72 New Breast Cancer Gene Mutations Discovered

While previous studies have pointed to BRCA1 and BRCA2 genes as the two main indicators of one’s likelihood of developing breast cancer, a recent study has shown there may be more genetic factors at play than thought.

How Do Genes Play a Role in Breast Cancer?

Breast cancer will affect roughly 12% of the American population – however 40-60% of those with a BRCA1 mutation and up to 45% of those with a BRCA2 mutation will develop breast cancer by age 70.

The Latest Discovery

OncoArray Consortium, an international group of nearly 600 researchers, studied the blood samples of some 300,000 women, about half of whom have had breast cancer.

Through studying their DNA, they were able to pinpoint 65 of the newly identified genetic variants in common between women who have had breast cancer; the other 7 mutations are linked to a predisposition to developing a certain kind of cancer called ‘estrogen-receptor-negative’ breast cancer, which doesn’t respond to hormonal therapies like other types of breast cancer.
Are Each of These Mutations as Concerning as BRCA1 and BRCA2?

Jacques Simard, study author and professor at the Université Laval, Quebec City, says ‘the newly discovered mutations only slightly — by anywhere from 5% to 10% — increase a woman’s risk of developing breast cancer.’

However, that is the effect of one such mutation – a combination of these “risk variants may identify a small proportion of women who are at 3-times increased risk of breast cancer.”

What Does That Mean for Women?

While past estimates have put hereditary breast cancer as making up about 10% of diagnoses, this new information suggests that estimate may be too low.

Currently, breast cancer screening guidelines rely heavily on patient age, but this research suggests that genetic screening may need to be increasingly used for early detection of breast cancer, and other cancers with a high hereditary link.

Genetic testing is becoming more and more affordable; if your mother, grandmother or aunts have developed breast or ovarian cancer, it is worth speaking to your doctor about assessing your family history and deciding if you should be tested. They will be able to tell you if you need genetic testing and support you through the process.

Sources:

1. https://www.cancer.gov/about-cancer/causes-prevention/genetics/brca-fact-sheet#q2
2. https://www.cnn.com/2017/10/23/health/72-new-breast-cancer-mutations-study/index.html