Organochlorine Pesticides in the Females Suffering from Breast Cancer and its Relation to Estrogen Receptor Status

Abstract

Breast cancer is one of the most common types of cancer that occurs in females. Approximately 70% of breast tumors express the estrogen receptor. To date, established risk factors for breast cancer are only partially able to explain the causes for this disease. There have always been researchers’ interests in evaluating the role of environmental chemicals, especially those with evidence of being hormonally active agents, which play an important role in breast cancer development. Organochlorine pesticides are one of those chemical which have received the most attentions because of their ability to concentrate onto food chain, fat-soluble and estrogenic activity while remaining persistent in the human body and environment. The present study is an attempt to explore the possibility and role of organochlorine pesticides in the development of estrogen receptor breast cancer. A hospital-based case-control study was administered on 93 women, who underwent various surgeries for breast diseases, to observe the association between organochlorine pesticide exposures with reference to estrogen receptor status in the subjects suffering from breast cancer. Samples of blood, tumor and surrounding adipose tissue of the breast were collected from the subjects with estrogen positive, estrogen negative and benign breast lesions. The samples were then analyzed to determine the presence of organochlorine pesticides by using a gas–liquid chromatography equipped with an electron capture detector. The α, β, γ and δ isomers of HCH (Hexachlorocyclohexane) and metabolites of DDT (Dichlorodiphenyltrichloroethane) such as p,p’-dichlorodiphenyltrichloroethane (p,p-DDT), o,p’- dichlorodiphenyltrichloroethane (o,p’-DDT), p,p’- dichlorodiphenyldichloroethylene (p,p’-DDE), and p,p’-dichlorodiphenyldichloroethane (p,p’-DDD) were frequently detected in the samples at significant level. The result of this study shows that the exposure to potential estrogenic organochlorines may cause the development of estrogen receptor positive breast cancer. A possible mechanism on prognosis of hormone responsive breast cancers needs to be clarified.