Interview has been edited for clarity.
Can genetic testing identify a gene that causes breast cancer?
Dr. Thompson says there have been a number of genes discovered that predispose people to the development of breast and other cancers. “We inherit these genes from our parents. Anyone can be tested to see if they have one of these genes. Testing requires the collection of a blood or saliva sample.”
If a person is found to have one of the genes that increases their risk of developing breast cancer, then they are usually recommended to undergo enhanced breast cancer screening, which typically means screening every six months with either mammogram or breast MRI.
There are a number of genetic mutations that increase breast cancer risk to a degree but not to a great enough degree that the benefits of mastectomy outweigh the costs.
Depending on the genetic mutation identified, it might also be recommended to consider risk-reducing interventions, such as prophylactic or preventative mastectomies and anti-estrogen medication.
“Whether or not a prophylactic mastectomy is considered depends on which genetic mutation the patient has. If the patient has a mutation that greatly increases their risk of breast cancer, such as the BRCA1 and BRCA2 mutations, then we discuss the benefit of undergoing a prophylactic mastectomy with or without reconstruction,” Dr. Thompson says.
There is no scientific evidence to support taking any specific vitamins or supplements in order to reduce the risk of developing breast cancer.
“However, there are a number of genetic mutations that increase breast cancer risk to a degree but not to a great enough degree that the benefits of mastectomy outweigh the costs.”
Are there any vitamins and supplements that prevent breast cancer?
Dr. Thompson says that there are things that we can do to reduce our risk of developing breast cancer, but we can’t prevent it entirely.
“In regard to vitamins and supplements, there is no scientific evidence to support taking any specific vitamins or supplements in order to reduce the risk of developing breast cancer. For the most part, there is no harm in taking vitamins and supplements, but none of the studies that have been done have found a real impact on breast cancer risk.”
Can regular exercise lower the risk of breast cancer?
There is a theory that extra fat produces extra estrogen, which increases the risk of getting breast cancer, so can regular exercise help?
Dr. Thompson says that regular exercise does appear to be protective when it comes to breast cancer risk, at least in part due to estrogen. “The main source of estrogen in premenopausal people is the ovaries, but fat cells also produce some degree of estrogen. So when someone goes through menopause and their ovaries stop producing estrogen, their fat cells continue to do so.”
In essence, the more body fat they have, the higher their exposure to estrogen. Regular exercise can decrease and maintain low levels of body fat, thereby decreasing the amount of estrogen in the body, which can decrease breast cancer risk.
History of updates
Current version
(15 December 2021)
Reviewed by Dr. Carlie Thompson, Breast surgical oncologist and assistant professor, University of California, California, US
22 October 2019
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