Clinical Significance of Non-Mass-Like Enhancement of Preoperative Magnetic Resonance Imaging in Breast Cancer Considering Breast-Conserving Surgery

PURPOSE: The purpose of this study was to investigate the significance of non-mass enhancement (NME) findings on preoperative breast magnetic resonance imaging (MRI) when invasive breast cancer patients with single lesions underwent breast-conserving surgery (BCS). METHODS: We reviewed the preoperative MRI findings of 252 patients who underwent BCS from January 2014 to September 2016. Based on the MRI findings, we divided the patients into two groups, those who did and did not have NME, and we retrospectively analyzed the clinical outcomes of the two groups. RESULTS: The NME group had 57 patients, and the no-NME group had 195 patients. The incidence of in situ lesions was higher in the NME group than in the no-NME group (p<0.001). Additionally, the positive resection margin rate on frozen biopsy was higher in the NME group than in the no-NME group (p=0.002). CONCLUSION: When preoperative MRI had NME findings, in situ lesions were more likely to accompany invasive breast cancer lesions, and the positive resection margin rate for frozen biopsy during BCS was high. Therefore, in these cases, the lesion should be excised more widely when BCS is performed, or frozen biopsy for resection margin during BCS should be performed if possible.

Selective B-RAF V600E Inhibitor PLX4032 Inhibits the Growth of Breast Cancer Cell Lines through Cell Cycle Arrest

PURPOSE: Breast cancer is the most common invasive cancer and the second common cause of death among women worldwide. Many researchers have focused on the effective treatment of advanced breast cancer using new drugs. Herein, we analyzed whether PLX4032, a B-RAF V600E inhibitor, could be used as a novel treatment for advanced breast cancer. METHODS: Two breast cancer cell lines, MCF7 and MDA-MB-231, were treated with the selective B-Raf inhibitor PLX4032 under adherent culture conditions and the effects of PLX4032 on cell growth, cell cycle duration, apoptosis and cell cycle related genes expression were evaluated. RESULTS: We found that PLX4032 dose-dependently inhibited cell growth in both cell lines through cell cycle arrest at phase G0/G1. However, PLX4032 treatment did not have a significant effect on cell apoptosis. In addition, CCNA2 gene expression was significantly decreased in the MCF7 cells in a dose-dependent manner. CONCLUSION: Our data demonstrated that treatment of breast cancer with PLX4032 could inhibit proliferation through cell cycle arrest. Therefore, PLX4032 might be a novel anticancer drug that can be used in the treatment of advanced breast cancer.

Time-Dependent Effects of Prognostic Factors in Advanced Gastric Cancer Patients

PURPOSE: This study aimed to identify time-dependent prognostic factors and demonstrate the time-dependent effects of important prognostic factors in patients with advanced gastric cancer (AGC). MATERIALS AND METHODS: We retrospectively evaluated 3,653 patients with AGC who underwent curative standard gastrectomy between 1991 and 2005 at the Korea Cancer Center Hospital. Multivariate survival analysis with Cox proportional hazards regression was used in the analysis. A non-proportionality test based on the Schoenfeld residuals (also known as partial residuals) was performed, and scaled Schoenfeld residuals were plotted over time for each covariate. RESULTS: The multivariate analysis revealed that sex, depth of invasion, metastatic lymph node (LN) ratio, tumor size, and chemotherapy were time-dependent covariates violating the proportional hazards assumption. The prognostic effects (i.e., log of hazard ratio [LHR]) of the time-dependent covariates changed over time during follow-up, and the effects generally diminished with low slope (e.g., depth of invasion and tumor size), with gentle slope (e.g., metastatic LN ratio), or with steep slope (e.g., chemotherapy). Meanwhile, the LHR functions of some covariates (e.g., sex) crossed the zero reference line from positive (i.e., bad prognosis) to negative (i.e., good prognosis). CONCLUSIONS: The time-dependent effects of the prognostic factors of AGC are clearly demonstrated in this study. We can suggest that time-dependent effects are not an uncommon phenomenon among prognostic factors of AGC.

Professional Identity of Elementary School Health Teachers: A Grounded Theory Approach

PURPOSE: This study was conducted to explore the professional identity of elementary school health teachers. METHODS: In-depth interviews with fifteen elementary school health teachers were conducted from July 2010 to August 2012. Qualitative data collected by the researcher including transcription and field notes were analyzed through an adapted methodology based on the Grounded Theory of Strauss and Corbin. RESULTS: Fifteen categories, 35 sub-categories and 120 concepts were obtained. The key category that was consistently maintained in identity formation was 'keeping themselves being a teacher providing nursing' which has three styles, 'focusing on health education', 'combining nursing and education' and 'focusing on providing nursing care'. CONCLUSION: Results of this study will provide basic information for preparing manuals regarding the range of activities in school health teachers' jobs, improving promotion and merit payment systems for school health teachers, creating support programs for them, and contributing to the formation and establishment of their professional identity.

Job Identity and Job Stress on Elementary School Health Teachers

PURPOSE: The purpose of this study was to contribute to enhancing elementary school health teachers professional job performance by analyzing their job identity and job stress. METHODS: The participants were 138 elementary school health teachers registered at the Busan Metropolitan City Office of Education, and the survey was conducted from the 22nd to 23rd of July, 2010. The collected data were analyzed by percentile, t-test, ANOVA, Pearson's correlation coefficient, and stepwise multiple regression using the SPSS/WIN 17.0 program. RESULTS: The average percentiles of job identity and job stress were 70.6 and 64.0 respectively. Among the sub-factors of job identity, autonomy was highest as 73.5, and among the sub-factors of job stress, job demand was highest as 73.9. There were significant differences in the degree of job identity and job stress according to education status, the number of classes, job satisfaction, enthusiasm for work, and the image of nursing teachers expressed in a word. The regression model explained 21.2% of the variance of job identity. job stress explained 32.0% of the variance. CONCLUSION: It is important to develop various comprehensive programs for improving job identity and managing job stress. In addition, it is necessary to provide support systems including persons, promotion and rewards to school health teachers.