Objective: Automated breast ultrasound (ABUS) is a relevant imaging technique for early breast cancer diagnosis and is increasingly being used as a supplementary tool for mammography. This study compared the performance of ABUS and handheld ultrasound (HHUS) in detecting and characterizing the axillary lymph nodes (LNs) in patients with breast cancer. Materials and Methods: We retrospectively reviewed the medical records of women with recently diagnosed early breast cancer (≤ T2) who underwent both ABUS and HHUS examinations for axilla (September 2017–May 2018). ABUS and HHUS findings were compared using pathological outcomes as reference standards. Diagnostic performance in predicting any axillary LN metastasis and heavy nodal-burden metastases (i.e., ≥ 3 LNs) was evaluated. The ABUS-HHUS agreement for visibility and US findings was calculated. Results: The study included 377 women (53.1 ± 11.1 years). Among 385 breast cancers in 377 patients, 101 had axillary LN metastases and 30 had heavy nodal burden metastases. ABUS identified benign-looking or suspicious axillary LNs (average, 1.4 ± 0.8) in 246 axillae (63.9%, 246/385). According to the per-breast analysis, the sensitivity, specificity, positive and negative predictive values, and accuracy of ABUS in predicting axillary LN metastases were 43.6% (44/101), 95.1% (270/284), 75.9% (44/58), 82.6% (270/327), and 81.6% (314/385), respectively. The corresponding results for HHUS were 41.6% (42/101), 95.1% (270/284), 75.0% (42/56), 82.1% (270/329), and 81.0% (312/385), respectively, which were not significantly different from those of ABUS (P ≥ 0.53). The performance results for heavy nodal-burden metastases were 70.0% (21/30), 89.6% (318/355), 36.2% (21/58), 97.3% (318/327), and 88.1% (339/385), respectively, for ABUS and 66.7% (20/30), 89.9% (319/355), 35.7% (20/56), 97.0% (319/329), and 88.1% (339/385), respectively, for HHUS, also not showing significant difference (P ≥ 0.57). The ABUS–HHUS agreement was 95.9% (236/246; Cohen’s kappa = 0.883). Conclusion Although ABUS showed limited sensitivity in diagnosing axillary LN metastasis in early breast cancer, it was still useful as the performance was comparable to that of HHUS.

Purpose: Several predictive models have been developed to predict the pathological complete response (pCR) after neoadjuvant chemotherapy (NAC); however, few are broadly applicable owing to radiologic complexity and institution-specific clinical variables, and none have been externally validated. This study aimed to develop and externally validate a machine learning model that predicts pCR after NAC in patients with breast cancer using routinely collected clinical and demographic variables. Methods: The electronic medical records of patients with advanced breast cancer who underwent NAC before surgical resection between January 2017 and December 2020 were reviewed. Patient data from Seoul National University Bundang Hospital were divided into training and internal validation cohorts. Five machine learning techniques, including gradient boosting machine (GBM), support vector machine, random forest, decision tree, and neural network, were used to build predictive models, and the area under the receiver operating characteristic curve (AUC) was compared to select the best model. Finally, the model was validated using an independent cohort from Seoul National University Hospital. Results: A total of 1,003 patients were included in the study: 287, 71, and 645 in the training, internal validation, and external validation cohorts, respectively. Overall, 36.3% of the patients achieved pCR. Among the five machine learning models, the GBM showed the highest AUC for pCR prediction (AUC, 0.903; 95% confidence interval [CI], 0.833–0.972).External validation confirmed an AUC of 0.833 (95% CI, 0.800–0.865). Conclusion Commonly available clinical and demographic variables were used to develop a machine learning model for predicting pCR following NAC. External validation of the model demonstrated good discrimination power, indicating that routinely collected variables were sufficient to build a good prediction model.

