Purpose: To develop the 2025 update to the Korean colorectal cancer (CRC) screening guidelines by systematically evaluating recent evidence, integrating domestic data, and addressing changes since the 2015 guideline revision, thereby providing an evidence-based standard for clinicians and policymakers. Methods: A multidisciplinary committee developed the guidelines using the Grading of Recommendations, Assessment, Development and Evaluation (GRADE) methodology. The process included formulation of three key questions addressing screening efficacy, diagnostic accuracy, and optimal screening age and interval. A systematic review of international guidelines and primary literature was conducted, yielding 327 eligible studies. In addition, a utility-based analysis using a Markov model was performed to determine optimal screening ages and intervals. Results: The evidence synthesis identified high-certainty evidence supporting the use of the fecal immunochemical test (FIT) for reducing CRC mortality and moderate-certainty evidence for colonoscopy. Evidence for computed tomographic colonography (CTC) and stool DNA testing was rated as very low certainty. Based on the evidence review and cost-utility analysis, the committee conditionally recommends CRC screening for asymptomatic, average-risk adults aged 45–74 years using either colonoscopy every 10 years or FIT every 1–2 years. CTC and stool DNA testing were not recommended owing to insufficient evidence. Conclusion The 2025 Korean Guidelines for Colorectal Cancer Screening present updated, evidence-based recommendations tailored to the domestic healthcare context. By conditionally endorsing both colonoscopy and FIT for individuals aged 45–74 years, these guidelines aim to improve population-level screening effectiveness and reduce the burden of CRC in South Korea.

Purpose: Glycated hemoglobin (HbA1c) as a glycemic index may have limited value in pediatric patients with acute leukemia as they often present with anemia and/or pancytopenia. To address this issue, we evaluated the usefulness of glycated albumin (GA) as a glycemic monitoring index in pediatric patients with acute leukemia. Methods: Medical records of 25 patients with type 2 diabetes mellitus (T2DM), 63 patients with acute leukemia, and 115 healthy children from Seoul St. Mary's Hospital, The Catholic University of Korea, were retrospectively investigated for serum GA, HbA1c, and fasting blood glucose (FBG) levels, along with demographic data. Results: GA, HbA1c, and FBG levels did not differ between the control and acute leukemia groups. In the T2DM group, positive correlations were observed among GA, HbA1c, and FBG (P<0.01). Although GA level was not associated with the HbA1c level in the control group, GA and HbA1c levels showed a positive correlation in the acute leukemia group (P=0.045). Regression analysis revealed GA and HbA1c levels to be positively correlated in the acute leukemia and T2DM groups even after adjusting for age, sex, and body mass index z-score (P=0.007, P<0.01). Conclusion GA may be a useful complementary parameter to HbA1c for glycemic monitoring in pediatric patients with acute leukemia, similar to its use in patients with T2DM.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objectives: . Balloon dilation of the Eustachian tube (BDET) is widely recognized as a minimally invasive treatment for obstructive Eustachian tube dysfunction (ETD). We employed a Delphi consensus methodology to develop recommendations for the clinical management of BDET in cases of obstructive ETD. Methods: . A Delphi panel consisting of 26 expert physicians specializing in otology participated in two rounds of anonymous, iterative questionnaires. Consensus was defined as agreement from ≥70% of the panelists on a recommendation, while disagreement was defined as <70% agreement. The responses from the Delphi study were analyzed using both the content validity ratio and Kendall’s coefficient of concordance. Results: . The panel finally evaluated 26 topics, reaching agreement on 9 and failing to reach consensus on 17 after two rounds. While consensus was not achieved regarding the postoperative follow-up period, a duration of 12 months was most commonly adopted. The Valsalva maneuver and questionnaire responses were identified as the most agreed-upon postoperative assessment tools following BDET. Conclusion . Consensus was reached on several recommendations for managing BEDT in obstructive ETD. This agreement will guide future research aimed at defining standard postoperative management for BEDT.

Objective: : Chronic subdural hematomas (cSDHs) are generally known to result from traumatic tears of bridging veins. However, the causes of repeat spontaneous cSDHs are still unclear. We investigated the changes in vasculature in the human dura mater and outer membrane (OM) of cSDHs to elucidate the cause of their spontaneous repetition. Methods: : The dura mater was obtained from a normal control participant and a patient with repeat spontaneous cSDHs. The pathological samples from the patient included the dura mater and OM tightly adhered to the inner dura. The samples were analyzed with a particular focus on blood and lymphatic vessels by immunohistochemistry, 3-dimensional imaging using a transparent tissue clearing technique, and electron microscopy. Results: : The dural border cell (DBC) layer of the dura mater and OM were histologically indistinguishable. There were 5.9 times more blood vessels per unit volume of tissue in the DBC layer and OM in the patient than in the normal control. The DBC layer and OM contained pathological sinusoidal capillaries not observed in the normal tissue; these capillaries were connected to the middle meningeal arteries via penetrating arteries. In addition, marked lymphangiogenesis in the periosteal and meningeal layers was observed in the patient with cSDHs. Conclusion : Neovascularization in the OM seemed to originate from the DBC layer; this is a potential cause of repeat spontaneous cSDHs. Embolization of the meningeal arteries to interrupt the blood supply to pathological capillaries via penetrating arteries may be an effective treatment option.

