Purpose: This 6-year post-marketing surveillance (PMS) study was conducted in South Korea to evaluate the real-world safety and effectiveness of eribulin in patients with advanced or metastatic breast cancer previously treated with anthracyclines and taxanes. Materials and Methods: During the study period (17 August 2012 to 16 August 2018), case-report files (CRFs) of patients receiving eribulin were collected. The main study endpoint was to assess the safety of eribulin. Evaluation of the effectiveness of eribulin was an exploratory endpoint. Patients were followed for 1 year after eribulin initiation. Results: CRFs were collected from 64 investigators at 64 sites for 1,079 patients. The safety analysis set (SAS) included 1,001 eribulin recipients; effectiveness was assessed in 244 patients. In the SAS, patients were predominantly female (99.6%), with a median age of 53.0 years, and diagnosed with metastatic breast cancer (92.0%). Eribulin was administered as a median 4th line chemotherapy. A total of 2,124 treatment-emergent adverse events (TEAEs) were reported in 661 patients (66.0%). Neutropenia was the most common TEAE (32.5% of patients), occurring at a median of 9-11 days from initial eribulin administration. Overall response and disease control rates were 31.7% and 95.6%, respectively, and the median duration of eribulin use (time to treatment failure) was 3.0 months. Conclusion This large real-world PMS analysis in patients with advanced or metastatic breast cancer demonstrated the effectiveness of eribulin and found no new safety concerns relative to safety information from prior clinical and real-world studies, and approvals in South Korea and other countries.

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.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.

Background: and Purpose The pain lateralization in cluster headache (CH) may be related to the asymmetry in the functions of the brain hemispheres. The right-sided dominance of pain in CH has been found inconsistently across studies, and so we aimed to characterize this and identify the factors influencing pain lateralization during current and previous bouts. Methods: This study enrolled 227 patients from the Korean Cluster Headache Registry between October 2018 and December 2020. We evaluated the side of pain during current and previous bouts, demographic features, and clinical characteristics, including handedness. Multivariable logistic regression analyses were performed to identify factors associated with the side of pain. Results: The 227 patients with CH included 131 (57.7%) with right-sided pain and 86 (37.9%) with left-sided pain during the current bout (p<0.001). The 189 patients with previous bouts of CH included 86.8% who consistently reported the same side of pain throughout multiple bouts (side-locked pain), with a higher prevalence of pain on the right than the left side (55.0% vs. 31.7%, p<0.001). Multivariable analyses revealed that higher age at diagnosis (odds ratio [OR]=1.045, p=0.031) and shorter CH attacks (OR=0.992, p=0.017) were associated with left-side-locked pain. However, handedness was not associated with the lateralization of leftside-locked pain. Conclusions This study has confirmed the predominance of right-sided pain throughout multiple CH bouts. We found that higher age at diagnosis and shorter CH attacks were associated with left-side-locked pain, suggesting that certain clinical factors are associated with the pain laterality. However, the underlying mechanisms linking these factors to lateralized pain remain unclear and therefore require further investigation.

Purpose: This study introduced adenomas per polypectomy (APP) as a novel metric for evaluating the progression of lesion discrimination skills among colonoscopy trainees. Methods: This retrospective study was conducted at the National Cancer Center, Korea between March 2020 and February 2023. Nine colorectal surgeons who completed a structured 1-year colonoscopy training program were included, and their performance was compared with that of 5 expert endoscopists. APP was defined as the number of histologically confirmed adenomas among the total number of polypectomies performed. The APPs were calculated serially to assess changes from the beginning to the end of the training. Results: A total of 8,072 colonoscopies were performed by 9 trainees and 11,687 by 5 experts. The average APP of the 9 trainees was 67.0%, which was significantly different from the 73.9% APP of the experts (P < 0.001). The APP progression of trainees exhibited 3 phases: phase 1 (<200 cases) showed increasing polyp detection and APP; phase 2 (200–500 cases) displayed a sharp rise in the number of polypectomies but a decline in APP; and phase 3 (>500 cases) demonstrated a decrease in the number of polypectomies with a moderate rise in APP. However, even in phase 3, the trainees’ APP remained significantly lower than that of the experts (69.9% vs. 73.9%, P = 0.027). Conclusion APP, a measure of visual adenoma discrimination ability, undergoes 3 stages of progression during colonoscopy training. This progression suggests that the APP may serve as an additional metric for assessing the effectiveness of colonoscopy training.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: To analyze adenoma detection rate (ADR) and related quality indicators of colonoscopy among trainees and make recommendations for appropriate colonoscopy training. Methods: ADR and related indicators of colonoscopies performed by 3 trainees and 5 colonoscopy experts between March and November 2022 were analyzed. These indicators were analyzed in both the entire patients and the screening/surveillance group. In addition, the training period of the 3 trainees was divided into 3 sections, and the changes in these indicators were examined. Results: The mean ADR of the 3 trainees was 50.6%. In the screening/surveillance group, the mean ADR of the 3 trainees was 51.8%, showing no significant difference from the experts' ADR (53.4%). When the training period was divided into 3 sections and analyzed in the screening/surveillance group, the mean ADR of the trainees gradually increased to 49.4%, 52.6%, and 53.6%, respectively; however, the difference was insignificant. Analyzing each trainee’s ADR, there was a significant difference among the 3 trainees (58.5% vs. 44.7% vs. 50.2%, P=0.008). However, in the third section of the training period, the 3 trainees’ ADRs were 53.0%, 49.2%, and 57.3%, respectively, showing no significant difference (P=0.606). Conclusion In the early stages of training, the ADR was higher than recommended; however, there were variances in ADR between individuals. As the training period passed, the ADR became similar at the expert level, whereas the difference in ADR between trainees decreased. Therefore, efforts to increase ADR should be made actively from the beginning of training and continued during the training period.

Purpose: This study aimed to evaluate the long-term clinical outcomes based on the ligation level of the inferior mesenteric artery (IMA) in patients with rectal cancer. Methods: This was a retrospective analysis of a prospectively collected database that included all patients who underwent elective low anterior resection for rectal cancer between January 2013 and December 2019. The clinical outcomes included oncological outcomes, postoperative complications, and functional outcomes. The oncological outcomes included overall survival (OS) and relapse-free survival (RFS). The functional outcomes, including defecatory and urogenital functions, were analyzed using the Fecal Incontinence Severity Index, International Prostate Symptom Score, and International Index of Erectile Function questionnaires. Results: In total, 545 patients were included in the analysis. Of these, 244 patients underwent high ligation (HL), whereas 301 underwent low ligation (LL). The tumor size was larger in the HL group than in the LL group. The number of harvested lymph nodes (LNs) was higher in the HL group than in the LL group. There were no significant differences in complication rates and recurrence patterns between the groups. There were no significant differences in 5-year RFS and OS between the groups. Cox regression analysis revealed that the ligation level (HL vs. LL) was not a significant risk factor for oncological outcomes. Regarding functional outcomes, the LL group showed a significant recovery in defecatory function 1 year postoperatively compared with the HL group. Conclusion LL with LNs dissection around the root of the IMA might not affect the oncologic outcomes comparing to HL; however, it has minimal benefit for defecatory function.