Biomedical subjects

Frederique Penault-Llorca

Publications and source records attributed to Frederique Penault-Llorca.

6 recordsLinked to original sources

PubMed2005

Prediction of BRCA1 status in patients with breast cancer using estrogen receptor and basal phenotype.

PURPOSE: To investigate the proportion of breast cancers arising in patients with germ line BRCA1 and BRCA2 mutations expressing basal markers and developing predictive tests for identification of high-risk patients. EXPERIMENTAL DESIGN: Histopathologic material from 182 tumors in BRCA1 mutation carriers, 63 BRCA2 carriers, and 109 controls, collected as part of the international Breast Cancer Linkage Consortium were immunohistochemically stained for CK14, CK5/6, CK17, epidermal growth factor receptor (EGFR), and osteonectin. RESULTS: All five basal markers were commoner in BRCA1 tumors than in control tumors (CK14: 61% versus 12%; CK5/6: 58% versus 7%; CK17: 53% versus 10%; osteonectin: 43% versus 19%; EGFR: 67% versus 21%; P < 0.0001 in each case). In a multivariate analysis, CK14, CK5/6, and estrogen receptor (ER) remained significant predictors of BRCA1 carrier status. In contrast, the frequency of basal markers in BRCA2 tumors did not differ significant from controls. CONCLUSION: The use of cytokeratin staining in combination with ER and morphology provides a more accurate predictor of BRCA1 mutation status than previously available, that may be useful in selecting patients for BRCA1 mutation testing. The high percentage of BRCA1 cases positive for EGFR suggests that specific anti-tyrosine kinase therapy may be of potential benefit in these patients.

Biomarkers, Tumor↗

PubMed2005

Epidermal growth factor receptor, HER-2/neu and related pathways in lung adenocarcinomas with bronchioloalveolar features.

Lung adenocarcinomas with bronchioalveolar features (ABAF), formerly called bronchioloalveolar cancers (BAC), constitute a distinct clinical, radiological and pathological entity among lung malignancies. Epidermal growth factor receptor (EGFR) and to a less extent, HER-2/neu, are known to be overexpressed in non-small lung cancers, but their exact status in ABAF is not well-documented. Stimulation of these two receptors results in the initiation of two major cascades, namely phosphatidylinositol 3-kinase (PI-3K) and Ras-dependent pathways. We have therefore studied the expressions of EGFR, HER-2/neu as well as phosphorylated AKT (pAKT) and phosphorylated extracellular-signal regulated kinase (ERK), which are key molecules in these two pathways, in 15 ABAF patients. EGFR was found to be overexpressed in 9 of 15 patients (60%). HER-2/neu overexpression was detected in 6 of the 14 tumors tested (43%). pAKT and pERK were both found to be positive in 13 of 15 patients (87%). Six of the seven tumors with mucinous pattern were negative for EGFR, while all of the other eight cases were positive (P=0.001). Mucinous tumors were also less likely than non-mucinous tumors to overexpress HER-2/neu (17% versus 63%, respectively). These findings suggest that ABAF, particularly those with non-mucinous histology, commonly harbors EGFR and HER-2/neu overexpression. PI-3K and Ras-dependant pathways that lie downstream are generally activated, even in the absence of EGFR and/or HER-2/neu overexpression. ABAF may be a particularly promising candidate for EGFR-targeted strategies and this possibility merits extensive evaluation in clinical trials.

Adenocarcinoma, Bronchiolo-Alveolar↗

PubMed2005

Patterns of P-glycoprotein activity in the nervous system during vincristine-induced neuropathy in rats.

Vincristine (VCT) is a neurotoxic agent and also a substrate of multidrug resistance (MDR) transporters such as P-glycoprotein (P-gp) and MDR-associated proteins 1 and 2 (MRP1 and MRP2). These proteins are expressed in the central and peripheral nervous systems (CNS and PNS) and normally protect these structures against the harmful effects of VCT. The aim of this study was to elucidate the paradoxical relation between the MDR transporters and the VCT neurotoxicity. With a validated rat model of VCT-induced neuropathy, (1) the expressions of mdr1a (P-gp), mdr1b (P-gp), mrp1 (MRP1), and mrp2 (MRP2) genes were assessed by quantitative real-time polymerase chain reaction, and (2) the transporter activity was monitored using a radioactive tracer, (99m)Tc-sestamibi, in the CNS and PNS. The results showed higher expression of mdr1a and mdr1b genes (x3 and x35, respectively) in the brain than in the spinal ganglia in both control and treated animals. Transporter activity was higher (x10) in the CNS than in the PNS. Hence, P-gp protection may be lower in the PNS than in the CNS, and this may be responsible for the peripheral neurotoxicity of P-gp substrates. VCT treatment increased expression of the mdr1a gene in the CNS and PNS (both x1.7), mrp1 gene in the PNS (x1.7), and transporter activity in both the CNS and the PNS (x4 and x8, respectively). This transporter induction may induce adverse effects when analgesic drugs are administered to treat neuropathic pain.

