This article appears in Paint it Pink 2017.
In the fight for a cure for breast cancer, BRCA1 and BRCA2 get a lot of attention, but many people don’t understand how these genes’ mutations affect their risk of developing the disease.
BRCA1 and BRCA2 (short for BReast CAncer 1 and 2) are human genes that produce tumor-suppressor proteins, according to the National Institutes of Health. These proteins help repair damaged DNA and play a role in cell growth and cell division.
These are genes we all have in our bodies. It’s when these genes have mutations — or mistakes — that a person’s risk rises for developing breast and other forms of cancers, according to Memorial Sloan Kettering Cancer Center.
Only about 5 to 10 percent of all breast cancers diagnosed in the United States are due to inherited gene mutations known to increase risk, according to the American Cancer Society. BRCA mutations affect men, too. Men with BRCA2 mutations are at an increased risk for getting prostate cancer.
A new study published in JAMA reveals how much having “breast cancer genes” increases the risk of cancer. Women with genetic mutations in the “breast cancer genes” have about a 70 percent chance of developing breast cancer in their lifetimes. The findings are based on an analysis of nearly 10,000 women with mutations in either the BRCA1 or BRCA2 gene.
The risk of developing breast cancer varies — it can double — depending on specific mutations within the genes, the study found. Having close family members with breast cancer also increased risk.
Other key findings:
— Among women who had not been diagnosed with breast cancer before the study, those with BRCA1 mutations faced a 72 percent chance of developing breast cancer by age 80, and the BRCA2 carriers had a 69 percent chance of developing breast cancer by age 80.
— The rate of new breast cancer cases increased rapidly among younger women, but leveled off around ages 30 to 40 for BRCA1 carriers and 40 to 50 for BRCA2 carriers.