Purpose: Adjuvant chemotherapy (AC) is recommended for muscle-invasive or lymph node-positive upper urinary tract urothelial carcinoma (UTUC) after radical nephroureterectomy (RNU). However, disease recurrences are frequently observed in pT1 disease, and AC may increase the risk of overtreatment in pT2 UTUC patients. This study aimed to validate a risk-adapted scoring model for selecting UTUC patients with ≤pT2 disease who would benefit from AC. Materials and Methods: We retrospectively analyzed 443 ≤pT2 UTUC patients who underwent RNU. A risk-adapted scoring model was applied, categorizing patients into low- or high-risk groups. Recurrence-free survival (RFS) and cancer-specific survival (CSS) were analyzed according to risk group. Results: Overall, 355 patients (80.1%) and 88 patients (19.9%) were categorized into the low- and high-risk groups, respectively, with the latter having higher pathological stages, concurrent carcinoma in situ, and synchronous bladder tumors. Disease recurrence occurred in 45 patients (10.2%), among whom 19 (5.4%) and 26 (29.5%) belonged to the low- and high-risk groups, respectively (p<0.001). High-risk patients had significantly shorter RFS (64.3% vs. 93.6% at 60 months; hazard ratio [HR] 13.66; p<0.001) and worse CSS (80.7% vs. 91.5% at 60 months; HR 4.25; p=0.002). Multivariate analysis confirmed that pT2 stage and the high-risk group were independent predictors of recurrence and cancer-specific death (p<0.001). Decision curve analysis for RFS showed larger net benefits with our model than with the T stage model. Conclusions The risk-adapted scoring model effectively predicts recurrence and identifies optimal candidates for AC post RNU in non-metastatic UTUC.

Colorectal cancer is the third most common cancer in Korea and the third leading cause of death from cancer. Treatment outcomes for colon cancer are steadily improving due to national health screening programs with advances in diagnostic methods, surgical techniques, and therapeutic agents.. The Korea Colon Cancer Multidisciplinary (KCCM) Committee intends to provide professionals who treat colon cancer with the most up-to-date, evidence-based practice guidelines to improve outcomes and help them make decisions that reflect their patients’ values and preferences. These guidelines have been established by consensus reached by the KCCM Guideline Committee based on a systematic literature review and evidence synthesis and by considering the national health insurance system in real clinical practice settings. Each recommendation is presented with a recommendation strength and level of evidence based on the consensus of the committee.

Background/Aims: Endoscopic papillectomy (EP) is increasingly used as an alternative to surgery for managing benign ampullary neoplasms. However, post-EP resection margins are often positive or indeterminate, and there is no consensus on the management of ampullary adenomas with positive or indeterminate margins after EP. This study was designed to compare the longterm outcomes between resected margin-negative (RMN) and resected margin-positive/indeterminate (RMPI) groups and to identify factors associated with clinical outcomes. Methods: This retrospective analysis included patients with ampullary adenoma without evidence of adenocarcinoma who underwent EP between 2004 and 2016. The RMN and RMPI groups were compared for recurrence rates and recurrence-free duration during a mean followup duration of 71.7±39.8 months. Factors related to clinical outcomes were identified using multivariate analysis. Results: Of the 129 patients who underwent EP, 82 were in the RMN group and 47 were in the RMPI group. The RMPI group exhibited a higher recurrence rate compared to the RMN group (14.6% vs 34.0%, p=0.019). However, the recurrence-free duration was not significantly different between the groups (34.7±32.6 months vs 36.2±27.4 months, p=0.900). Endoscopic treatment successfully managed recurrence in both groups (75% vs 75%). Submucosal injection was a significant risk factor for residual lesions (hazard ratio, 4.11; p=0.009) and recurrence (hazard ratio, 2.57; p=0.021). Conclusions Although ampullary adenomas with positive or indeterminate margins after EP showed a higher rate of recurrence at long-term follow-up, endoscopic treatment was effective with favorable long-term outcomes. Submucosal injection prior to resection was associated with increased risk of recurrence and residual lesions.

Dysphagia often occurs in cancer patients. The primary causes of dysphagia in cancer patients include new local dissemination of cancer cells or metastatic brain lesions, which needs to be accurately differentiated. Dermatomyositis is often associated with cancer and may manifest before or after the cancer diagnosis. Although early diagnosis and immunotherapy can improve dermatomyositis, its identification may be delayed in cancer patients due to complex comorbidities. We report a case of a 33-year-old woman with metastatic breast cancer who presented with dysphagia. The primary consideration was metastatic lesions. However, subsequent diagnosis revealed dermatomyositis.Symptoms, including facial swelling, dysarthria, and dysphagia, emerged 26 months after the cancer diagnosis. No new metastatic lesion was identified through imaging studies. A videofluoroscopic study (VFSS) revealed velopharyngeal insufficiency, reduced pharyngeal contraction, and excessive pharyngeal residue with silent aspiration. After a combination of further clinical, laboratory, and muscle biopsy findings, dermatomyositis was identified as the actual cause of dysphagia. The patient was treated with immunosuppressive and rehabilitative swallowing therapies, which improved her symptoms. This case underscores the critical importance of accurately identifying and promptly treating dysphagia in cancer patients. It particularly emphasizes the need to recognize dermatomyositis as a potential differential diagnosis in cancer patients presenting with dysphagia.

