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.

The Korean Association of Urogenital Tract Infection and Inflammation and the Korea Disease Control and Prevention Agency regularly update, revise, and develop new content for the Korean sexually transmitted infection (STI) guidelines. These professional bodies respond to changing epidemiological trends and evolving scientific evidence, and consider advances in laboratory diagnostics and research. The principal recommendations of the 2023 Korean STI guidelines in terms of viral infection follow: 1) If genital herpes recurs more than 4–6 times annually, suppressive therapy with acyclovir 400 mg orally 2 times/day or famciclovir 250 mg orally 2 times/day or valacyclovir 500 mg orally once a day (for patients with <10 episodes/year) or valacyclovir 1 g orally once daily (for patients with ≥10 episodes/year) is recommended to prevent recurrence; 2) molecular human papillomavirus (HPV) testing is not recommended as a routine test for STI status, nor for determination of HPV vaccination status; and 3) patients should inform their current sexual partners about anogenital warts because the types of HPV that cause such warts can be passed to partners. These guidelines will be updated every 5 years and will be revised when new knowledge on STIs becomes available and there is a reasonable need to improve the guidelines. Physicians and other healthcare providers can use the guidelines to assist in the prevention and treatment of STIs.

Background: Programmed death ligand 1 (PD-L1) expression cannot currently be predicted through radiological findings. This study aimed to develop a prediction model capable of differentiating between positive and negative PD-L1 expression through a radiomics-based investigation of computed tomography (CT) images in patients with urothelial carcinoma. Methods: Sixty-four patients with urothelial carcinoma who underwent immunohistochemical testing for PD-L1 were retrospectively reviewed. The number of patients in the positive and negative PD-L1 groups (PD-L1 expression >5%) was 14 and 50, respectively. CT images obtained 90 seconds after contrast medium administration were selected for radiomic extraction. For all tumors, 1,691 radiomic features were extracted from CT using a manually segmented three-dimensional volume of interest. Univariate and multivariate logistic regression analyses were performed to identify radiomic features that were significant predictors of PD-L1 expression. For the radiomics-based model, a receiver operating characteristic (ROC) analysis was performed. Results: Among 64 patients, 14 were included in the PD-L1 positive group. Logistic regression analysis found that the following radiomic features significantly predicted PD-L1 expression: wavelet-low-pass, low-pass, and high-pass filters (LLH)_gray-level size-zone matrix (GLSZM)_SmallAreaEmphasis, wavelet-LLH_firstorder_Energy, log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis, original_shape_Maximum2DDiameterColumn, wavelet-low-pass, low-pass, and low-pass filters (LLL)_gray-level run-length matrix (GLRLM)_ShortRunEmphasis, and exponential_firstorder_Kurtosis. The radiomics signature was –4.0934+21.6224 (wavelet-LLH_GLSZM_SmallAreaEmphasis)+0.0044 (wavelet-LLH_firstorder_Energy)–4.7389 (log-sigma-0-5-mm-3D_GLSZM_SmallAreaHighGrayLevelEmphasis)+0.0573 (original_shape_Maximum2DDiameterColumn)–29.5892 (wavelet-LLL_GLRLM_ShortRunEmphasis)–0.4324 (exponential_firstorder_Kurtosis). The area under the ROC curve model representing the radiomics signature for differentiating cases that were deemed PD-L1 positive based on immunohistochemistry was 0.96. Conclusions This preliminary radiomics model derived from contrast-enhanced CT predicted PD-L1 positivity in patients with urothelial cancer.

Background/Aims: Although endoscopic ultrasound (EUS)-guided fine needle aspiration (FNA) and fine needle biopsy (FNB) are widely used for tissue acquisition of pancreatic solid mass, the optimal strategy of this procedure has not been established yet. The aim of this nationwide study was to investigate the current practice patterns of EUS-FNA/FNB for pancreatic solid mass in Korea. Methods: The Policy-Quality Management of the Korean Pancreatobiliary Association (KPBA) developed a questionnaire containing 22 questions. An electronic survey consisting of the questionnaire was distributed by e-mail to members registered to the KPBA. Results: A total of 101 respondents completed the survey. Eighty respondents (79.2%) performed preoperative EUS-FNA/FNB for operable pancreatic solid mass. Acquire needles (60.4%) were used the most, followed by ProCore needles (47.5%). In terms of need size, most respondents (>80%) preferred 22-gauge needles regardless of the location of the mass. Negative suction with a 10-mL syringe (71.3%) as sampling technique was followed by stylet slow-pull (41.6%). More than three needle passes for EUS-FNA/FNB was performed by most respondents (>80%). The frequency of requiring repeated procedure was significantly higher in respondents with a low individual volume (<5 per month, p=0.001). Prophylactic antibiotics were routinely used in 39 respondents (38.6%); rapid on-site pathologic evaluation was used in 6.1%. Conclusions According to this survey, practices of EUS-FNA/FNB for pancreatic solid mass varied substantially, some of which differed considerably from the recommendations present in existing guidelines. These results suggest that the development of evidence-based quality guidelines fitting Korean clinical practice is needed to establish the optimal strategy for this procedure.

