Organochlorine Compounds in Relation to Breast Cancer, Endometrial Cancer, and Endometriosis: An Assessment of the Biological and Epidemiological Evidence

Abstract

There is an increasing public and scientific concern that certain chlorinated compounds, recognized as environmental pollutants, may cause estrogen-related neoplastic disease in humans. The main hypothesis has been that certain organochlorines, through their estrogenic actions, might cause breast cancer. From experimental studies, both in vitro and in vivo, there is evidence that certain organochlorine compounds may cause estrogenic effects, whereas others may cause antiestrogenic effects. In limited studies, some of these compounds in high doses have also been shown to increase and reduce the frequency of estrogen-related tumors in animals. The epidemiological findings regarding the association between organochlorines and breast cancer are inconclusive. However, the largest and best designed study has been interpreted as negative with respect to DDT and polychlorinated biphenyls (PCB) in relation to breast cancer. Associations between organochlorine exposure and endometrial cancer or endometriosis have even more limited empirical basis. The hypothesis that human exposure to environmental levels or organochlorines would favor an estrogenic overactivity leading to an increase in estrogen-dependent formation of mammary or endometrial tumors is not supported by the existing in vitro, animal and epidemiological evidence. It can, however, not be conclusively rejected on the basis of available data.

Serum organochlorines and breast cancer: a case–control study among African-American women

“…It is possible the relevant organochlorine exposure measure for breast cancer risk might be the woman's body burden at critical periods of breast susceptibility and that current levels do not represent these exposures. Both lactation and body mass index impact levels of organochlorine compounds (6,7). We found no evidence that either factor influenced any relationship of PCBs or DDE and breast cancer risk.…”

“…The organochlorine residues present at the highest concentrations in human adipose tissue, breast milk and blood are dichlorodiphenyldichloroethene (DDE), the metabolite of the pesticide dichlorodiphenyltrichloroethane (DDT), and the non-pesticide class of polychlorinated biphenyls (PCBs) (6). Extensive evidence exists from animal studies of the carcinogenicity of DDT, DDE and PCBs (7). Exposure to DDT and PCBs in mice has each resulted in an increased incidence of cancers of the liver and lung, as well as of lymphoma and leukemia (6,8,9).…”

Time to pregnancy and pregnancy outcome

“…the Baltic Sea) is contaminated by persistent organochlorine compounds (POCs). Indeed, this fish an important source of exposure to POCs in the Swedish population (10)(11)(12). Previous studies had found that Swedish fishermen and their families on average consume more fish than the general Swedish population (10,13,14).…”

Breast cancer in Norway 1970-1993: a population-based study on incidence, mortality and survival

“…Attention has focused an environmental and dietary oestrogens as possible contributors to the increased incidence of breast cancer but the epidemiological findings are inconclusive (Ahlborg et al, 1995;Safe, 1995). However, even though the total amount of environmental and dietary oestrogen is low, it might have an influence over time, especially in adolescent women.…”