A woman’s biologic age, which is actually a DNA-based estimate of a person’s age, is linked to the future development of breast cancer, according to researchers at the National Institutes of Health (NIH). In fact, the study in the Journal of the National Cancer Institute shows that for every five years that a woman’s biologic age is older than her actual age, she faces a 15% increase in her chances of developing breast cancer.
“Age is one of the strongest predictors of cancer, chronic disease and mortality, but biological responses to aging differ among people,” the study authors wrote. “Epigenetic DNA modifications have been used to estimate ‘biological age,’ which may be a useful predictor of disease risk.”
To test this hypothesis for breast cancer, the researchers used a case-cohort approach to measured baseline blood DNA methylation of 2,764 women enrolled in the Sister Study, 1,566 of whom later developed breast cancer after an average of six years. The researchers defined biological age acceleration for each study participant by comparing her estimated biological age with her chronological age. All the statistical tests were two-sided, and both hazard ratios and 95% confidence intervals for breast cancer risk were estimated using Cox regression models.
What Did The Study Find?
Scientists working at the National Institute of Environmental Health Sciences theorized that biologic age could be linked to environmental exposures and speculated that if this were true, it could be an indicator of disease risk. They used three different measures to calculate biologic age, measuring methylation located at certain locations in DNA. The team of researchers measured methylation in a subset of 2,764 women, none of whom had breast cancer at the time their blood samples were taken.
“We learned that if your biologic age is older than your chronologic age, your breast cancer risk is increased,” explained Jack Taylor, MD, PhD, and study author, explained in a phone interview. “We don’t know how exposure and lifestyle factors affect your biologic age or whether this process is reversible.”
The researchers found the biological age acceleration was linked with an increased risk of developing breast cancer. While biological age may accelerate with menopausal transition, age acceleration in both premenopausal and postmenopausal women predicted future breast cancer development, the authors wrote.
In their conclusion, the authors wrote: “DNA methylation-based measures of biological age may be important predictors of breast cancer risk.”
What Does This Mean For Healthcare Providers?
For physicians, the research study is not yet important to their practice, Dr. Taylor says. “This is because it is a research study and we are on the initial step of this research,” he says. “What we don’t know yet are what are the things that advance your clock, and if it is advanced, what are the things that you can do to turn it back.”
“While this is certainly an avenue of research that is of interest to physicians as well as to the public, it’s not at the point where physicians can offer their patients any screening tests that might help them to detect their breast cancer risk,” Dr. Taylor said. “For now, we have good advice in terms of exercise, diet, and maintaining a healthy BMI. These are still the touchstones of good medical practice when it comes to breast cancer.”
Last updated on 9/27/19.