Study of Breast Cancer and the Environment on Long Island
Statement of Marilie Gammon, Ph.D.,
Associate Professor of Epidemiology
School of Public Health
University of North Carolina at Chapel Hill
Before the Senate Committee on the Environment and Public Works
Adelphi University
Garden City, NY
June 11, 2001; 9:00 AM

Good morning Chairman Reid, Senator Clinton, and distinguished members the Committee. I am Dr. Marilie Gammon, of the University of North Carolina at Chapel Hill; formerly of Columbia University in New York. I would like to thank you for inviting me to talk with you about how our environment may influence our cancer risk.

I am the principle investigator of the Breast Cancer and the Environment on Long Island Study*, which is the cornerstone of the Long Island Breast Cancer Study Project (LIBCSP). The LIBCSP, funded by the National Cancer Institute (NCI) and the National Institute for Environmental Health Sciences (NIEHS), is a multistudy investigation of possible environmental causes of breast cancer on Long Island, and is a collaborative effort of New York City and Long Island researchers. My study is investigating whether certain environmental contaminants increase risk of breast cancer among women in Nassua and Suffolk counties. The primary aims are to determine if organochlorine pesticides, including DDT, polychlorinated biphenyls (PCBs), dieldrin, chlordane, and polycyclic aromatic hydrocarbons (PAH), a ubiquitous pollutant caused by incomplete combustion of various chemicals including diesel fuel and cigarette smoke, are associated with risk for breast cancer.

For this population-based study, all women in Nassau and Suffolk counties who were newly diagnosed with breast cancer during a one-year period that ended mid-1997 (cases) were invited to participate. A comparison group (controls) of women who did not have breast cancer were randomly selected from the two counties. Altogether about 1,500 cases and 1,500 controls participated. The study participants completed a questionnaire administered by interview in their homes, and provided pre- and post-treatment blood samples and urine samples. In addition, a random sample of participants who had resided in their homes for at least 15 years participated in a study in which house dust, tap water, and yard soil samples were collected (home study). About 340 cases and 340 controls participated in this component of the study.

Blood and urine samples from 400 of the cases with invasive cancer, 200 of the cases with in situ disease, and 400 of the controls were randomly selected from the study population and analyzed. Laboratory analyses were conducted to measure organochlorine pesticides and PAH-DNA adducts in blood (PAHs bind to DNA), and urinary markers of estrogen metabolism. For the home study, samples were assayed for pesticides and PAHs.

The blood and urine samples of all African-American study participants were analyzed to increase the data available for this group. Further, all African-American women participants who had lived in their homes for at least 15 years were invited to be part of the home study.

Statistical analyses of the questionnaire data are now in progress. These data will be coupled with the results of the laboratory analyses to assess the risk for breast cancer associated with organochlorine pesticides and PAHs. Findings addressing the two primary hypotheses are expected to be published later this year.

Newly undertaken research includes examination of the possible interaction between susceptibility markers and environmental risk factors on risk for breast cancer. Further, tumor and blood markers of estrogen and PAH metabolism are being studied, and the laboratory analyses are now underway. Results from these newer efforts are expected in the year 2002.

I would be pleased to answer any questions you may have.

* The study is sometimes referred to as the Columbia case-control study, because Dr. Gammon began the study while at Columbia University, New York, New York.