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.

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.

Background: s/Aims: Reported incidence of extrahepatic bile duct cancer is higher in Asians than in Western populations. Korea, in particular, is one of the countries with the highest incidence rates of extrahepatic bile duct cancer in the world. Although research and innovative therapeutic modalities for extrahepatic bile duct cancer are emerging, clinical guidelines are currently unavailable in Korea. The Korean Society of Hepato-Biliary-Pancreatic Surgery in collaboration with related societies (Korean Pancreatic and Biliary Surgery Society, Korean Society of Abdominal Radiology, Korean Society of Medical Oncology, Korean Society of Radiation Oncology, Korean Society of Pathologists, and Korean Society of Nuclear Medicine) decided to establish clinical guideline for extrahepatic bile duct cancer in June 2021. Methods: Contents of the guidelines were developed through subgroup meetings for each key question and a preliminary draft was finalized through a Clinical Guidelines Committee workshop. Results: In November 2021, the finalized draft was presented for public scrutiny during a formal hearing. Conclusions The extrahepatic guideline committee believed that this guideline could be helpful in the treatment of patients.

This study was conducted to investigate potential differences in vaccine efficacy between patients undergoing palliative chemotherapy and receiving adjuvant chemotherapy. Additionally, the study proved the influence of vaccination timing on vaccine efficacy during active chemotherapy. Anti-receptor-binding domain (RBD) IgG binding antibody assays and surrogate neutralizing antibody assays were performed after BNT162b2 or mRNA-1273 vaccination in 45 solid cancer patients (23 adjuvant and 22 palliative chemotherapy) and in 24 healthy controls before vaccination (baseline), at every two to four weeks after the first (post-dose 1) and the second vaccination (post-dose 2). The levels of anti-RBD IgG and neutralizing antibodies increased significantly from baseline through post-dose 1 to post-dose 2 in all three groups. At the post-dose 1, the anti-RBD IgG and neutralizing antibody levels were significantly lower in cancer patients than in healthy controls. However, by post-dose 2, the seropositivity of anti-RBD IgG and neutralizing antibodies uniformly reached 100% across all groups, with no significant disparity in antibody levels among the three groups. Moreover, the antibody titers were not significantly different between patients with a vaccine and chemotherapy interval of more than 14 days or those with less than 14 days. This study demonstrated that after second doses of mRNA COVID-19 vaccines, humoral immune responses in patients receiving chemotherapy were comparable to those of healthy controls, regardless of whether the purpose of the anti-cancer treatment was palliative or adjuvant. Furthermore, the timing of vaccination did not affect the level of humoral immunity after the second vaccination.

While the guidelines for adjuvant chemotherapy (AC) for colon cancer are relatively standardized, those for early rectal cancer are still lacking. We therefore evaluated the role of AC in clinical stage II rectal cancer treatment after preoperative chemoradiotherapy (CRT). Patients diagnosed with early rectal cancer (defined by clinical stage T3/4, N0) who completed CRT followed by surgery were enrolled in this retrospective study. To evaluate the role of AC, we analyzed the risk of recurrence and survival based on clinicopathologic parameters and adjuvant chemotherapy. Of the 112 patients, 11 patients (9.8%) experienced recurrence and five patients (4.8%) died. In a multivariate analysis, circumferential resection margin involvement (CRM+) on magnetic resonance imaging at diagnosis, CRM involvement following neoadjuvant therapy (ypCRM+), tumor regression grade (≤G1) and no-AC were considered poor prognostic factors for recurrence free survival (RFS). In addition, ypCRM+ and no-AC were associated with poor overall survival (OS) in the multivariate analysis. AC including 5-FU monotherapy demonstrated the benefits of reduced recurrence and prolonged survival in clinical stage II rectal cancer, even in pathologic stage following neoadjuvant therapy (ypStage) 0-I. Further prospective studies are needed to verify the benefit of each regimen of AC and the development of a method that can accurately predict CRM status before surgery, and a vigorous treatment that can induce CRM non-involvement (CRM−) should be considered even in early stages of rectal cancer.

Cholesterol (CL) is required for various biomolecular production processes, including those of cell membrane components. Therefore, to meet these needs, CL is converted into various derivatives. Among these derivatives is cholesterol sulfate (CS), a naturally produced CL derivative by the sulfotransferase family 2B1 (SULT2B1), which is widely present in human plasma. CS is involved in cell membrane stabilization, blood clotting, keratinocyte differentiation, and TCR nanocluster deformation. This study shows that treatment of T cells with CS resulted in the decreased surface expression of some surface T-cell proteins and reduced IL-2 release. Furthermore, T cells treated with CS significantly reduced lipid raft contents and membrane CLs. Surprisingly, using the electron microscope, we also observed that CS led to the disruption of T-cell microvilli, releasing small microvilli particles containing TCRs and other microvillar proteins. However, in vivo, T cells with CS showed aberrant migration to high endothelial venules and limited infiltrating splenic T-cell zones compared with the untreated T cells. Additionally, we observed significant alleviation of atopic dermatitis in mice injected with CS in the animal model. Based on these results, we conclude that CS is an immunosuppressive natural lipid that impairs TCR signaling by disrupting microvillar function in T cells, suggesting its usefulness as a therapeutic agent for alleviating T-cellmediated hypersensitivity and a potential target for treating autoimmune diseases.