Background: and Purpose In young patients (aged 18–60 years) with patent foramen ovale (PFO)- associated stroke, percutaneous closure has been found to be useful for preventing recurrent ischemic stroke or transient ischemic attack (TIA). However, it remains unknown whether PFO closure is also beneficial in older patients. Methods: Patients aged ≥60 years who had a cryptogenic stroke and PFO from ten hospitals in South Korea were included. The effect of PFO closure plus medical therapy over medical therapy alone was assessed by a propensity-score matching method in the overall cohort and in those with a high-risk PFO, characterized by the presence of an atrial septal aneurysm or a large shunt. Results: Out of the 437 patients (mean age, 68.1), 303 (69%) had a high-risk PFO and 161 (37%) patients underwent PFO closure. Over a median follow-up of 3.9 years, recurrent ischemic stroke or TIA developed in 64 (14.6%) patients. In the propensity score-matched cohort of the overall patients (130 pairs), PFO closure was associated with a significantly lower risk of a composite of ischemic stroke or TIA (hazard ratio [HR]: 0.45; 95% confidence interval [CI]: 0.24–0.84; P=0.012), but not for ischemic stroke. In a subgroup analysis of confined to the high-risk PFO patients (116 pairs), PFO closure was associated with significantly lower risks of both the composite of ischemic stroke or TIA (HR: 0.40; 95% CI: 0.21–0.77; P=0.006) and ischemic stroke (HR: 0.47; 95% CI: 0.23–0.95; P=0.035). Conclusion Elderly patients with cryptogenic stroke and PFO have a high recurrence rate of ischemic stroke or TIA, which may be significantly reduced by device closure.

Purpose: We conducted a nationwide, multicenter, prospective registry study for newly diagnosed patients with peripheral T-cell lymphoma (PTCL) to better define the clinical characteristics, treatment patterns, survival outcomes, and the role of upfront autologous stem cell transplantation (ASCT) in these patients. Materials and Methods: Patients with PTCL receiving chemotherapy with curative intent were registered and prospectively monitored. All patients were pathologically diagnosed with PTCL. Results: A total of 191 patients with PTCL were enrolled in this prospective registry study. PTCL, not otherwise specified (PTCL-NOS) was the most common pathologic subtype (n=80, 41.9%), followed by angioimmunoblastic T-cell lymphoma (AITL) (n=60, 31.4%). With a median follow-up duration of 3.9 years, the 3-year progression-free survival (PFS) and overall survival (OS) rates were 39.5% and 60.4%, respectively. The role of upfront ASCT was evaluated in patients who were considered transplant-eligible (n=59). ASCT was performed as an upfront consolidative treatment in 32 (54.2%) of these patients. There were no significant differences in PFS and OS between the ASCT and non-ASCT groups for all patients (n=59) and for patients with PTCL-NOS (n=26). However, in patients with AITL, the ASCT group was associated with significantly better PFS than the non-ASCT group, although there was no significant difference in OS. Conclusion The current study demonstrated that the survival outcomes with the current treatment options remain poor for patients with PTCL-NOS. Upfront ASCT may provide a survival benefit for patients with AITL, but not PTCL-NOS.

Purpose: A three-drug combination of cyclophosphamide, bortezomib, and dexamethasone (CVD) shows significant efficacy and manageable toxicity as induction therapy in patients with multiple myeloma. Materials and Methods: In this phase II study, we enrolled 45 patients who achieved a very good partial response (VGPR) or partial response (PR) after autologous stem cell transplantation (ASCT) and evaluated the efficacy and toxicity of CVD consolidation. CVD consolidation comprised three cycles of cyclophosphamide 300 mg/m2 orally on days 1, 8, and 15, and bortezomib 1.3 mg/m2 subcutaneously on days 1, 8, 15, and 22, along with dexamethasone 20 mg orally or intravenously on days 1 and 2, 8 and 9, 15 and 16, and 22 and 23. Results: At enrollment, 39 patients (86.7%) showed VGPR, and nine (13.3%) presented with PR. Nineteen patients (45.2%) achieved a complete response or better as their best response after the end of consolidation. Overall, 22 of 42 patients (52.4%) experienced an improved response status with CVD consolidation. Three-year overall survival and progression-free survival rates were 89.0% and 42.7%, respectively. The most common non-hematologic toxicities were peripheral neuropathy and infection (20.5%), with no grade ≥ 3 neuropathy observed. Conclusion These results showed that CVD consolidation therapy improved the response with reasonable toxicity in patients with residual disease after ASCT. This trial was registered with the Clinical Research Information Service, Republic of Korea (KCT0001327).

Purpose: This phase II, open-label, multicenter study aimed to investigate the efficacy and safety of a rituximab intensification for the 1st cycle with every 21-day of rituximab, cyclophosphamide, doxorubicin, vincristine, and prednisolone (R-CHOP-21) among patients with previously untreated advanced-stage or bulky diffuse large B-cell lymphoma (DLBCL). Materials and Methods: Ninety-two patients with stage III/IV or bulky DLBCL from 21 institutions were administered 8 cycles of R-CHOP-21 with an additional one dose of rituximab intensification on day 0 of the 1st cycle (RR-CHOP). The primary endpoint was a complete response (CR) rate after 3 cycles of chemotherapy. Results: Among the 92 DLBCL patients assessed herein, the response rate after 3 cycles of chemotherapy was 88.0% (38.0% CR+50.0% partial response [PR]). After the completion of 8 cycles of chemotherapy, the overall response rate was observed for 68.4% (58.7% CR+9.8% PR). The 3-year progression-free survival rate was 64.0%, and the 3-year overall survival rate was 70.4%. Febrile neutropenia was one of the most frequent grade 3 adverse events (40.0%) and 5 treatment-related deaths occurred. Compared with the clinical outcomes of patients who received R-CHOP chemotherapy as a historical control, the interim CR rate was higher in male patients with RR-CHOP (20.5% vs. 48.8%, p=0.016). Conclusion Rituximab intensification on days 0 to the 1st cycle of the standard 8 cycles R-CHOP-21 for advanced DLBCL yielded favorable response rates after the 3 cycles of chemotherapy and acceptable toxicities, especially for male patients. ClinicalTrials.gov ID: NCT01054781.