Purpose: Outcome analysis of urachal cancer (UraC) is limited due to the scarcity of cases and different staging methods compared to urothelial bladder cancer (UroBC). We attempted to assess survival outcomes of UraC and compare to UroBC after stage-matched analyses. Materials and Methods: Total 203 UraC patients from a multicenter database and 373 UroBC patients in single institution from 2000 to 2018 were enrolled (median follow-up, 32 months). Sheldon stage conversion to corresponding TNM staging for UraC was conducted for head-to-head comparison to UroBC. Perioperative clinical variables and pathological results were recorded. Stage-matched analyses for survival by stage were conducted. Results: UraC patients were younger (mean age, 54 vs. 67 years; p < 0.001), with 163 patients (80.3%) receiving partial cystectomy and 23 patients (11.3%) radical cystectomy. UraC was more likely to harbor ≥ pT3a tumors (78.8% vs. 41.8%). While 5-year recurrence-free survival, cancer-specific survival (CSS) and overall survival were comparable between two groups (63.4%, 67%, and 62.1% in UraC and 61.5%, 75.9%, and 67.8% in UroBC, respectively), generally favorable prognosis for UraC in lower stages (pT1-2) but unfavorable outcomes in higher stages (pT4) compared to UroBC was observed, although only 5-year CSS in ≥ pT4 showed statistical significance (p=0.028). Body mass index (hazard ratio [HR], 0.929), diabetes mellitus (HR, 1.921), pathologic T category (HR, 3.846), and lymphovascular invasion (HR, 1.993) were predictors of CSS for all patients. Conclusion Despite differing histology, UraC has comparable prognosis to UroBC with relatively favorable outcome in low stages but worse prognosis in higher stages. The presented system may be useful for future grading and risk stratification of UraC.

Objective: The aim of this study was 1) to investigate the prevalence and pattern of dental anomalies (DAs), 2) to compare DAs according to the type of malocclusion, and 3) to investigate the correlation between tooth impaction and other DAs in the Korean orthodontic population. Methods: A total of 3,240 orthodontic patients were classified as Class I, Class II, or Class III malocclusion groups. The presence and location of common DAs, including impaction, microdontia, agenesis, supernumerary tooth, transposition, and fusion, were identified by examining diagnostic records. Furthermore, samples were classified as Group 1 without impaction or Group 2 with impaction. The prevalence of other DAs concurrent with impaction was investigated and compared to Group 1. Results: Impaction was the most prevalent DA, followed by microdontia, agenesis, and supernumerary. Class I and Class III groups showed the same order of prevalence, but agenesis was more frequent than microdontia in the Class II group. The prevalence of the four DAs was lowest in the Class III group. Overall, 8.6% of patients were classified into Group 2. The incidence of DAs other than impaction and the prevalence of multiple concurrent DAs were significantly higher in Group 2. Impaction showed a significant relationship with supernumerary tooth, transposition, and fusion. Conclusions The prevalence and pattern of DAs varied depending on the type of malocclusion. As there was a higher risk of other DAs in patients with impacted teeth, early detection of the impacted tooth and a detailed diagnosis of other possible DAs may be essential.

Purpose: There is a potential risk that lobular carcinoma in situ (LCIS) on preoperative biopsy might be diagnosed as ductal carcinoma in situ (DCIS) or invasive carcinoma in the final pathology. This study aimed to evaluate the rate of upgrade of LCIS on preoperative biopsy to DCIS or invasive carcinoma. Materials and Methods: Data of 55 patients with LCIS on preoperative biopsy were analyzed. All patients underwent surgery between 1991 and 2016 at Severance Hospital in Seoul, Korea. We analyzed the rate of upgrade of preoperative LCIS to DCIS or invasive cancer in the final pathology. The clinicopathologic features related to the upgrade were evaluated. Results: The rate of upgrade of LCIS to DCIS or invasive carcinoma was 16.4% (9/55). In multivariate analysis, microcalcification and progesterone receptor expression were significantly associated with the upgrade of LCIS (p=0.023 and p=0.044, respectively). Conclusion The current study showed a relatively high rate of upgrade of LCIS on preoperative biopsy to DCIS or invasive cancer. The presence of microcalcification and progesterone receptor expression may be potential predictors of upgradation of LCIS on preoperative biopsy. Surgical excision of the LCIS during preoperative biopsy could be a management option to identify the concealed malignancy.

