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Biomedical subjects

Philippe Beuzeboc

Publications and source records attributed to Philippe Beuzeboc.

22 records · Page 2Linked to original sources

[Targeting epidermal growth factor receptor in cancer of the breast].

The erbB receptor family is part of the receptor tyrosine kinase superfamily and consists of four members erbB. The erbB receptor family has been shown to play an important role in both the development of the normal breast and the pathogenesis and progression of breast cancer. Receptor overexpression has also been shown to be a negative prognostic indicator and to correlate with both tumor invasiveness and a lack of responsiveness to standard treatment, both chemotherapy and hormonotherapy. The targeting of EGFR mainly resides in two approaches: tyrosine kinase inhibition and monoclonal antibodies blocking ligand fixation. Many experimental data support the potential role of targeting EGFR in breast cancer. Particularly tyrosine kinase inhibitors demonstrates activity as single agent or in association with hormonotherapy, chemotherapy and trastuzumab. The association of Iressa with hormonotherapy points out that theses agents may prevent or differ hormonoresistance. Moreover studies in situ carcinoma suggest that tyrosine kinase inhibitors may play a role in chemoprevention. So, targeting EGFR may be indicated in a large spectrum of breast tumors from early to advanced stages, hormone negative or positive breast tumors. However the complexity of erbB network requires the targeting of multiple molecular sites within the network and the characterization of tumor profiles in order to optimally select patients for these therapies.

Antibodies, Monoclonal↗

HER2 status in patients with breast carcinoma is not modified selectively by preoperative chemotherapy and is stable during the metastatic process.

BACKGROUND: The objective of this study was to determine whether HER2 expression levels in breast carcinomas were modified by chemotherapy or during the metastatic process. METHODS: HER2 expression was analyzed on sequential tissue specimens taken from the primary tumor before patients received preoperative chemotherapy (CT) and from post-CT residual breast tumor or at a metastatic site. The first group of patients included 59 women who presented with T2-T4,N1-N2 breast carcinoma and were treated by preoperative anthracycline-based CT and then underwent surgery. The second group included 44 patients with metastatic breast carcinoma localized to the lung (27 patients) or to the liver (17 patients). HER2 status was determined by immunohistochemistry using an anti-p185(HER/neu) monoclonal antibody and was classified as overexpressed or not overexpressed. RESULTS: Among the patients who received preoperative CT, HER2 overexpression was observed in 15 of 59 patients (25%). A complete pathologic response was observed in 2 of these 15 patients. HER2 still was overexpressed in 11 of 13 remaining residual tumors and was no longer detectable in 2 tumors. In addition, the 29 tumors with no HER2 overexpression before CT remained negative after treatment. In patients with metastatic breast carcinoma, HER2 was overexpressed in 11 of 44 primary tumors (25%). In 9 of these 11 tumors, HER2 overexpression was maintained in the metastases (9 pulmonary metastases and 4 hepatic metastases). In two patients who had low levels of HER2 overexpression in their primary tumors, no staining was observed in the secondary tumor (one pulmonary tumor and one liver tumor). There were no tumors in which the overexpression of HER2 was found only in the metastasis. CONCLUSIONS: The current study showed that, in most patients, HER2 overexpression was unchanged after CT and in metastatic sites. No HER2 negative primary tumors became HER2 positive after patients received CT or during the metastatic process. In a few patients, a diminution in the level of HER2 expression was observed after CT or in secondary tumors. This may have been due to a transitory state of altered tumor cells or to the selection of HER2 negative tumor cells clones.

Adult↗

Circulating macrophage colony stimulating factor as a marker of tumour progression.

Tumour expression of the macrophage colony stimulating factor (CSF-1 or MCSF) has been associated with an adverse prognosis in breast cancer, through an effect on the promotion of metastasis. The aim of the present study was to evaluate the clinical relevance of high circulating CSF-1 levels in patients with newly diagnosed breast tumours and correlate CSF-1 with clinico-pathological parameters. A secondary aim was to also measure CSF-1 in patients with other tumour types and at different stages of disease. Using a commercially available ELISA, pre-treatment plasma levels of CSF-1 were assessed, in 471 consecutive patients diagnosed with breast tumours, in 70 patients with newly diagnosed cancer of the head & neck, in 32 men with prostate cancer metastatic to bone and in 39 women with advanced metastatic breast cancer. Mean CSF-1 levels were significantly higher in patients with locally advanced (p <.015) or metastatic breast tumours (p <.048) and in a group of primary breast cancer patients (n = 26) selected for intensive chemotherapy because of multiple adverse tumour characteristics (p <.0002). Mean CSF-1 was also higher in patients younger than 35 years (p <.02) and in post-menopausal patients (p <.03). There was no significant association with tumour histologic type, grade, or other individual histopathologic parameters. No significant association was found between pre-treatment CSF-1 and overall/relapse free survival. Median CSF-1 levels were dramatically higher in patients with newly diagnosed tumours of the head & neck (604 pg/ml), in men with prostate cancer metastatic to bone (627 pg/ml) and women with advanced metastatic breast cancer (867 pg/ml) than those seen in patients with newly diagnosed breast tumours (334 pg/ml). Our data support the hypothesis that CSF-1 may play a functional role in tumour progression to metastasis as has previously been reported in animal models.

Biomarkers, Tumor↗