ATP Binding Cassette Transporter, Subfamily B, Mem↗

PubMed2004

Pathology of ovarian cancers in BRCA1 and BRCA2 carriers.

PURPOSE: Germline mutations in the BRCA1 and BRCA2 genes confer increased susceptibility to ovarian cancer. There is evidence that tumors in carriers may exhibit a distinct distribution of pathological features, but previous studies on the pathology of such tumors have been small. Our aim was to evaluate the morphologies and immunophenotypes in a large cohort of patients with familial ovarian cancer. EXPERIMENTAL DESIGN: We performed a systematic review of ovarian tumors from 178 BRCA1 mutation carriers, 29 BRCA2 mutation carriers, and 235 controls with a similar age distribution. Tumors were evaluated by four pathologists blinded to mutation status. Both morphological features and immunochemical staining for p53 and HER2 were evaluated. RESULTS: Tumors in BRCA1 mutation carriers were more likely than tumors in age-matched controls to be invasive serous adenocarcinomas (odds ratio, 1.84; 95% confidence interval, 1.21-2.79) and unlikely to be borderline or mucinous tumors. Tumors in BRCA1 carriers were of higher grade (P < 0.0001), had a higher percentage solid component (P = 0.001), and were more likely to stain strongly for p53 (P = 0.018). The distribution of pathological features in BRCA2 carriers was similar to that in BRCA1 carriers. CONCLUSIONS: Use of pathological features can substantially improve the targeting of predictive genetic testing. Results also suggest that BRCA1 and BRCA2 tumors are relatively aggressive and may be expected to have poor prognosis, although this may be treatment dependent.

Adult↗

PubMed2003

Prophylactic oophorectomy: a morphologic and immunohistochemical study.

BACKGROUND: The tumorigenesis of ovarian carcinoma is poorly understood. The authors studied morphologic features and immunohistochemical expression patterns of neoplasia-associated markers in prophylactically removed ovaries, normal ovaries, and papillary serous ovarian carcinomas to identify possible preneoplastic changes in ovarian surface epithelium. METHODS: Morphologic features and immunohistochemical expression patterns of CA-125, Ki-67, p53, E-cadherin, and Bcl-2 were evaluated in 21 normal ovaries, 31 ovaries that were removed prophylactically for increased carcinoma risk, and 7 ovarian papillary serous carcinomas. Representative slides from formalin-fixed, paraffin-embedded tissue blocks were submitted to immunohistochemical staining and were evaluated independently by three gynecologic pathologists. For statistical analyses, Fisher exact tests, multivariate analyses, Spearman rank correlation coefficients, Wald statistics, Kruskal-Wallis tests, and Mann-Whitney tests were used. Immunohistochemical staining results were correlated with morphologic findings. RESULTS: The authors found progressive increases in reactivity with the lowest expression in normal ovarian epithelium, stronger expression in epithelium from prophylactically removed ovaries, and the highest expression in carcinomas for Ki-67 and p53. A similar trend was observed for CA-125. Positivity for Ki-67 and p53 was seen predominantly in the epithelium of inclusion cysts and deep invaginations, including those areas that had been identified as hyperplastic or dysplastic on routine hematoxylin and eosin-stained sections. CONCLUSIONS: The current results suggest biologic/molecular evidence for the existence of preneoplastic changes in ovarian surface epithelium and support the previously proposed concept of ovarian dysplasia. Subtle morphologic alterations of the ovarian epithelium may be biologically significant.

Adult↗

PubMed2002

Scarff-Bloom-Richardson (SBR) grading: a pleiotropic marker of chemosensitivity in invasive ductal breast carcinomas treated by neoadjuvant chemotherapy.

The Scarff-Bloom-Richardson (SBR) grade, an important prognostic factor in breast cancer, was also associated with cell proliferation, a consistent indicator of response to chemotherapy. The determination of an association between SBR grade and responsiveness would be clinically useful. We explored the influence of SBR grade on response to neoadjuvant chemotherapy in patients with invasive ductal breast carcinoma. The present study centered on 431 patients registered onto one of four prospective phase II trials. SBR grading was performed according to the Elston method on needle core biopsies prospectively collected prior to treatment from 290 patients and on residual tumour at surgery from 171 patients. The post-operative grades were then compared with those obtained at diagnosis. Univariate and multivariate analysis were used to evaluate the significance of SBR grade on response to neoadjuvant chemotherapy. Both statistical analysis revealed that SBR grade III tumours responded better to neoadjuvant treatment than SBR grade I (p<10(-6)). None of the other patient and tumour characteristics tested correlated with response. Moreover, tumour responsiveness was significantly related to changes of the SBR grade (p=7 x 10(-3)). As a conclusion, we showed that SBR grade is a strong predictive factor of response to induction chemotherapy in breast cancer, independently of the type of regimen used. The association between evolution of the histological grade following chemotherapy and response to treatment may prove valuable for clinicians as they make their decision regarding patient therapy.

Adult↗