Environmental risk of breast cancer is focus of a new Cornell program

A new synthesis and public-information program starting up at Cornell University will examine the environmental risk factors -- including exposure to chemical pesticides -- for breast cancer in women of New York and the United States.

Prompted by concern from U.S. Sen. Alfonse D'Amato (R-N.Y.) about higher-than-average "clusters" of breast cancer in some regions of the state, the Cornell program will interpret and disseminate research information on both the established and suspected risk factors for the disease. Plans also call for creation of a publicly accessible database, within the Pesticide Management Education Program (PMEP) at Cornell, covering chemical pesticides and their sales and use in New York. In his Jan. 3 State of the State address New York Gov. George Pataki said he is requesting an appropriation of $250,000 for the program.

Already, the program is bringing together representatives from a spectrum of stakeholders -- advocacy groups, medical and public-health professionals, lawmakers and public officials, scientists, educators, agricultural and agribusiness professionals and concerned citizens -- who share a common goal: reducing the incidence of breast cancer.

"This will become a unique resource that is not now available anywhere in the world, an accessible synthesis of credible information for the scientific and general public," said June Fessenden MacDonald, Ph.D., chair of a faculty and staff group responsible for the Cornell University Program on Breast Cancer and Environmental Risk Factors in New York State.

"Understanding the issues and making sense of the latest research findings are essential for informed decision- making, both on the public-policy and the individual level," MacDonald said, noting that the program will operate from the Institute for Comparative and Environmental Toxicology (ICET) in the Cornell Center for the Environment.

"Until recently, there were only a few, small studies looking at the role of environmental chemicals in breast cancer," said Suzanne M. Snedeker, Ph.D., project leader and an expert in reproductive toxicology and mammary gland biology. "However, in the last two or three years, several major studies were begun with thousands of women on Long Island and elsewhere in the United States. There will be an information explosion when these studies are complete, and we will be ready to help interpret the results."

"Information will start flowing as soon as we get it," promised program Chair MacDonald, who also is Cornell associate professor of biochemistry, molecular and cell biology. Research summaries and critical evaluations will be published in fact sheets, brochures, and electronic documents and databases available on the Internet, she said. Electronic communication, including a World Wide Web home page for the program, will make the program more responsive on critical issues to the public it serves, MacDonald said.

"A complex issue, such as the multiple causes of breast cancer, calls for a multidisciplinary approach, and that's where Cornell, the state's land grant university, can excel," said Daryl B. Lund, Ph.D., dean of Cornell's College of Agriculture and Life Sciences (CALS). Besides CALS, Cornell faculty and staff members are coming to the breast cancer program from the College of Human Ecology, College of Veterinary Medicine, College of Arts and Sciences, the divisions of Nutritional Sciences and Biological Sciences, Cornell Cooperative Extension, and in New York City, the Cornell University Medical College and the Strang-Cornell Cancer Prevention Center.

"We have at Cornell the range of expertise -- from toxicology, pesticide management and food science to cancer prevention, risk assessment and communication -- to tackle this issue," said R. David Smith, Ph.D., associate director of Cornell Cooperative Extension. "Our job will be to bridge the gaps, to translate data to information that will be useful to New York's citizens and its public-policymakers." Compilation and review of all the information currently available may reveal gaps in the knowledge base about breast cancer's causes and point to new research directions, noted Rodney R. Dietert, Ph.D., director of the Cornell department where the program is based, the Institute for Comparative and Environmental Toxicology in Ithaca. One research need, he said, may be a better understanding of the so-called "biomarkers" that indicate individuals' previous exposure to specific chemicals.

"Of course it is useful to know the geographic areas where pesticides have been applied or the soils and drinking water supplies where chemical residues are found," said Dietert, a professor of immunogenetics and senior fellow in the Cornell Center for the Environment. "But biomarkers will tell us much more about each individual's chemical load, just as testing children for lead tells us more about their problem than does a report on leaded gasoline sales in their area." Biomarkers of another kind, the early cellular changes that precede tumor formation, are the subject of study for researchers at Cornell University Medical College, explained Jerome J. DeCosse, M.D., Ph.D., a surgeon who is the Lewis Thomas University Professor and chair of the Cancer Care and Research Program. "For example, reducing dietary fat consumption appears to alter cancerous biomarkers in a favorable direction," DeCosse said, noting the hospital's emphasis on education for risk reduction.

