BRCA1 and cancer risks for women and people assigned female at birth

Women, and people assigned female at birth, who have a BRCA1 gene variant have a higher risk of developing breast, ovarian and pancreatic cancer. This page explains more about these risks. It should be read with our general information about BRCA.

If you have a BRCA1 variant, it is important to talk to your genetics specialist about your cancer risk. They will explain the numbers below and give you more detailed information based on:

• your age
• the most recent research about the type of BRCA1 gene variant you have
• your family history of cancer
• factors in your lifestyle or medical history.

It can be difficult to understand risk statistics and what they mean for you. You may find it helpful to print this page and take it with you to your genetics specialist.

Lifetime risk of breast cancer

Of 100 women in the general population, 14 or 15 of them will develop breast cancer before the age of 80. This also means 85 or 86 of them will not develop breast cancer.

The risk is higher if you have a BRCA1 variant. Of 100 women with a BRCA1 variant, 65 to 79 of them will develop breast cancer before the age of 80. This also means 21 to 35 of them will not develop breast cancer.

If you have a type of BRCA1 variant called R1699Q, your risk of breast cancer is higher than the general population but less than with other type of BRCA1 variant. Of 100 women with a BRCA1 R1699Q variant, 13 to 32 of them will develop breast cancer before the age of 70. This also means 68 to 87 of them will not develop breast cancer. 

Lifetime risk of ovarian cancer

Of 100 women in the general population, 2 of them will develop ovarian cancer before the age of 80. This also means 98 of them will not develop ovarian cancer.

The risk is higher if you have a BRCA1 variant. Of 100 women with a BRCA1 variant, 36 to 53 of them will develop ovarian cancer before the age of 80. This also means 47 to 64 of them will not develop ovarian cancer.

If you have a type of BRCA1 variant called R1699Q, your risk of ovarian cancer is higher than the general population but less than with other types of BRCA1 variant. 

Of 100 women with a BRCA1 R1699Q variant, 3 to 25 of them will develop ovarian cancer before the age of 70. This also means 75 to 97 of them will not develop ovarian cancer.

Lifetime risk of pancreatic cancer

Of 100 people in the general population, 1 or 2 of them will develop pancreatic cancer before the age of 80. This also means 98 or 99 of them will not develop pancreatic cancer.

The risk is slightly higher if you have a BRCA1 variant. Of 100 women with a BRCA1 variant, between 2 and 4 of them will develop pancreatic cancer before the age of 80. This also means 96 to 98 of them will not develop pancreatic cancer.