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October 2004 Forum Summary
Cancer and Environment Forums

Note: Summaries are available for other forums. See the Forum Summary Archive page for a complete list.

On October 29, 2004, BCERF held its autumn Cancer and Environment Forum in New York City, at the offices of Cornell Cooperative Extension. About 35 participants joined in a day of presentation and discussion, covering themes of comparative cancer models and the newly established Breast Cancer and Environment Research Centers. One sign of the day's success was the intermingling of researchers, agency representatives, and cancer and/or environment activists. A continuing challenge is to provide enough time for dialogue. Evaluation results indicate that the majority of respondents came away better able to understand the relevant research findings and to put this understanding to use in various capacities.

Environmental Risk Factors for Canine and Human Breast Cancer

Dr. John Reif, a graduate of Cornell's College of Veterinary Medicine and Professor of Epidemiology at Colorado State University's Department of Environmental and Radiological Health Sciences, provided a very well received overview of Environmental Risk Factors for Canine and Human Breast Cancer. By way of introduction, he provided a historic perspective outlining the role of animal sentinels in the understanding of human disease. This underscored the promise, for humans, of studying spontaneously occurring canine cancers. Many compelling facts support this approach. For example, humans and companion dogs not only share a common environment, their spectrum of cancers and biologic responses are also similar.

In addition, it is easier in some respects to study canine cancers due to a shorter latency period in canine cancers and the limited geographic mobility of companion dogs. Dr. Reif reported on work in areas such as passive smoke and canine respiratory tract cancer (demonstrating an association), and insecticide exposure and the risk of bladder cancer, showing an association enhanced by obesity. After reviewing what is known about risk factors for human breast cancer, Dr. Reif shared what is known about canine breast cancer, and the various studies elucidating its risk factors. Canine breast cancer is a hormonally mediated cancer, as it is in humans. Canine and human breast cancer also share a similar genetic background and many of the same risk factors. For example, body conformation and early life events (e.g. rates of growth) are related to risk. Dr. Reif's presentation clearly outlined the ways in which animal models are advancing understanding of environmental risk factors for cancer.

Progress Toward Cancer Surveillance and Mapping in Companion Animals on Long Island

Dr. Rodney Page, the Director of the Sprecher Institute for Comparative Cancer Research at the Cornell College of Veterinary Medicine (BCERF's new administrative home) offered an update on the project he leads, mapping companion animal tumors on Long Island. He emphasized that this pilot project is best understood as a springboard for future efforts, aiming, in this phase, to: acquire sufficient data to validate the process; demonstrate the geospatial analytic skills needed for this kind of effort; and, provide preliminary data for future studies. Dr. Page and his group are working with two data sets that contain information reported by veterinary practices (i.e. not residential addresses) on types of cancers diagnosed in cats and dogs. He reports that the work with these data sets demonstrates that this group is able to coordinate the acquisition and processing of large data sets of this type, and to do some preliminary work linking diagnoses and geographic data to display spatial and temporal changes. Dr. Page pointed to the next steps of this project, which are to expand the data and improve reporting - for example, by enhancing lab reporting forms to include more information. He hopes his continued work with the veterinary profession will lead to increased understanding of the value of this work to human health and expansion of efforts such as these.

Breast Cancer and the Environment Research Centers: Advocates and Scientists Working in Partnerships

Long-time breast cancer activist Karen Miller is currently Chair of the Breast Cancer and the Environment Working Group, an advisory group to the Breast Cancer and the Environment Research Centers. Karen spoke to the group about the Centers (detailed further in this issue of The Ribbon) - how they came about, the key role that community grassroots groups played in their formation, and the role community groups are playing in carrying out the production of public health messages based on the Centers' research. In order for a group applying to be a Center to be chosen for funding, they needed to show a history of working effectively with community grassroots groups. One of Karen's key roles is to make connections between the scientists involved, and lay people. She described some of her activities toward this end, as well as her vision for forming the most effective collaborations.

Communicating Environmental Health Sciences Information to Minority Communities

Karli Woods-Mennuti, assistant to Dr. Luz Claudio, Principle Investigator for the Community Outreach and Translation Core, Mount Sinai School of Medicine Breast Cancer and Environment Research Center, provided a wonderful example of one of the Centers' community public health programs. In coordination with the Center at Fox Chase in Philadelphia, this Mount Sinai-based group is working with African American and Latina girls in East Harlem, New York. Karli described this population as having a strong vested interest in the outcome of the scientific studies, which are looking at environmental exposures during critical periods of development. East Harlem has a higher percentage of African Americans, Latinos, and children less than 18 years of age compared to the rest of New York City, as well as higher breast cancer hospitalization rates. Karli described the various offerings the group is providing to the community, such as science and health education workshops and a targeted newsletter, temporarily titled, "ENVIROGIRL" (community input for the title currently being collected!).

Chemicals and Cancer: Predicting Human Cancer from Animal Cancer Bioassays Examples from BCERF

Dr. Suzanne Snedeker, Associate Director of Translational Research at BCERF, and Dr. Heather Clark, Post-doctoral Associate at BCERF, closed out the day with an overview of some of their current work.

Dr. Snedeker began with an overview of the challenge of assessing the cancer risk of chemicals. Risks cannot be characterized until the hazard can be identified and the exposure is understood. The types of data that assist with risk characterization are human epidemiological studies, animal cancer bioassays, and mechanistic data. With the majority of chemicals, there exists little public data in areas such as: all uses, production levels, actual exposures, susceptible periods vis-à-vis exposures, and number of people exposed. This paucity of information is combined with little available data on normal breast development in girls, and that cancers like breast cancer can have long latency periods. Dr. Snedeker then provided information about how animal cancer bioassays are used to overcome some of these obstacles. Some of the advantages of animal cancer bioassays are: they work with highly controlled exposures (which can be varied to examine dose-response relationships); the laboratory animals have shorter life spans; the genetic background of the animals is known; and, there are few confounding factors. Disadvantages include that there are differences in susceptibility and sometimes a lack of concordance in tumor sites; for example, will the chemical that caused liver cancer in a rat cause liver cancer in humans? In the latter area though, Dr. Snedeker points out that there are more similarities than differences. By way of introduction to Dr. Clark's talk, Dr. Snedeker reviewed the features of BCERF's EnviroChem database (ECCD). (See also the overview article in Volume 9, Number 3 of The Ribbon.)

One of the National Toxicology Program (NTP) identified mammary carcinogens (chemicals identified to cause mammary, or breast, tumors in laboratory animals) is ochratoxin-A (OTA). Dr. Clark reviewed the cancer risk of, and potential for exposure to, this naturally occurring toxin and shared her results with the group. Worldwide, OTA is found frequently in stored grain and also in many other food and beverage products. Because of this high potential for exposure and research that points to possible links to several cancers, some researchers and regulatory agencies internationally are beginning to look more closely at understanding and controlling exposure to this toxin. Animal cancer bioassay results are available which show OTA's ability to cause kidney and mammary gland (breast) tumors. Dr. Clark also reviewed the information available on OTA's potential to affect cancer risk in human populations, including a study that investigated a possible relationship between OTA exposure and testicular cancer. This particular study cannot provide evidence of a causal relationship, and no human populations have been studied yet to determine any relationship between OTA exposure and breast cancer risk. In the meantime, some standards of maximum limits of OTA have been set by the European Union, for example, but not in the US food supply. Farm management practices and food processing technologies are being improved to minimize exposure to this naturally occurring toxin. See BCERF Fact Sheet #51 for more information.

Last Update 08.04.05