SAN FRANCISCO—Women in the United States still have a high risk of breast cancer even if they have no genetic predisposition or other commonly-accepted risk factors for the disease, according to a report released today.
“State of the Evidence 2006: What Is the Connection Between the Environment and Breast Cancer?” reports that as many as 50 percent of breast cancer cases remain unexplained by either genetics or lifestyle factors, such as a woman’s age at her first full-term pregnancy or alcohol consumption.
Instead, the report says, “compelling scientific evidence points to some of the 100,000 synthetic chemicals in use today as contributing to the development of breast cancer, either by altering hormone function or gene expression.” The report also identifies radiation exposure, such as that from X-rays and CT scans, as the “longest-established environmental cause of breast cancer.”
“State of the Evidence 2006,” which reviews and analyzes nearly 350 scientific studies on environmental links to breast cancer, was jointly published by two San Francisco-based organizations, the Breast Cancer Fund and Breast Cancer Action. The report was peer-reviewed by leading scientists at the University of Pittsburgh Cancer Institute, Tufts University School of Medicine, Columbia University and other research institutions.
This is the fourth edition of “State of the Evidence;” the 2006 edition reports findings from more than 46 new studies published during 2004 and 2005.
In 2005, breast cancer was expected to kill more than 40,000 women in the United States—one death every 13 minutes—and more than 410,000 women worldwide. U.S. women now have a one in seven chance of being diagnosed with breast cancer during their lifetimes, a risk that has nearly tripled in the past four decades.
“Considerable resources are spent each year to encourage women to make changes in their personal lives that might reduce the risk of breast cancer,” said Jeanne Rizzo, executive director of the Breast Cancer Fund. “But many factors that contribute to the disease lie far beyond a woman’s personal control and can only be addressed by a revolution in thinking on the parts of government and the private sector.”
“This report adds to the compelling evidence that the chemicals we’re exposed to in our daily lives are making us sick,” said Lisa Wanzor, acting executive director of Breast Cancer Action. “Women living with and at risk for breast cancer need public policies that will put our health first and protect us from exposures to toxic chemicals.”
Among the research findings reported in the 2006 edition:
Genetic susceptibility makes only a “small to moderate contribution” to the incidence of breast cancer, according to a re-analysis of a large Scandinavian study originally published in 2000;
An interdisciplinary analysis of the history of hormone replacement therapy revealed that scientists were aware of its breast cancer risk as early as the 1930s. The expert analysts asked why, for decades since the 1960s, millions of women were prescribed powerful pharmaceutical agents known to be carcinogenic;
Women living within one mile of hazardous waste sites containing common herbicides and pesticides such as 2,4-D and chlordane had an increased risk of breast cancer, a study conducted on Long Island, N.Y., found. Researchers working in Iowa and North Carolina also found an increased risk of breast cancer among the wives of farmers who used certain chlorinated pesticides and among those living closest to areas of pesticide application. In California, certain pesticides and herbicides were associated with increased risk of breast cancer in Latina agricultural workers;
There is no safe dose of ionizing radiation. Even the smallest dose has the potential to cause an increased cancer risk in humans, according to a report from the National Research Council; and
Chemicals called phthalates, which are ubiquitous in personal care products, were shown to significantly increase cell proliferation in human breast cancer cells. Scientists also found that certain phthalates inhibited the effectiveness of tamoxifen, one of the most widely prescribed breast cancer treatments, in killing MCF-7 breast cancer cells.
The new report offers a 10-point plan to reduce the risk of breast cancer and ultimately end the epidemic. Among those recommendations:
Establish environmental health tracking programs to monitor toxic exposures at state and federal levels;
Protect workers from hazardous exposures;
Hold corporations accountable for hazardous practices and offer local, state and federal incentives for clean, green practices; and
Create a comprehensive chemicals policy based on the precautionary principle, which would obligate producers of chemical and radiological products to assess the health, safety and environmental impacts of their products before introducing them or releasing them.