Evaluation of frozen-section analysis of surgical margins in the treatment of breast cancer.

OBJECTIVE: To evaluate surgical margins in cases of ductal carcinoma through a histopathological exam using frozen sections. MATERIALS AND METHODS: Retrospective study encompassing 242 conservative surgeries, 179 of which included intraoperative frozen-section histopathology and 63 intraoperative nonfreezing techniques (macroscopy/gross examination and cytology). The results of such analyses were compared with those of the histology processing following paraffin embedment and hematoxylin and eosin (H & E) staining. A margin was deemed free when the distance between the tumor and the surgical border was equal to or greater than two millimeters. The factors given consideration for possibly affecting the results were: age, surgical aspects (skin removal and widening of surgical margins), histopathological findings (size, affected lymph nodes, and angiolymphatic invasion), and extensive intraductal and immunohistochemical components (estrogen, progesterone, Ki-67, and HER-2 receptors). In the statistical analyses, the chi-square test was used and negative predictive values were calculated. RESULTS: The negative predictive values were 87.1% and 79.3% for frozen and nonfrozen sections, respectively. There was no significant difference between the two groups (p = 0.14). The factors under consideration had no influence on the results of the intraoperative exam of the margins. CONCLUSION: The present study allowed to conclude that the intraoperative exam of the surgical margins by frozen section is not superior to a macroscopy and/or cytology exam.

Heart rate variability analysis to investigate autonomic nervous system activity among the three premature ventricular complex circadian types: An observational study

Background and Objective@#Premature ventricular complex (PVC) burden exhibits one of three circadian types, classified as fast-type, slow-type, and independent-type PVC. It is unknown whether PVC circadian types have different heart rate variability (HRV) parameter values. Therefore, this study aimed to evaluate differences in HRV circadian rhythm among fast-, slow-, and independent-type PVC. @*Methods@#This cross-sectional observational study consecutively recruited 65 idiopathic PVC subjects (23 fast-, 20 slow-, and 22 independent-type) as well as five control subjects. Each subject underwent a 24-hour Holter to examine PVC burden and HRV. HRV analysis included components that primarily reflect global, parasympathetic, and sympathetic activities. Repeated measures analysis of variance was used to compare differences in HRV circadian rhythm by PVC type. Results. The average PVC burden was 15.7%, 8.4%, and 13.6% in fast-, slow-, and independent-type idiopathic PVC subjects, respectively. Global, parasympathetic nervous system, and sympathetic nervous system HRV parameters were significantly lower in independenttype PVC versus fast- and slow-type PVC throughout the day and night. Furthermore, we unexpectedly found that tendency towards sympathetic activity dominance during nighttime was only in independent-type PVC.@*Conclusion@#The HRV parameters are reduced in patients with independent-type PVC compared to fast- and slowtype PVC. Future research is warranted to determine possible differences in the prognosis between the three PVC types.