Purpose: Acute promyelocytic leukemia (APL) is a rare disease in children and there are some different characteristics between children and adult. We aimed to evaluate incidence, clinical characteristics and treatment outcomes of pediatric APL in Korea. Materials and Methods: Seventy-nine pediatric APL patients diagnosed from January 2009 to December 2016 in 16 tertiary medical centers in Korea were reviewed retrospectively. Results: Of 801 acute myeloid leukemia children, 79 (9.9%) were diagnosed with APL. The median age at diagnosis was 10.6 years (range, 1.3 to 18.0). Male and female ratio was 1:0.93. Thirty patients (38.0%) had white blood cell (WBC) count greater than 10×109/L at diagnosis. All patients received induction therapy consisting of all-trans retinoic acid and chemotherapy. Five patients (6.6%) died during induction chemotherapy and 66 patients (86.8%) achieved complete remission (CR) after induction chemotherapy. The causes of death were three intracranial hemorrhage, one cerebral infarction, and one sepsis. Five patients (7.1%) suffered a relapse during or after maintenance chemotherapy. The estimated 4-year event-free survival and overall survival (OS) rates were 82.1%±4.4%, 89.7%±5.1%, respectively. The 4-year OS was significantly higher in patients with initial WBC < 10×109/L than in those with initial WBC ≥ 10×109/L (p=0.020). Conclusion This study showed that the CR rates and survival outcomes in Korean pediatric APL patients were relatively good. The initial WBC count was the most important prognostic factor and most causes of death were related to serious bleeding in the early stage of treatment.

Objective: The optimal imaging approach for evaluating pathological nipple discharge remains unclear. We investigated the value of adding ductography to ultrasound (US) for evaluating pathologic nipple discharge in patients with negative mammography findings. Materials and Methods: From July 2003 to December 2018, 101 women (mean age, 46.3 ± 12.2 years; range, 23–75 years) with pathologic nipple discharge were evaluated using pre-ductography (initial) US, ductography, and post-ductography US. The imaging findings were reviewed retrospectively. The standard reference was surgery (70 patients) or > 2 years of followup with US (31 patients). The diagnostic performances of initial US, ductography, and post-ductography US for detecting malignancy were compared using the McNemar’s test or a generalized estimating equation. Results: In total, 47 papillomas, 30 other benign lesions, seven high-risk lesions, and 17 malignant lesions were identified as underlying causes of pathologic nipple discharge. Only eight of the 17 malignancies were detected on the initial US, while the remaining nine malignancies were detected by ductography. Among the nine malignancies detected by ductography, eight were detected on post-ductography US and could be localized for US-guided intervention. The sensitivities of ductography (94.1% [16/17]) and post-ductography US (94.1% [16/17]) were significantly higher than those of initial US (47.1% [8/17]; p = 0.027 and 0.013, respectively). The negative predictive value of post-ductography US (96.9% [31/32]) was significantly higher than that of the initial US (83.3% [45/54]; p = 0.006). Specificity was significantly higher for initial US than for ductography and post-ductography US (p = 0.001 for all). Conclusion The combined use of ductography and US has a high sensitivity for detecting malignancy in patients with pathologic nipple discharge and negative mammography. Ductography findings enable lesion localization on second-look post-ductography US, thus facilitating the selection of optimal treatment plans.

Purpose: Estrogen receptor (ER) expression in breast cancer plays an essential role in carcinogenesis and disease progression. Recently, tumors with low level (1%-10%) of ER expression have been separately defined as ER low positive (ERlow). It is suggested that ERlow tumors might be morphologically and behaviorally different from tumors with high ER expression (ERhigh). Materials and Methods: Retrospective analysis of a prospective cohort database was performed. Patients who underwent curative surgery for early breast cancer and had available medical records were included for analysis. Difference in clinicopathological characteristics, endocrine responsiveness and five-year recurrence-free survival was evaluated between different ER subgroups (ERhigh, ERlow, and ER-negative [ER–]). Results: A total of 2,162 breast cancer patients were included in the analysis, Tis and T1 stage. Among them, 1,654 (76.5%) were ERhigh, 54 (2.5%) were ERlow, and 454 (21.0%) were ER- patients. ERlow cases were associated with smaller size, higher histologic grade, positive human epidermal growth factor receptor 2, negative progesterone receptor, and higher Ki-67 expression. Recurrence rate was highest in ER– tumors and was inversely proportional to ER expression. Recurrence-free survival was not affected by hormonal therapy in the ERlow group (p=0.418). Conclusion ERlow breast cancer showed distinct clinicopathological features. ERlow tumors seemed to have higher recurrence rates compared to ERhigh tumors, and they showed no significant benefit from hormonal therapy. Future large scale prospective studies are necessary to validate the treatment options for ERlow breast cancer.

