According to the results of a study published in Breast Cancer Research and Treatment, the risk of breast cancer among women with a BRCA1 or BRCA2 mutation does not vary by age at first birth.
Inherited mutations in two genes-BRCA1 and BRCA2-have been found to greatly increase the lifetime risk of developing breast and ovarian cancer. Alterations in these genes can be passed down through either the mother’s or the father’s side of the family.
Among women with a BRCA1 or BRCA2 mutation, an important goal of research is to identify treatments, screening tools, and behavioral changes that can reduce the risk of developing breast cancer or improve early detection of cancer.
An early age at first birth has been shown to decrease breast cancer risk among women in the general population. It is uncertain, however, whether age at first birth influences breast cancer risk among women with a BRCA1 or BRCA2 mutation.
To explore the relationship between age at first birth and breast cancer risk in women with a BRCA1 or BRCA2 mutation, researchers conducted a study among 1,816 BRCA1/2 carriers with a history of breast cancer; they were evaluated with an age- and mutation-matched comparison group consisting of 1,816 BRCA1/2 carriers who did not have a history of breast cancer.
Among women who had given birth, age at first birth was similar among women who did and did not have a history of breast cancer.
The researchers conclude that in contrast to what has been observed among women in the general population, a young age at first birth does not appear to reduce the risk of breast cancer in women with a BRCA1 or BRCA2 mutation. Nevertheless, the researchers note that BRCA1/2 carriers who are considering a prophylactic oophorectomy (preventive removal of the ovaries) should try to complete their childbearing before the age of 40, when risk of ovarian cancer begins to rise.
Reference: Kotsopoulos J, Lubinski J, Lynch HT et al. Age at first birth and the risk of breast cancer in BRCA1 and BRCA2 mutation carriers. Breast Cancer Research and Treatment [early online publication]. January 24, 2007.