Purpose: Epidermal growth factor receptor kinase domain duplication (EGFR-KDD) is a rare and poorly understood oncogenic mutation in non–small cell lung cancer (NSCLC). We aimed to investigate the acquired resistance mechanism of EGFR-KDD against EGFR-TKIs. Materials and Methods: We identified EGFR-KDD in tumor tissue obtained from a patient with stage IV lung adenocarcinoma and established the patient-derived cell line SNU-4784. We also established several EGFR-KDD Ba/F3 cell lines: EGFR-KDD wild type (EGFR-KDDWT), EGFR-KDD domain 1 T790M (EGFR-KDDD1T), EGFR-KDD domain 2 T790M (EGFR-KDDD2T), and EGFR-KDD both domain T790M (EGFR-KDDBDT). We treated the cells with EGFR tyrosine kinase inhibitors (TKIs) and performed cell viability assays, immunoblot assays, and ENU (N-ethyl-N-nitrosourea) mutagenesis screening. Results: In cell viability assays, SNU-4784 cells and EGFR-KDDWT Ba/F3 cells were sensitive to 2nd generation and 3rd generation EGFR TKIs. In contrast, the T790M-positive EGFR-KDD Ba/F3 cell lines (EGFR-KDDT790M) were only sensitive to 3rd generation EGFR TKIs. In ENU mutagenesis screening, we identified the C797S mutation in kinase domain 2 of EGFR-KDDBDT Ba/F3 cells. Based on this finding, we established an EGFR-KDD domain 1 T790M/domain 2 cis-T790M+C797S (EGFR-KDDT/T+C) Ba/F3 model, which was resistant to EGFR TKIs and anti-EGFR monoclonal antibody combined with EGFR TKIs. Conclusion Our study reveals that the T790M mutation in EGFR-KDD confers resistance to 1st and 2nd generation EGFR TKIs, but is sensitive to 3rd generation EGFR TKIs. In addition, we identified that the C797S mutation in kinase domain 2 of EGFR-KDDT790M mediates a resistance mechanism against 3rd generation EGFR TKIs.

Purpose: The aims of this study were to investigate the clinical value of Rab27a as a urinary biomarker, and its efficiency in the prediction of bladder cancer grade. Materials and Methods: The expression of Rab27a in urine samples of patients with bladder cancer, cell line (T-24), and tissue samples of patients with bladder cancer was estimated via quantitative reverse transcription polymerase chain reaction (qRT-PCR). The Rab27a expression level was investigated according to sex, age, and histological grade via qRT-PCR and Western blotting. Results: Rab27a was also expressed at high levels in urine compared to cell lines and tissues from bladder cancer patients. In addition, Rab27a expression varied significantly according to tumor grade (p<0.001). Rab27a was expressed at high levels in male and elderly patients, however, there was not statistically significant. Conclusions Our results indicated that Rab27a is valuable as a urinary diagnostic biomarker for bladder cancer. In addition, it may serve as a predictive factor for determining bladder cancer grade.

Purpose: To investigate the correlation between preoperative De Ritis ratio (aspartate transaminase [AST]/alanine transaminase [ALT]) and postoperative clinical outcome in patients with upper urinary tract carcinoma (UTUC) who underwent radical nephroureterectomy (RNU) and adjuvant chemotherapy (ACH). Materials and Methods: We respectively analyzed the clinical and pathological data of 102 patients who underwent RNU and ACH for UTUC. Patients were divided into 2 groups, according to the optimal value of AST/ALT ratio. The effect of the AST/ALT ratio was analyzed by the Kaplan-Meier method and Cox regression hazard models for patients’ cancer-specific survival (CSS) and overall survival (OS). Results: Mean survival time was 50.5±41.2 months. Mean age was 61.4±9.7years. Forty-one of the patients (46.5%) were in the high AST/ALT group. According to receiver operating characteristic analysis, the optimal AST/ALT ratio was 1.2. In Kaplan-Meier analyses, the high AST/ALT group showed worse outcomes in OS (p=0.007) and CSS (p=0.011). Using Cox regression models of clinical and pathological parameters to predict OS, high AST/ALT ratio (hazard ratio [HR], 5.428; 95% confidence interval [CI]; 1.803–16.334; p=0.002), pathological T3 (pT3) or higher (HR, 1.464; 95% CI; 1.156-1.857; p=0.002), and to predict CSS, high AST/ALT ratio (HR, 4.417; 95% CI; 1.545–12.632; p=0.005), and pT3 or higher (HR, 1.475; 95% CI; 1.172–1.904; p=0.002) were determined as independent prognostic factors. Conclusions Pretreatment AST/ALT ratio is a significant independent predictor of CSS and OS in advanced UTUC patients receiving systemic ACH after RNU.