Human breast biomonitoring and environmental chemicals: use of breast tissues and fluids in breast cancer etiologic research

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.

Solid phase microextraction, mass spectrometry and metabolomic approaches for detection of potential urinary cancer biomarkers—A powerful strategy for breast cancer diagnosis

“…Numerous risk factors for breast cancer have been identified, such as hormone-related, and the only well-established diet-related risk factors: obesity and alcohol consumption [2,4,5]. Other factors include inheritance of high-penetrance susceptibility genes, increasing age, exposure to ionizing radiation, family history of breast cancer, higher socioeconomic status, and prior benign breast disease [6]. Taking into consideration genetic susceptibility, two major genes are associated to breast cancer: BRCA1 and BRCA2.…”

“…Environmental factors, including exposure to xenobiotic compounds, diet, electromagnetic fields, and lifestyle have been the subject of numerous scientific inquiries [6]. According to LaKind et al [6] the timing of exposure to environmental risk factors is an important consideration when studying breast cancer etiology.…”

“…According to LaKind et al [6] the timing of exposure to environmental risk factors is an important consideration when studying breast cancer etiology.…”

The physiology of the normal human breast: an exploratory study

“…Recent studies have focused on examination of xenobiotic substances in breast milk for the purposes of determining the type and extent of environmental toxins that are entering breast tissue and their link to breast cancer risk [2,21]. Our data suggest that the presence of toxins in milk does not necessarily reflect toxin exposure in nonlactating breast tissue, and thus intimate that direct examination of ductal fluid would be a more appropriate strategy for evaluating toxin exposure in the breasts of nonlactating women.…”

“…This is despite the undeniable yet inadequately defined ramifications of exposure of nonlactating breast tissue to various carcinogens [20,21]. One hypothesis for the etiology of breast cancer posits that carcinogens enter the breast ductal fluid but are not rapidly cleared.…”