Analysis of Ki-67 expression in women with breast cancer: Comparative evaluation of two different methodologies by immunophenotyping.

The Ki-67 antigen is a nuclear protein with proven prognostic value in different neoplasms and recognizes the predictive value in breast cancer (BC). No consensus exists on the ideal cutoff point. In this study, Ki-67 expression was evaluated in samples of BC by flow cytometry (FC) and compared with immunohistochemical (IHC) examination. For this, the BC tissue samples were sectioned, macerated, filtered, and marked with anti-Ki-67 FITC and anti-CD45 V500 antibodies. We selected the neoplastic cells according to CD45 expression and size and internal complexity (FSC × SSC) using the Infinicity 1.7 software. Lymphocytes were negative control. We compared the results with IHC analyses carried out in parallel and independently. The expression of Ki-67 was evaluated in both methodologies through Bland-Altman analysis. Among the 44 samples analyzed, only three showed bias higher than the established confidence interval (mean bias 2.1%, p = 0.62), with no significant difference for the perfect mean bias (0%). Therefore, one can state that FC provides results equivalent to IHC analysis and possibly analyzes more cells simultaneously. The results obtained in this study show the absence of observational bias through software analysis in a larger number of tumor cell populations. We can conclude that FC may be a promising alternative method for investigating Ki-67 in solid tumours.

Analysis of the presence of FLT3 gene mutation and association with prognostic factors in adult and pediatric acute leukemia patients

ABSTRACT When the FLT3 gene is mutated, it originates a modified receptor with structural changes, which give survival advantage and malignant hematopoietic cell proliferation. Thus, the presence of mutations in this gene is considered an unfavorable prognostic factor. A total of 85 consecutive samples of newly diagnosed untreated patients with AL were included in the study after they provided their informed consent. FLT3 gene mutations were detected by PCR. For the pediatric group, a positive correlation was observed between WBC count and the presence of FLT3-ITD in patients with AML and ALL. Furthermore, children with AML who had the FLT3-ITD mutation showed a tendency to express CD34 in blast cells. In the adult group, the AML patients with FLT3-ITD who expressed CD34 in blast cells had a tendency to worse progression. The present data indicate no association between the prognostic factors evaluated and FLT3 gene mutations in adult with AL. Yet, the presence of FLT3-ITD mutation was significantly related with WBC count in the pediatric group. These findings demonstrate that FLT3 gene mutations can be considered as independent poor prognostic factors.