Cornell Medical College scientists also are collaborating in the National Cancer Institute-funded "Long Island Breast Cancer Study Project," which is examining the role of environmental and occupational factors in the development of breast cancer.

"The program will tap Cornell Cooperative Extension to inform people about the current knowledge of diet-related risk factors," said Cutberto Garza, M.D., Ph.D., director of the Cornell Division of Nutritional Sciences in Ithaca. "Some of the research findings still need more investigation," he said, pointing to inconclusive studies of high-fat diets and low vitamin C and E levels as risk factors for breast cancer. The nutritionist noted that other diet-related factors -- such as obesity, alcohol consumption and eating diets that are low in fiber, carotenoids and vegetables -- are increasingly viewed as potentially contributing to breast cancer.

Many experts agree on at least six "established" risk factors for breast cancer, according to Program Leader Snedeker, who served as a toxicologist at the National Institute for Environmental Health Sciences (NIEHS) before joining the Cornell faculty, and exposure to chemical pesticides is not one of the established risks. (These generally acknowledged risk factors are age, with incidence of breast cancer increasing in older women; early menarche, the onset of sexual maturity; late menopause; late age of first birth; family history; and high socioeconomic status.) "However, established risk factors don't appear to completely explain the high incidence of breast cancer, especially high 'clusters' of breast cancer in certain geographic regions," Snedeker said. "This leads some investigators to question the role of environmental factors, such as diet and the role of environmental chemicals, including pesticides, in determining breast cancer risk. Of particular interest are chemicals and pesticides that mimic the action of the female hormone estrogen.

"Most studies done in the past have concentrated on comparing levels of certain persistent organochlorine chemicals, such as DDT, in the blood or breast fat of breast cancer patients and controls," Snedeker noted. "The results of these studies have not been conclusive, but they have stimulated interest and much-needed research on the role of pesticides in breast cancer."

"Farmers and other pesticide applicators feel unfairly singled out because the causal relationship between pesticides and cancer may be weak when compared to other factors," said Michael P. Voiland, Ph.D., senior legislative associate for Cornell University and a specialist in environmental issues. "However, breast cancer interest groups feel that baseline information on potentially cancer- causing environmental factors, such as pesticide exposure, should be more accessible."

One solution that should suit advocacy groups as well as pesticide applicators would be a computer-based, easily accessible repository of data on pesticide use in the state, suggested William G. Smith, senior extension associate in Cornell's Pesticide Management Education Program. The database would make public a variety of information about pesticides used on commodities, general agricultural pesticide uses on food crops, and non-food pesticide use, including landscape and lawn care. The database could be maintained by the university and be accessible through CENET, the Cornell Cooperative Extension Electronic Network, Smith said.

Formation of the program resulted from a request by D'Amato to Cornell President Hunter Rawlings. Previous discussions among D'Amato, State Sen. Michael J. Tully Jr. (R-7th) and breast cancer interest groups had heightened concern about "clusters" of breast cancer on Long Island and measures necessary to reduce the occurrence of the disease. The university's assistance was sought in advancing understanding and cooperative efforts among the concerned parties. Some residents of Long Island's Suffolk and Nassau counties suspect a link between pesticides and breast cancer, according to Tully.

"The existence of cancer clusters is undeniable, even if their meaning is not clear," said MacDonald, and there seem to be definite trends in breast cancer. For example, a study recently published in the Journal of the National Cancer Institute indicated that the northeast United States appears to have a 30 percent higher breast cancer rate than does the South. Yet, only about half the difference between the Northeast and South can be explained by known risk factors, Snedeker said.

Whether pesticides in the air, water or food turn out to be a contributing cause of breast cancer remains to be seen, MacDonald said. "The important thing is that the governor and other elected officials are taking a women's health problem seriously.

"Now it's up to us to gather this information," she said, "to put it in an understandable form for a technical and a lay audience, to identify areas that need further study, and to get the information into the hands of those who need to make decisions."  

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