Hormones and weight 'biggest indicators of breast cancer risks'

Washington, Dec 8 (ANI): Undergoing hormone replacement therapy or being overweight are among the biggest underlying causes behind breast cancer while other factors like certain chemicals do not have a major impact on the disease, researchers say.

According to Institute of Medicine researchers, women could, for example, avoid unnecessary medical tests that involve radiation, skip certain types of post-menopausal hormone replacement therapies, drink alcohol in moderation, exercise and maintain a healthy weight and not smoke.

The authors asserted that ionizing radiation from medical diagnostic tests, estrogen-progestin hormone replacement therapy and being overweight are well-established risk factors uncovered in previous studies and for the purposes of their research, they determined environmental factors can be anything not determined by DNA.

But scientific evidence is less conclusive about other environmental factors, such as exposure to the chemicals benzene, 1,3-butadiene and ethylene oxide, found in such common substances as tobacco smoke and gasoline fumes, ABC News reported.

"The epidemiologic evidence is more limited, contradictory or absent," the researchers said.

"Evidence from animal or mechanistic studies sometimes adds support to the epidemiologic evidence or suggests biologic plausibility when human evidence is lacking for a particular factor."

The researchers also revealed that hair dyes and ionizing radiation from cell phones and other devices did not impact a woman's risk for breast cancer.

Despite their findings, the authors said that since exposure varies from woman to woman, so does potential risk.

The report also provides as further evidence that for breast cancer, the environment plays a much bigger role than genetics.

"The report highlights the true complexities of the various risk factors for breast cancer, including our own genetic profiles, our risks of individual exposure to potential cancer-causing factors in the environment and other risk factors that we can and cannot reasonably control," said Robert J. Schneider, co-director of the Breast Cancer Research Program at NYU Langone Medical Center.

"The focus of much of the breast cancer research is on something other than the environment," said Dr. Stefan Gluck, professor of medicine at the University of Miami's Miller School of Medicine. (ANI)