Purpose: This study aimed to predict a heavy nodal burden (≥3 metastatic axillary lymph nodes [LNs]) using axillary ultrasonography (US) and US-guided fine-needle aspiration biopsy (FNAB) in patients with early-stage breast cancer. Methods: We retrospectively reviewed the medical records of 403 women (404 cancers) who underwent US-guided FNAB for axillary LN staging from January 2006 to December 2015. US findings and US-guided FNAB results were reviewed and compared using pathology results as the reference. Diagnostic performance was analyzed, and clinicopathological and radiological findings were compared between patients with <3 metastatic LNs and ≥3 metastatic LNs. Results: The final pathology results revealed that 20.5% of cancers had heavy nodal metastases. US-guided FNAB showed significantly higher sensitivity (79.0% vs. 63.0%, P=0.009) and specificity (84.8% vs. 79.3%, P=0.036) in predicting heavy nodal metastases than did US. The presence of a larger number of suspicious LNs (two or more) on axillary US and positive FNAB results were significantly correlated with a heavy nodal burden in the multivariate analysis. The odds ratios were 4.20 (95% confidence interval [CI], 1.90 to 9.39) for two suspicious LNs, 9.40 (95% CI, 2.99 to 29.54) for three or more suspicious LNs, and 14.22 (95% CI, 6.78 to 29.82) for positive FNAB results. Conclusion The number of suspicious LNs detected on axillary US and FNAB results can help predict a heavy axillary nodal burden in patients with early-stage breast cancer.

The Committee of Clinical Practice Guidelines of the Korean Diabetes Association revised and updated the 6th Clinical Practice Guidelines in 2019. Targets of glycemic, blood pressure, and lipid control in type 2 diabetes mellitus (T2DM) were updated. The obese and overweight population is increasing steadily in Korea, and half of the Koreans with diabetes are obese. Evidence-based recommendations for weight-loss therapy for obesity management as treatment for hyperglycemia in T2DM were provided. In addition, evidence from large clinical studies assessing cardiovascular outcomes following the use of sodium-glucose cotransporter-2 inhibitors and glucagon-like peptide 1 receptor agonists in patients with T2DM were incorporated into the recommendations.
Blood Pressure ; Diabetes Mellitus, Type 2 ; Diagnosis ; Glucagon-Like Peptide 1 ; Humans ; Hyperglycemia ; Korea ; Obesity ; Overweight

PURPOSE: Although the DTaP and Tdap vaccines used to prevent pertussis have been used for a long time, there is no standard method for measuring pertussis antigens. Therefore, this preliminary study was conducted to develop an enzyme-linked immunosorbent assay method using an animal model for measuring antibodies against pertussis toxin, the most important pertussis pathogenic antigen, in the sera of vaccinated mice. MATERIALS AND METHODS: Bordetella pertussis Tohama phase I was cultured for 24–30 hours, and then pertussis toxin was purified from the culture medium by chromatography. Purified pertussis toxin was diluted in phosphate-buffered saline-coating buffer, and 100 µL of diluted pertussis toxin was added to each well and reacted at room temperature for 4 hours. Positive serum was diluted to 1/1,250–1/80,000 and negative serum was diluted to 1/50 to determine the coating concentration with the optimal signal/noise ratio. Optimal test conditions were confirmed from the dilution factors of the secondary antibody and streptavidin horseradish peroxidase (SA-HRP). RESULTS: Optimal conditions were as follows: 4 µg/mL for coating antigen; 1/40,000 for secondary antibody; and 1/1,000 for the SA-HRP dilution factor. Comparison of the sera obtained from mice treated with a developing vaccine and commercial vaccine with National Institute for Biological Standard and Control standard serum under the established conditions showed the following results: 1,300.62, 534.94, and 34.85, respectively. CONCLUSION: The method developed in this study is suitable for measuring anti-pertussis toxin antibodies and may be applicable for clinical sample analysis or indirect diagnosis of pertussis.
Animals ; Antibodies ; Bordetella pertussis ; Chromatography ; Diagnosis ; Enzyme-Linked Immunosorbent Assay* ; Horseradish Peroxidase ; Methods ; Mice* ; Models, Animal ; Pertussis Toxin ; Streptavidin ; Vaccines ; Whooping Cough

