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Scholarly Communication

Estrogenic microenvironment generated by organochlorine residues in adipose mammary tissue modulates biomarker expression in ERα-positive breast carcinomas

Muñoz-de-Toro, Mónica; Durando, Milena; Beldoménico, Pablo M.; Beldoménico, Horacio R.; Kass, Laura; García, Silvia R. and Luque, Enrique H. (2006) Estrogenic microenvironment generated by organochlorine residues in adipose mammary tissue modulates biomarker expression in ERα-positive breast carcinomas. Breast Cancer Research, 8 . Article Number: R47. ISSN 1465-5411

Available under License Creative Commons Attribution.



Introduction Breast cancer is the most frequent malignant disease in women. Exposure to estrogens throughout a woman's life is a risk factor for the development of breast cancer. Organochlorine compounds (OCCs), such as pesticides and polychlorinated biphenyls, are persistent lipophilic chemicals identified as endocrine disruptors, mainly with estrogenic effects. To test the hypothesis that the amount and quality of organochlorine residues in adipose tissue adjacent to breast carcinoma affect the biological behavior of the tumor, we studied biomarker expression in breast carcinoma and the OCC body burden in patients from an urban area adjacent to Paraná fluvial system, Argentina. Methods The studied patients were 55 women who had undergone excision biopsies of a breast lesion diagnosed as invasive breast carcinoma. Analysis of OCC residues in breast adipose tissue was conducted by electron-capture gas–liquid chromatography. Estrogen receptor alpha (ERα), progesterone receptor (PR) and proliferative activity (Ki-67) levels were measured in paraffin-embedded biopsies of breast tumors by immunohistochemistry. Results All patients had high levels of organochlorine pesticides in their breast adipose tissue. The most frequently detected compounds were p,p'-dichlorodiphenyldichloroethylene, hexachlorobenzene and β-hexachlorocyclohexane. When the whole sample was analyzed, no correlation between ERα or PR expression and OCC levels were found. In the subgroup of ERα- positive breast carcinoma patients, however, there was a positive correlation between PR expression (an estrogeninduced protein) in the neoplastic cells and OCC levels in adipose tissue surrounding the tumor. More significantly, all the ERα-positive breast carcinomas from postmenopausal women exhibited high proliferation when organochlorine levels in the surrounding adipose tissue reached levels higher than 2600 ppb. No associations were found between the organochlorine body burden and any other marker of tumor aggressiveness, such as node involvement or tumor size. Conclusion The present results support the hypothesis that organochlorine residues in adipose tissue adjacent to breast carcinoma generate an estrogenic microenvironment that may influence the biological behavior of the tumor through ERα activation and ERα-dependent proliferation. These findings may have therapeutic implications, since interference between organochlorine compounds and hormonal therapy could be expected to occur.

Item Type:Article
Additional Information:Published: 19 Jul 2006. 9 pages (page numbers not for citation purposes).
Subjects:Q Science > QH Natural history > QH301 Biology
Departments, Research Centres and Related Units:Academic Faculties, Institutes and Research Centres > Faculty of Science > Department of Biological Sciences
Publisher's Statement:© 2006 Muñoz-de-Toro et al.; licensee BioMed Central Ltd. This is an open access article distributed under the terms of the Creative Commons Attribution License (, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
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ID Code:763
Deposited On:01 Jul 2008 16:21
Last Modified:15 Mar 2012 16:50

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