Measuring cfDNA integrity as a biomarker for predicting neoadjuvant chemotherapy response in breast cancer patients: a pilot study.

PURPOSE: Circulating cell-free DNA (cfDNA) is a promising biomarker for predicting treatment response and disease outcomes in Breast Cancer (BC) patients undergoing neoadjuvant chemotherapy (NAC). To determine if cfDNA originates from tumors, matching tumor and cfDNA gene mutations are necessary, often requiring tumor DNA sequencing. We assessed plasma cfDNA integrity by measuring concentrations and ratios of larger-to-smaller Alu DNA fractions as a potential biomarker, eliminating the need for prior tumor sequencing. METHODS: We included patients with localized and/or locally advanced BC receiving standard NAC alone or in combination with immunotherapy and/or anti-HER2 targeted therapy. Blood samples were collected before treatment, every 2 weeks during treatment, and before surgery. RESULTS: Of the 38 evaluated patients, only 28 completed the protocol and underwent surgery after NAC. Seven patients (25%) achieved a pathologic complete response (pCR). We found that cfDNA integrity (cfDNAI) levels at 15 days after starting NAC were significantly higher in patients who achieved pCR (p = 0.045) and correlated significantly with Disease-Free Survival (DFS) in univariate analysis (p = 0.0371). CONCLUSIONS: Evaluation of cfDNAI 2 weeks after NAC initiation appears to be an early biomarker for tumor pCR and DFS. Measuring Alu fragments of different lengths may replace techniques requiring prior tumor sequencing to measure ctDNA, reducing costs and complexity of cfDNA serial measurements in BC patients undergoing NAC.

Impact of the Vaccination Against COVID-19 on Frontline Health Workers.

INTRODUCTION: Brazil has been facing the pandemic of COVID-19 since march 2020. More than 540,000 people have died from this disease in the country. Some estimates indicate that the population exposed to SARS-CoV-2 represents 1 to 20%. However, these data are questionable due to the number of asymptomatic and untested individuals. As a result, vaccination for COVID- 19 has become the main means of achieving herd immunity. OBJECTIVES: To demonstrate, through local sampling, that broad and rapid vaccination may decrease the rate of COVID-19 detection in individuals potentially exposed to the SARS-CoV-2 virus. METHODS: A total of 1,128 individuals were studied, including students and health professionals from Centro Universitário FMABC, who received the two doses of the vaccine for COVID-19 (Oxford/Astrazeneca ® and CoronaVac®). RESULTS: In the studied period, there was a 41% reduction in the demand for RT-PCR tests after vaccination. And a 78.3% reduction in positive results after vaccination started. CONCLUSION: The results of this study showed that even vaccinating a population with higher exposure to the risk of contamination significantly reduced test positivity and the demand to perform these tests. This emphasizes that vaccination is the best strategy to achieve herd immunity and reduce the spread of the disease.

The Impact of Inflammatory Profile on Selenium Levels in Hemodialysis Patients.

INTRODUCTION: Hemodialysis stands out as an eligible treatment for patients with chronic kidney disease. The subsequent inflammatory process resulting from this disease and hemodialysis per se is exacerbated in this therapy. Selenium (Se) is an essential trace element that can participate in the inhibition of pro-oxidant and pro-inflammatory processes and could be considered a measurement that indicates the progression of chronic kidney disease and inflammation. OBJECTIVES: The present study investigated selenemia in hemodialysis patients of the ABC region of São Paulo and aimed to establish the correlation between an inflammatory marker and selenemia in this conditions disease. METHODS: This is an observational cross-sectional study of the Faculdade de Medicina do ABC in patients submitted to hemodialysis three times a week for at least six months. The eligible group composed of 21 patients, who filled out forms and underwent biochemical tests (colorimetric enzyme methods, flow cytometer, turbidimetric method and mass spectrometry). RESULTS: The study population showed, women (70%), men (30%) with a mean age of 47 ± 17 years, Caucasians (36%) and non-Caucasian (64%), hypertensive (68%), smokers (53%) and non-smokers (64%). There was a hegemonic prevalence of systolic arterial hypertension (SAH) 68.1% in relation to diabetes mellitus (DM) (50%). Pre and post hemodialysis (HD) selenemia showed statistical significance, which did not occur with Creactive protein. There was a predominance of females in our sample; the pre- and post- HD selenemia were within the normal range of the reference values; there was a statistically significant correlation between pre and post-HD selenemia; there was no correlation with statistical significance between values of pre and post-HD C-reactive protein. CONCLUSION: Our data showed that there was no direct relationship between pre- and post- HD inflammation and pre- and post-HD selenemia.