1. ^aLaKind Associates LLC, 106 Oakdale Ave, Catonsville, MD 21228, USA
2. ^bDepartment of Pediatrics, Milton S. Hershey Medical Center, Pennsylvania State College of Medicine, Hershey, PA 17033, USA
3. ^cUS Environmental Protection Agency, Office of Research and Development, National Center for Environmental Assessment, 1200 Pennsylvania Ave, NW (8623N), Washington, DC 20460, USA
4. ^dDivision of Environmental Health Sciences, School of Public Health, University of California, Berkeley, CA 94720, USA

Correspondence: Dr. Judy S. LaKind, LaKind Associates, LLC, 106 Oakdale Avenue, Catonsville, Maryland 21228, USA. Tel.: +1 410 788 8639; Fax: +1 410 788 1971; E-mail: lakindassoc@comcast.net

Received 25 July 2006; Revised 19 September 2006; Accepted 23 September 2006; Published online 14 March 2007.

Abstract

Extensive research indicates that the etiology of breast cancer is complex and multifactorial and may include environmental risk factors. Breast cancer etiology and exposure to xenobiotic compounds, diet, electromagnetic fields, and lifestyle have been the subject of numerous scientific inquiries, but research has yielded inconsistent results. Biomonitoring has been used to explore associations between breast cancer and levels of environmental chemicals in the breast. Research using breast tissues and fluids to cast light on the etiology of breast cancer is, for the most part, predicated on the assumption that the tissue or fluid samples either contain measurable traces of the environmental agent(s) associated with the cancer or that they retain biological changes that are biomarkers of such exposure or precursors of carcinogenic effect. In this paper, we review breast cancer etiology research utilizing breast biomonitoring. We first provide a brief synopsis of the current state of understanding of associations between exposure to environmental chemicals and breast cancer etiology. We then describe the published breast cancer research on tissues and fluids, which have been used for biomonitoring, specifically human milk and its components, malignant and benign breast tissue, nipple aspirate fluid (NAF) and breast cyst fluid. We conclude with a discussion on recommendations for biomonitoring of breast tissues and fluids in future breast cancer etiology research. Both human milk and NAF fluids, and the cells contained therein, hold promise for future biomonitoring research into breast cancer etiology, but must be conducted with carefully delineated hypotheses and a scientifically supportable epidemiological approach.