Purpose: Few studies have reported the prevalence of inflammatory bowel disease unclassified (IBDU) among Korean pediatric IBD (PIBD) population. To address this gap, we used two tertiary centers and nationwide population-based healthcare administrative data to estimate the prevalence of Korean pediatric IBDU at the time of diagnosis. Methods: We identified 136 patients aged 2–17 years with newly diagnosed IBD (94 Crohn’s disease [CD] and 42 ulcerative colitis [UC]) from two tertiary centers in Korea between 2005 and 2017. We reclassified these 136 patients using the revised Porto criteria. To estimate the population-based prevalence, we analyzed Korean administrative healthcare data between 2005 and 2016, which revealed 3,650 IBD patients, including 2,538 CD and 1,112 UC. By extrapolating the reclassified results to a population-based dataset, we estimated the prevalence of PIBD subtypes. Results: Among the 94 CD, the original diagnosis remained unchanged in 93 (98.9%), while the diagnosis of one (1.1%) patient was changed to IBDU. Among the 42 UC, the original diagnosis remained unchanged in 13 (31.0%), while the diagnoses in 11 (26.2%), 17 (40.5%), and one (2.4%) patient changed to atypical UC, IBDU, and CD, respectively. The estimated prevalences of CD, UC, atypical UC, and IBDU in the Korean population were 69.5%, 9.4%, 8.0%, and 13.1%, respectively. Conclusion This study is the first in Korea to estimate the prevalence of pediatric IBDU.This prevalence (13.1%) aligns with findings from Western studies. Large-scale prospective multicenter studies on PIBDU are required to examine the clinical features and outcomes of this condition.

Purpose: Since accurate lung cancer segmentation is required to determine the functional volume of a tumor in [ 18 F]FDG PET/CT, we propose a two-stage U-Net architecture to enhance the performance of lung cancer segmentation using [ 18 F]FDG PET/CT. Methods: The whole-body [ 18 F]FDG PET/CT scan data of 887 patients with lung cancer were retrospectively used for network training and evaluation. The ground-truth tumor volume of interest was drawn using the LifeX software. The dataset was randomly partitioned into training, validation, and test sets. Among the 887 PET/CT and VOI datasets, 730 were used to train the proposed models, 81 were used as the validation set, and the remaining 76 were used to evaluate the model. In Stage 1, the global U-net receives 3D PET/CT volume as input and extracts the preliminary tumor area, generating a 3D binary volume as output. In Stage 2, the regional U-net receives eight consecutive PET/CT slices around the slice selected by the Global U-net in Stage 1 and generates a 2D binary image as the output. Results: The proposed two-stage U-Net architecture outperformed the conventional one-stage 3D U-Net in primary lung cancer segmentation. The two-stage U-Net model successfully predicted the detailed margin of the tumors, which was determined by manually drawing spherical VOIs and applying an adaptive threshold. Quantitative analysis using the Dice similarity coefficient confirmed the advantages of the two-stage U-Net. Conclusion The proposed method will be useful for reducing the time and effort required for accurate lung cancer segmentation in [ 18 F]FDG PET/CT.

Purpose: Although previous research showed the importance of safety culture on health care workers' speaking up behaviors, it is not clear how particular safety culture domains are associated with the speaking up behaviors of hospital staff. Also, researchers have suggested that health care workers’ speaking up behaviors vary by profession, but there has been limited research into such differences. Thus, this study examined differences in perceptions of patient safety culture and the promotive and prohibitive speaking up behaviors of health care workers by profession and investigated the relationships between patient safety culture and the two types of speaking up behaviors. Methods: A descriptive correlational study was conducted using secondary data collected through an online survey of health care workers at a private, nonprofit, tertiary-level teaching hospital in South Korea. The sample (N = 831) consisted of nurses (54.0%), physicians (13.0%), and other licensed and unlicensed hospital personnel (33.0%). Analyses of variance were conducted to examine differences in study variables by profession. Hierarchical regression analyses were conducted to evaluate the effects of the seven patient safety culture factors on promotive and prohibitive voice after controlling for tenure and profession. Results: Perceptions of safety culture and promotive voice behaviors were higher for physicians compared with nurses. Communication openness, reporting patient adverse events, and unit supervisors' and hospital managements’ support for patient safety were significant predictors of both types of voice behaviors. Conclusion Hospital administrators and unit managers should create a supportive environment where staff feel free to voice their concerns and suggestions. They should also pay attention to the varying perspectives held by different groups of hospital workers and their different voice behaviors. Knowing which dimensions of patient safety culture are most strongly related to health care workers’ voice behaviors can guide patient safety improvement activities in health care organizations.