Breast Cancer After Childbirth and Survival in Women With BRCA Mutation
Women with a BRCA1 or BRCA2 mutation have a greater risk of being diagnosed with breast cancer at a young age than women without one of these mutations. A study in JAMA Network Open suggests that women with a BRCA mutation diagnosed with breast cancer before age 45 and within 10 years of giving birth may be more likely to die younger than those who never gave birth or were diagnosed after 10 years of giving birth.
Key takeaways
Women with a BRCA1 or BRCA2 mutation who were diagnosed with breast cancer and had given birth in the last 10 years were 56% more likely to die from any cause over the study period (about 10 years) than women who didn’t have a child or women who were diagnosed with breast cancer more than 10 years after giving birth.
Overall, the risk of death was the highest for women diagnosed with estrogen receptor-positive breast cancer within five years of giving birth and for women diagnosed with estrogen receptor-negative breast cancer five to 10 years after giving birth.
For women with a BRCA1 mutation, being diagnosed with breast cancer within five to 10 years after giving birth carried the greatest risk of death.
What the results mean for you
If you know you have a BRCA1 or BRCA2 mutation and were diagnosed with breast cancer within 10 years after having a child, it’s important to tell your healthcare team how long ago you gave birth. This information helps you and your doctor develop a treatment plan that takes into account the aggressiveness of the cancer as well as your personal preferences and other health history.
Although this study looked specifically at women with a BRCA1 or BRCA2 mutation, the results echo the findings of other studies, suggesting that breast cancers diagnosed after giving birth are more aggressive, more likely to come back, or spread to areas of the body outside the breast, such as the bones or liver.
About the study
Women with a BRCA1 or BRCA2 mutation have up to about a 72% risk of being diagnosed with breast cancer in their lifetimes. The researchers wanted to know if the amount of time between giving birth and a breast cancer diagnosis was linked to a higher risk of dying from any cause.
They analyzed the health records of 903 women with a BRCA1 or BRCA2 mutation who were diagnosed with stage I to stage III breast cancer at age 45 or younger between 1950 and 2021 in the United Kingdom. The women — who were an average age of 35 years at the start of the study — were followed for about 11 years.
Overall:
56% of the women had a BRCA1 mutation
44% had a BRCA2 mutation
25% of the women had never given birth
46% of the women were diagnosed with breast cancer within 10 years after giving birth
29% of the women were diagnosed with breast cancer more than 10 years after giving birth
Detailed results
Compared to women who had not given birth:
Women who were diagnosed five to 10 years after giving birth had 1.7 times the risk of death during the study. This risk remained after the researchers accounted for estrogen receptor status, mutation type, and age at diagnosis. There was no increase in risk if women were diagnosed less than five years after giving birth.
Women with a BRCA1 mutation diagnosed with breast cancer within 10 years of giving birth had twice the risk of death.
Women with a BRCA2 mutation who were diagnosed with breast cancer within 10 years of giving birth were at no greater risk of death.
Women who were diagnosed with breast cancer more than 10 years after giving birth were no more likely to die during the study.
The researchers said the differences in death risk in women with BRCA1 versus BRCA2 mutations suggests that the overall increase in mortality seen in the study was mainly in women with a BRCA1 mutation. It could also have been that the study didn’t include enough women with a BRCA2 mutation.
Among women diagnosed with estrogen receptor-positive breast cancer, BRCA2 was the most common mutation; about 60% to 75% of the women in each childbearing group had that mutation. Among women with estrogen receptor-negative breast cancer, BRCA1 was the most common mutation; about 75% to 87% of the women in each childbearing group had that mutation.
Women diagnosed with estrogen receptor-positive breast cancer within 10 years of giving birth had more than twice the risk of overall mortality.
Women diagnosed with estrogen receptor-positive breast cancer within five years of giving birth had the highest increased risk of overall mortality.
Women diagnosed with estrogen receptor-negative breast cancer five to 10 years after giving birth had more than three times the risk of overall mortality.
Zhang Z, Ye S, Bernhardt SM, et al. Postpartum Breast Cancer and Survival in Women With Germline BRCA Pathogenic Variants. JAMA Netw Open. 2024;7(4):e247421.
— Last updated on December 27, 2024 at 6:59 PM