Study: No Strong Link Found Between Breast Cancer and Environment

A study of the high rates of breast cancer found on Long Island has failed to find a strong link between breast cancer and environmental pollution.

A pattern of high death rates for female breast cancer extending from the Mid-Atlantic through the Northeastern states has persisted for many years. The number of breast cancer cases newly diagnosed each year in this region has also been above the U.S. average.

The Long Island Breast Cancer Study Project (LIBCSP) has been studying 1,508 women in Nassau and Suffolk counties to see if certain environmental contaminants increase the risk of breast cancer.

Researchers found that organochlorine compounds, chemicals found in pesticides, were not linked with the elevated risk of breast cancer on Long Island. However, researchers believe that it is possible that breast cancer risk in some women may be linked with exposure to the chemicals due to individual differences in metabolism and ability to repair DNA damage.

Exposure to polycyclic aromatic hydrocarbons (PAH), a pollutant caused by incomplete combustion of chemicals including diesel fuel and cigarette smoke, was associated with a modest increased risk for breast cancer. Women who had the highest levels of PAH-DNA levels had a 50 percent increased risk for breast cancer compared to women with the lowest levels, according to the study published in the journal Cancer Epidemiology, Biomarkers and Prevention.

But a 50 percent increased risk is considered modest as a family history of breast cancer increases a woman's risk by 100 to 200 percent.

Research will continue to further study the impact of the environment on the risk of breast cancer, including exposure diversity in the environment, the importance of the timing of exposure, and the role of genetic susceptibility.

Other sources: National Cancer Institute