Thinking about cancer or dealing with cancer risk can be scary or overwhelming, but we believe that receiving information and resources is comforting, empowering, and lifesaving.
"Cancer previvors" are individuals who are survivors of a predisposition to cancer but who haven’t had the disease. This group includes people who carry a hereditary mutation, a family history of cancer, or some other predisposing factor.
In women with a BRCA mutation who have never had a diagnosis of cancer, the lifetime risk for breast cancer is very high. Experts don't agree on the exact risk but estimates range from 55% - 85% lifetime risk for breast cancer for women with a mutation in either gene.
Different research involving many families with BRCA mutations showed a lower breast cancer risk in women with BRCA mutations: 65% by age 70 for women with a BRCA1 mutation and 45% by age 70 for women with a BRCA2 mutation. Another study combined multiple studies to determine an average risk for breast cancer. This "meta-analysis" determined the average lifetime risk to be 64% in BRCA 1 mutation carriers and 56% in BRCA 2 mutation carriers.
Several factors including lifestyle (diet, weight, and exercise), reproductive choices (number of pregnancies and age at the time of pregnancies), exposure to certain viruses or chemicals, and other genes may account for the differences in risk among people with the same mutation.
Women with mutations in PTEN, CDH1, TP53, or STK11 have about a 50% lifetime risk for breast cancer (although some studies have found the risks to be higher). Women with mutations in PALB2, CHEK2, and ATM also have increased risk of breast cancer, but the lifetime risk for women with these mutations is still an active area of research. NBN and NF1 mutations have been associated with early onset breast cancer, but the exact risk is not known.
Families with a strong family history of breast cancer but no identified mutation in BRCA or other genes associated with cancer risk may still have increased risk for cancer. Experts estimate the women in these families to have a lifetime risk for breast cancer of about 25%. It is important for anyone with breast cancer in their family to speak with a genetics expert to better understand their risk for cancer.
If you are a previvor, understanding your risk to make medical decisions can be confusing and you may want additional guidance or support. FORCE's Peer Navigation Program provides expert reviewed resources and 1:1 personalized peer support by specially trained volunteers who have experienced the very challenges you face.