Background/Aims: Despite the increasing need for geriatric assessment prior to chemotherapy, the method for this assessment remains inadequate for older cancer patients. We aimed to propose a simple assessment method to predict the performance of adjuvant chemotherapy in older patients after colon cancer surgery. Methods: This prospective study included patients over 65 years of age who were scheduled for adjuvant chemotherapy after colon cancer surgery. Before initiating chemotherapy, their functional status was assessed on the basis of activities of daily living (ADL)/instrumental activities of daily living (IADL). These parameters were analyzed with clinical characteristics and the patterns of adjuvant chemotherapy. The focus was on the completion rate of adjuvant chemotherapy. Results: A total of 89 patients with a median age of 72 years were analyzed. Among them, 54 (61%) were non-impaired and 35 (39%) were impaired regarding their ADL/IADL classification. Low body mass index and impairment of ADL/IADLs were significantly associated with chemotherapy interruption. Among toxicities, fatigue and hand-foot syndrome were independent prognostic factors for chemotherapy interruption. Impairments of ADL/IADL were significantly associated with fatigue regardless of age. Based on age and ADL/IADL stratification, younger patients (≤ 72 years) and/or those who were ADL/IADL non-impaired were significantly more likely to complete adjuvant chemotherapy than older patients (> 72 years) and ADL/IADL impaired patients (p = 0.038). This was regardless of the chemotherapy regimen. Conclusions Functional assessment using ADL/IADL is a convenient method to predict chemotherapy toxicity and performance. These results suggested that routine screening for ADL/IADLs could guide appropriate patient selection for the completion of adjuvant chemotherapy and predict expected outcomes.

This study aimed to investigate the frequency of dental visits after coronavirus disease 2019 (COVID-19) in children and adolescents in comparison to that of adults. The data on the number of dental visits on the basis of different classification and treatment codes for all the age groups were provided by the Health Insurance Review and Assessment Service from January 2017 to December 2020. To reduce the impact of the population change, dental visits per 1000 people was used. After the start of the pandemic, dental visits per 1000 people decreased in all age groups when analyzed for the diseases of pulp and periapical tissues classification code and dental visits per 1000 people decreased over 5 years age groups when analyzed for the pulp treatment code. Regarding the restorative treatment code, visits in the 0 - 19 years age group decreased after the pandemic. Based on the comparison of the number of confirmed COVID-19 cases to that of monthly dental visits by treatment codes, the change rate of pulp and restorative treatments gradually decreased after the waves of the pandemic in February and August 2020 in Korea. Furthermore, dental visits per 1000 people for gingivitis and periodontal disease classification code increased after the pandemic in all age groups. The rate of decrease in dental visits per 1000 people for restorative treatments in children and adolescents was higher than that in adults. The rate of decrease in the number of dental visits for multi-visit pulp treatments showed a rapid decrease as compared to that of 1-visit pulp treatments after the pandemic. This study identified changes in the number of dental visits of children and adolescents after COVID-19 transmission in comparison to that observed in adults.

Background and Objectives: Airway reconstruction surgery in children is still challenging, especially in cases of combined subglottic and posterior glottic stenosis (PGS). The aim of this study was to review the underlying reasons of failure in open airway reconstruction surgeries performed for children with combined subglottic and PGS.Subjects and Method We reviewed medical records of seven children who received more than two open airway reconstruction surgeries to finally achieve and maintain decannulation status for more than one year. Twenty-two reconstructive surgeries were performed and they consisted of 19 laryngotracheal reconstruction (LTR), 2 cricotracheal resection with end-toend anastomosis (CTR) and one extended CTR. For each patient, the following potential causes of failure were evaluated; preoperative evaluation (PE), type of reconstruction (TR), single vs. double staging (SDS), type of stent (TS), and perioperative optimization (PO). Results: The median age of patients at the time of surgery was 32 months (range, 4-64 months). Successful decannulation was achieved after the median open surgery of three (range, 2-5 times for each patient). Recognized causes of failure were as follows: 8 insufficient PE, 10 inadequate TR, 3 improper SDS, 8 ill-chosen TS, and 2 inappropriate PO. Conclusion PE of dynamic airway is important, especially vocal fold mobility and tracheomalacia. Types of reconstruction should be carefully decided after full consideration of potential causes of failure, and adequate laryngotracheal stent is essential.

Extra-pulmonary neuroendocrine carcinoma is a rare and aggressive cancer. Although several biological and histological markers have been suggested as prognostic factors for this cancer, the prognostic importance of systemic inflammatory markers, including the neutrophil-lymphocyte ratio and platelet-lymphocyte ratio, is unclear. This study aimed to evaluate the association between systemic inflammatory markers and the prognosis of extra-pulmonary neuroendocrine carcinoma. We retrospectively analyzed the clinical data of 85 patients with unresectable or metastatic extra-pulmonary neuroendocrine carcinoma who received platinum-based chemotherapy as first-line chemotherapy from August 2007 to November 2019. We used time-dependent receiver operating characteristic curve analysis to determine the cut-off values. The cut-off values for the neutrophil-lymphocyte ratio and platelet-lymphocyte ratio were 3.0 and 158.5, respectively. There was no significant difference in the Eastern Cooperative Oncology Group performance status score, Ki-67 index, or response to chemotherapy between groups. The high neutrophil-lymphocyte ratio group showed significantly worse overall survival (high vs. low, median 11.1 vs. 21.0 months, log-rank p=0.004) and shorter median progression-free survival, but the latter was not statistically significant. The high platelet-lymphocyte ratio group also showed significantly worse progression-free survival and overall survival than the low platelet-lymphocyte ratio group (high vs. low:median 5.6 vs. 9.8 months, log-rank p=0.047 and median 13.8 vs. 21.0 months, log-rank p=0.013, respectively). In multivariable analysis, a high neutrophil-lymphocyte ratio was an independent prognostic factor for overall survival. The neutrophil-lymphocyte ratio is a potent and readily available prognostic factor for extra-pulmonary neuroendocrine carcinoma.