Biomedical subjects

António E Pinto

Publications and source records attributed to António E Pinto.

5 recordsLinked to original sources

PubMed2006

DNA flow cytometry but not telomerase activity as predictor of disease-free survival in pT1-2/N0/G2 breast cancer.

OBJECTIVE: In the subgroup of patients with node-negative (N0) moderately differentiated (G2) breast cancer, the clinical decision of giving adjuvant therapy is critical. The aim of this study was to investigate the prognostic value of biomarkers (DNA flow cytometry and telomerase activity in correlation with routinely used estrogen receptors (ER) and HER oncoprotein) in pT1-2/N0/G2 breast cancer, for improving therapeutic management. METHODS: The series involved 135 patients with pT1-2/N0/G2 breast cancer and median follow-up of 58.5 months. DNA ploidy and S-phase fraction (SPF) ( 10%) were assessed on frozen samples. Telomerase activity, ER and c-erbB-2 expression were analyzed by standardized immunohistochemistry techniques. A Cox regression analysis was performed for prognostic evaluation. RESULTS: Aneuploidy significantly correlated with high SPF and lack of ER, while high SPF showed significant correlations with high telomerase activity, c-erbB-2 overexpression and absence of ER. Kaplan-Meier curves showed significant differences for ploidy and SPF in relation with disease-free survival (DFS) and overall survival (OS), and a statistical trend for ER. By Cox regression analysis, DNA aneuploidy (RR = 16.7; p = 0.007) and high SPF (RR = 23.1; p = 0.004) revealed significant correlations with worse DFS. Among patients with diploid (n = 76) and low/intermediate SPF (n = 85) tumors, only one had recurrence of the disease. No association between telomerase activity and clinical outcome was observed. CONCLUSION: In pT1-2/N0/G2 breast cancer patients, DNA ploidy and SPF are relevant prognostic biomarkers that should be considered as additional tools in the therapeutic planning.

Adult↗

PubMed2005

Correlations of cell cycle regulators (p53, p21, pRb and mdm2) and c-erbB-2 with biological markers of proliferation and overall survival in breast cancer.

AIM: The biological impact of cell cycle regulatory proteins on breast cancer progression is widely recognised, although mostly unclear. The aim of this preliminary study was to investigate the correlations of several cell cycle modulators (p53, p21, pRb, and mdm2) and c-erbB-2 expression with cell proliferation markers (S-phase fraction [SPF] and Ki-67) and overall survival in breast cancer. METHODS: The series comprised 50 women with stage I-II invasive ductal breast carcinoma (median follow-up 87 months), who were selected for their tumour proliferative characteristics (15 low, 15 high, and 20 intermediate proliferative tumours). Tumour differentiation was assessed following the Nottingham grading criteria. Cell cycle regulators, oestrogen receptor status, and Ki-67 index were analysed by immunohistochemistry on paraffin embedded material (cut-offs 10%). c-erbB-2 was evaluated according to a standardised immunohistochemical assay and borderline cases were confirmed by FISH analysis. Ploidy and SPF were determined by DNA flow cytometry on frozen samples. Chi-square test and Fisher's exact test were applied to analyse the statistical significance of data. RESULTS: Positive immunostaining was observed in nine (18%) p53+, 30 (60%) p21+, 13 (26%) pRb+, and one (2%) mdm2+ cases. c-erbB-2 expression was considered positive in 11 (22%) cases. In the subset of patients dead of the disease, a high incidence of c-erbB-2 over-expression (7/10, 70%) was verified. In general, no significant correlations among cell cycle regulators or between the latter and histopathological or proliferative characteristics were found. Only the p53-/p21+ phenotype significantly correlated with low SPF (p=0.048), and p21 positivity showed a trend to be associated with low SPF (p=0.083). No statistically significant correlations between cell cycle inhibitors and clinical outcome were found. On the contrary, c-erbB-2 over-expression showed significant correlations with DNA aneuploidy (p<0.001), high SPF (p<0.001), high tumour grading (p=0.008), lack of oestrogen receptors (p=0.036), and poor overall survival (p<0.001). CONCLUSIONS: The results seem to indicate the lack of correlations of cell cycle regulatory proteins with cell proliferation markers and overall survival in breast cancer, in contrast to c-erbB-2 over-expression which was found to be associated with increased proliferation rate and worse prognosis.

Adult↗

PubMed2003

Flow cytometric S-phase fraction as a complementary biological parameter for the cytological grading of non-Hodgkin's lymphoma.

