COMMON QUESTIONS ABOUT BREAST CANCER: WHAT ARE THE ENVIRONMENTAL RISK FACTORS?
Environmental hazards are perhaps the least-understood risk factors associated with breast cancer. We do know that exposure to repeated low or modest levels of radiation increases the risk of developing breast cancer. Women who have received upper-body radiation or multiple X-ray procedures may be at increased risk. But repeated single diagnostic procedures and repeated mammograms involve only low doses of radiation and at this time are considered insignificant as risk factors.
Other environmental causes are speculative. Exposure to high-voltage electrical power lines or appliances (electromagnetic radiation) is currently being evaluated as a possible underlying cause of many forms of cancer, such as childhood leukemia and brain cancer. In most of these cases, the children have been found to live or play near a power substation or high-voltage overhead lines. Further studies are required before any direct association can be made between electromagnetic radiation and a variety of cancers, including breast cancer.
It has become evident that pockets of breast cancer exist in certain geographic areas, such as Long Island, New York. Environmental factors may be involved, because most of the women who are afflicted do not have other risk factors. Whether affluent women have different dietary habits, tend to bear children later in life, incur increased exposure to electromagnetic radiation from multiple household appliances, or experience unknown environmental toxins (such as pollutants in drinking water or pesticides) remains uncertain. To date, the studies evaluating the high-risk pockets have failed to demonstrate an environmental cause for the higher incidence of breast cancer documented in these areas.
Recent media reports suggest that exposure to at least one environmental toxin (the pesticide DDT) may be linked to a fourfold increase in the incidence of breast cancer. This subject requires further scientific research. Because many environmental toxins accumulate in fish and animal fat, avoidance of fish from areas known to be polluted and a diet low in animal fat may help to reduce the risk of exposure to toxins. Although the use of DDT has been banned by the government for years, its long-term effects are only now being recognized. The cancer-causing potential of pesticides and other chemical products in use today may be hidden for years to come. Utilization of environmentally friendly products— and prudent use of all chemicals—may help to alleviate at least some of the risk for future generations.
Although many of the elements mentioned above have been associated with breast cancer, it is important to remember that only one-third of the women who develop breast cancer have known risk factors. In addition, although family history of breast cancer is high on the list of risk factors, approximately 75 percent of the women who develop breast cancer have no such history.
Following surgery and perhaps radiation therapy, most patients feel a sense of relief that their cancer is gone and they can resume their normal lives. Yet often there is one last hurdle: treatment with chemotherapy or hormone therapy to prevent recurrence of the cancer. There is a measure of contradiction in the administration of harmful drugs at a time when the patient is just beginning to feel healthy. The short-term toxic effects (such as loss of hair) seem particularly devastating at this stage, but the lifesaving value of these agents over the long term is vastly more important.