68%) retained the diagnosis at T2. Across the cohort, 15 (35%) had persistent ASD, 21 (49%) had emerging ASD, and seven (16%) had desisting ASD. The desisting group showed higher baseline VMI and better outcomes at follow-up. The emerging group initially had higher SQ and VMI than the persistent group, but these differences disappeared over time. Higher baseline VMI was associated with desisting status and higher baseline SQ with emerging ASD (odds ratios, 3.14 and 2.59 per standard deviation increase, respectively; P=0.06 and P=0.07).
Conclusion
Early ASD diagnoses were generally stable yet variable, supporting repeated assessment. Baseline VMI and SQ may relate to later diagnostic changes.
5.The Korean Rectal Cancer Multidisciplinary Committee Clinical Practice Guidelines for Rectal Cancer version 2.0
Hyo Seon RYU ; Hyun Jung KIM ; Dong Hyun KANG ; Yoo-Kang KWAK ; Han Deok KWAK ; Yoon-Hye KWON ; Dalyon KIM ; Baek-Hui KIM ; Jae Hyun KIM ; Ji Hun KIM ; Jin Won KIM ; Tae Hyung KIM ; Hae Young KIM ; Soo Min NAM ; Gyoung Tae NOH ; Jun Woo BONG ; Nak Song SUNG ; Seon Hui SHIN ; Kil-Yong LEE ; Sung Chul LEE ; Sea-Won LEE ; Jung Won LEE ; Jong Min LEE ; Myung Hoon IHN ; Joo Han LIM ; Woong Bae JI ; Dae Hee PYO ; Young Ki HONG ; Jung-Myun KWAK ;
Annals of Coloproctology 2026;42(1):4-33
Rectal cancer, which accounts for approximately 40% of colorectal cancers, remains a major clinical concern. Recent advances in diagnostic imaging, surgical techniques, radiotherapy, and systemic treatment have steadily improved rectal cancer outcomes. Considering this, the Korean Rectal Cancer Multidisciplinary (KRCM) Committee has aimed to provide clinicians and policymakers with up-to-date, evidence-based clinical practice guidelines to support optimal decision-making, reflecting current evidence, the Korean healthcare context, and patient values and preferences. The Clinical Practice Guidelines for Rectal Cancer version 2.0 were developed through multidisciplinary collaboration with related academic societies, building upon and updating the KRCM Clinical Practice Guidelines version 1.0 (titled “Multidisciplinary guidelines for the management of rectal cancer”). These consensus guidelines of the KRCM were established based on a comprehensive literature review, evidence synthesis, with recommendation development guided by the GRADE (Grading of Recommendations Assessment, Development and Evaluation) methodology, and consideration of applicability in real-world clinical practice under the national health insurance system. Each recommendation has been presented with its strength and level of evidence.
6.Misinterpreted Recurrence of Autoimmune Pancreatitis as Malignant Transformation of Branch-Duct Intraductal Papillary Mucinous Neoplasm
Eun Jeong KIM ; Chang Hyun KIM ; Tae Seung LEE ; Jin Ho CHOI ; In Rae CHO ; Sang Hyub LEE ; Ji Kon RYU ; Woo Hyun PAIK
Korean Journal of Pancreas and Biliary Tract 2026;31(1):13-18
This case describes a male with a history of type 1 autoimmune pancreatitis (AIP) who had a concomitant branch-duct intraductal papillary mucinous neoplasm under long-term surveillance. During follow-up, new high-risk radiologic features developed within the pancreatic cyst, raising concern for malignant transformation and ultimately leading to surgical resection. However, final histopathologic examination revealed recurrent type 1 AIP rather than malignant progression of branch-duct intraductal papillary mucinous neoplasm, a finding that represents an uncommon and diagnostically challenging manifestation. This case suggests that when new imaging changes are observed during surveillance of pancreatic cystic lesions, clinicians should consider not only malignant transformation but also the possibility of recurrence or coexistence of underlying diseases such as AIP.
7.Evaluating the Accuracy and Diagnostic Reasoning of Multimodal Large Language Models in Interpreting Neuroradiology Cases From RadioGraphics
Pae Sun SUH ; Ji Su KO ; Woo Hyun SHIM ; Hwon HEO ; Chang-Yun WOO ; Hyungjun PARK ; Chong Hyun SUH
Korean Journal of Radiology 2026;27(3):214-226
Objective:
To evaluate the accuracy and reasoning capabilities of large multimodal language models compared with those of neuroradiology subspecialty-trained radiologists in neuroradiology case interpretation.
Materials and Methods:
This experimental study used custom-made 401 radiologic quizzes derived from articles published in RadioGraphics covering neuroradiology and head and neck topics (October 2020 to February 2024). We prompted the GPT-4 Turbo with Vision (GPT-4V), GPT-4 Omni, Gemini Flash, and Claude models to provide the top three differential diagnoses with a rationale and describe examination characteristics such as imaging modality, sequence, use of contrast, image plane, and body part. The temperature was adjusted to 0 and 1 (T1). Two neuroradiologists answered the same questions.The accuracies of the large language models (LLMs) and the neuroradiologists were compared using generalized estimating equations. Three neuroradiologists assessed the rationale provided by the LLMs for their differential diagnoses using four-point scales, separately for specific lesion locations and imaging findings, and evaluated the presence of hallucinations and the overall acceptability of the responses.
Results:
Top-3 accuracy (i.e., correct answers present among top-3 differential diagnoses) of LLMs ranged from 29.9% (120 of 401) to 49.4% (198 of 401, obtained with GPT-4V in the T1 setting), while radiologists achieved 80.3% (322 of 401) and 68.3% (274 of 401), respectively (P < 0.001). Regarding the rationale for differential diagnoses, GPT-4V (T1) accurately identified both the specific lesion location and imaging findings in 30.7% (123 of 401) and 12.9% (16 of 124) of cases without textual clinical history. Hallucinations occurred in 4.5% (18 of 401), and only 29.4% (118 of 401) of the LLM-generated analyses were deemed acceptable. GPT-4V (T1) demonstrated high accuracy in identifying the imaging modality (97.4% [800 of 821]) and scanned body parts (92.2% [756 of 820]).
Conclusion
LLMs remarkably underperformed compared with neuroradiologists and showed unsatisfactory reasoning for their differential diagnoses, with performance declining further in cases without textual input of clinical history. These findings highlight the limitations of current multimodal LLMs in neuroradiological interpretation and their reliance on text input.
9.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.
10.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.

Result Analysis
Print
Save
E-mail