Fine-needle aspiration cytology (FNAC) is a technique that can overcome tissue-sampling disaggregation problems related to DNA flow cytometry analysis. The aim of this study, with long-term follow-up (median, 72 mo), was to investigate the prognostic value of DNA ploidy and S-phase fraction (SPF) in patients with non-Hodgkin's lymphoma (NHL), and additionally, the relevance of SPF in the grading of NHLs, using FNAC. The series comprised 76 patients with NHL (32 indolent and 44 aggressive tumors, including 14 Burkitt lymphomas) and 30 patients with reactive lymph node enlargement used as a control group. DNA flow cytometry was performed on fresh samples obtained by FNAC. NHL grading was done according to the updated Kiel classification. The 5-yr overall survival of patients with NHL was determined using the Kaplan-Meier method. All samples of the control group and 81.6% of the NHLs showed a DNA diploid pattern. Fourteen cases (18.4%) were DNA aneuploid with bimodal distribution: slight hyperdiploidy and near-tetraploidy. Despite the higher incidence of aneuploidy in aggressive than in indolent tumors (22.7% vs. 12.5%), no correlation between DNA ploidy and NHL grading was observed. In contrast, SPF revealed a strong correlation with grading (P=0.0001). The mean SPF values varied from 6.5% in indolent NHLs, to 20.4% in aggressive not-otherwise-specified (NOS) NHLs, and to 35.3% in Burkitt lymphomas. Nearly all aggressive NHLs had an SPF >15%, while the vast majority of indolent NHLs showed an SPF <10%. The mean SPF value in the reactive node group was 6.6%. NHL grading significantly was correlated to survival (P=0.004) only if the Burkitt lymphomas, which showed the best prognosis, were analyzed as an independent group. There was a trend that did not reach statistical significance (P=0.072) for a worse clinical outcome of patients with aneuploid tumors. When mean SPF values were used as cutoff points to divide both indolent NHLs and aggressive NOS NHLs into two proliferative subgroups, no differences in relation to survival were found (P=0.763 and P=0.994, respectively). Also, no proliferative difference was verified between indolent NHLs and the reactive lymph node group (P=0.223). These results show that flow cytometric SPF is a valuable complementary parameter for grading NHLs on FNAC samples, but it appears to give no additional prognostic information on subset analyses.

Adolescent↗

PubMed2002

Independent prognostic value of hormone receptor expression and S-phase fraction in advanced breast cancer.

OBJECTIVE: TO assess the prognostic value of immunocytochemically assessed hormone receptor expression and DNA flow cytometry data in advanced breast cancer. STUDY DESIGN: This prospective study with long-term follow-up evaluated the above parameters in relation to overall survival in 392 patients with advanced breast cancer (stages IIB, n = 106; IIIA, n = 66; IIIB, n = 174; and IV, n = 46) using fine needle aspiration cytology. RESULTS: Estrogen and progesterone receptor positivity was detected in 65.1% and 46.1% of the tumors, respectively. DNA aneuploidy was present in 70.9% of the cases, and the median S-phase fraction (SPF) was 9.4%. There was a significant correlation of aneuploidy and high SPF with lack of hormone receptors. The median SPF and SPF tertiles (cutoff values, 6.5% and 12%), applied in the whole series, showed a significant correlation with survival, whereas if SPF was used according to ploidy status, no prognostic significance was found. No differences in relation to survival among different DNA aneuploidy subclasses were verified. In univariate analysis, clinical staging, hormone receptors, DNA ploidy and SPF showed a statistically significant correlation with the overall survival. In multivariate analysis only DNA ploidy did not maintain independent prognostic significance. CONCLUSION: Hormone receptor expression and flow cytometric SPF are independent prognostic factors in advanced breast cancer.

Adult↗

PubMedDate not supplied

[DNA flow cytrometry in solid tumors].

This brief overview outlines the fundamental principles of flow cytometry with emphasis on DNA measurements and cell cycle analysis in human solid tumors. Type of material used, sampling processing procedures and methods of analysis of data are discussed. DNA ploidy and proliferative activity (S-phase fraction) are the two biological parameters commonly measured by DNA flow cytometric analysis. The prime purpose of most studies in this area is the investigation of the prognostic value of DNA flow cytometry in addition to the information provided by conventional clinicopathological factors known to affect disease prognosis. Numerous studies concerning the predictive significance of DNA flow cytometry in some types of solid tumors are reviewed in this article. The general statement, for tumors in the same histopathological stage of the disease, is that diploid and/or low proliferative tumors have a more favourable prognosis than aneuploid and/or high proliferative tumors, suggesting an important role of DNA flow cytometry in the assessment of tumor behaviour and in the outcome evaluation of the disease. However, in some studies this association could not be substantiated, and the prognostic relevance of DNA analysis has been questioned. The potential reasons for conflicting results, namely the methodological pitfalls related to the cell preparation techniques and the histogram interpretation are discussed.

DNA, Neoplasm↗