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The Real Role of Genetics in Breast Cancer

Breast Cancer

Photo Credit: Flickr/Bob Richmond

The Real Role of Genetics in Breast Cancer

By Carolyn Hauck on October 22, 2015

When Google co-founder Sergey Brin found out that he had the gene mutation for Parkinson’s Disease through genetics testing, he announced the news publicly. According to scientists, the gene mutation would increase his risk of getting Parkinson’s Disease by 30-75%. It’s the sort of story that goes hand-in-hand with the developing field of genetics and health. But are those sorts of statistics the kind you find with every disease? Take breast cancer for example.

Most women who develop breast cancer do not have one of the hereditary genes that cause breast cancer. Women who develop breast cancer from genetics are in the minority--roughly 5-10% of all breast cancer cases.

While there are other abnormal genes related to breast cancer, the primary genes involved in most hereditary breast cancers are abnormal BRCA1 and BRCA2 genes. These stand for Breast Cancer 1 and 2 respectively. Women who carry this gene may account for up to 10% of all breast cancer cases, and could have up to an 80% chance of developing breast cancer, but when you take into consideration that genetics only accounts for 10% of all breast cancer cases, you start to wonder whether you need to worry about the role of genetics in breast cancer.

Dr. David on JustAnswer confirms that 90% of patients who have breast cancer have no family history of breast cancer. So, he says, you don't have to stress as much about the role of genetics in breast cancer as you might think.

According to Breastcancer.org, you are more likely to have an abnormal breast cancer gene if:

  • You have blood relatives on either your mother's or father's side of the family who had breast cancer diagnosed before age 50.

  • There is both breast and ovarian cancer in your family, particularly in a single individual.

  • There are other gland-related cancers in your family such as pancreatic, colon, and thyroid cancers.

  • Women in your family have had cancer in both breasts.

  • You are of Ashkenazi Jewish (Eastern European) heritage.

  • You are African American and have been diagnosed with breast cancer at age 35 or younger.

  • A man in your family has had breast cancer.

While it’s important, and sometimes necessary, to know your family’s health history, genetics can play a lesser role than we think when it comes to a particular disease.