BACKGROUND/AIMS: Recent Korean studies performed over the past few decades have shown diminishing efficacy and unacceptability of clarithromycin-based triple therapy as first-line eradication therapy for Helicobacter pylori infection, based on evidence of a declining eradication rate. Triple therapy continues to be used as first-line eradication therapy despite concerns regarding high clarithromycin resistance among Koreans. Patient compliance and acid suppression are important factors associated with the H. pylori eradication rate. We investigated whether regular administration of a proton pump inhibitor (PPI) 30 minutes before a meal can improve the eradication rate. MATERIALS AND METHODS: We retrospectively analyzed the data of 316 patients who were treated with first-line triple therapy (PPI, amoxicillin, and clarithromycin) for H. pylori infection between January 2012 and September 2017. Patients were divided into 2 groups based on the time of administration of the PPI (group A: before a meal, group B: after a meal). The urea breath test was performed 4~6 weeks after eradication of infection. RESULTS: Notably, 249 patients (78.8%, 249/316) showed successful eradication. The eradication rates in groups A and B were 87.5% (49/56 patients) and 76.9% (200/260 patients), respectively. We observed that regular administration of PPI before meals improved the eradication rate (P=0.079). CONCLUSIONS: We observed that although clarithromycin-based triple therapy was associated with an overall eradication rate <80%, regular PPI administration before meals improved the eradication rate. Regular PPI administration before meals and effective education to improve patient compliance could improve the eradication rate through maximal acid suppression.
Amoxicillin ; Breath Tests ; Clarithromycin ; Education ; Helicobacter pylori ; Helicobacter ; Humans ; Meals ; Patient Compliance ; Proton Pump Inhibitors ; Proton Pumps ; Protons ; Retrospective Studies ; Urea

PURPOSE: The management of benign intraductal papilloma (IDP) without atypia diagnosed on core needle biopsy (CNB) remains controversial. This study was performed to evaluate the rate of upgrading to malignancy or high-risk lesions after excision and to identify factors associated with upgrading using a large series of benign IDP cases without atypia. METHODS: We included patients who were diagnosed as having benign IDP without atypia on CNB and underwent surgical or vacuum-assisted excision between 2010 and 2015. We analyzed the clinical, radiologic, and histopathologic features of IDPs that were upgraded to malignancy or high-risk lesions after excision. RESULTS: A total of 511 benign IDPs without atypia diagnosed via CNB were identified, of which 398 cases were treated with excision. After reviewing these cases, four cases of high-risk lesions in adjacent tissue on CNB, two cases which were revealed as papilloma with atypia, and nine cases of malignancy in the same breast were excluded. In the remaining 383 cases, the rate of upgrading to malignancy and high-risk lesions after excision was 0.8% and 4.4%, respectively. The presence of concurrent contralateral breast cancer, the presence of symptoms, and multifocality were factors significantly associated with upgrading to malignancy on subsequent excision. Surgical excision rather than vacuum-assisted excision was significantly associated with upgrading to high-risk lesions or malignancy. CONCLUSION: The rate of upgrading to malignancy for benign IDP without atypia was very low, suggesting that close clinical and radiologic observation may be sufficient for patients with benign IDP without atypia on CNB under proper settings.
Biopsy, Large-Core Needle* ; Breast ; Breast Neoplasms ; Humans ; Papilloma ; Papilloma, Intraductal*