According to recent statistics, a woman has a 1 in 8 lifetime chance of being diagnosed with breast cancer. This disease is the leading cause of cancer death for women. Many fertility and reproductive factors contribute to risk, such as nulligravidity (never having a child), early menopause, late menopause, and hormone use.
Infertility affects around 10% of all couples. Infertile women are likely to be diagnosed with menstrual abnormalities. However, infertility is often managed using hormone therapy, which can have a direct negative effect on the breast tissue. Incidentally, elevated estradiol levels have an indirect effect on the breasts. Because the potential increased risk for breast cancer is a concern, many infertility therapies are being studied.
A Research Report
Infertility can be treated using assistive reproductive technologies (ARTs), such as in vitro fertilization (IVF) and intrauterine insemination (IUI). A recent study was conducted that include nulliparous (never had a child) women and parous (had children before) women. These women were between ages 20 and 44 years, and all had been evaluated for infertility. Of these 21,000 women, 7,381 had IVF treatment. The researchers found that the risk for breast cancer was NOT increased for infertile women who underwent IVF therapy.
In the study, controlled factors were the need for IVF treatment, single vs. multiple birth, age at first delivery, and socioeconomic status. The factors seen to be associated with an increased risk for breast cancer was older age at first delivery. However, multiple births was associated with a decreased risk for breast cancer. The different age groups were analyzed for variances. The risk for breast cancer was higher for infertility women who began treatment at age 24 years or younger.
The Role of Hormones
It is established that older age at first delivery and nulliparity are linked to more cases of breast cancer. Hormone use has also been identified as a risk factor for breast cancer. Infertility women who have IVF cycles are already at higher risk than the general population.
So, does using hormones for IVF further increase this known risk? Most studies have shown no increased risk for breast cancer for women who have undergone IVF treatment. However, some studies only involve a low number of participants. Other studies do not properly control for all risks factors, making the conclusions questionable. The main factor involved is an inherited genetic risk, which is rarely considered in these studies.
With infertility treatment, hormone use is only short term (about 10 days), which does not have a significant effect on the induction and growth of breast cancer. The current information on this association is reassuring. Studies show that there is no real danger for increased breast cancer simply from using hormone therapy during IVF treatment. Exposure to progestin and estrogen after menopause is linked to an increased risk for breast cancer for women who are 50-70 years of age.
Recommendations for Women undergoing Fertility Treatment
The standards and recommendations for women undergoing fertility treatment is the same for women who have breast cancer risk factors. There is no evidence that IVF will increase your risk for breast cancer, and it is not contraindicated unless the woman has active breast cancer. This applies even to women who have a family history of the disease or who carry the BRCA (breast cancer) gene.
Any woman who is trying to conceive should follow the regular guidelines for health maintenance, and make sure routine screenings and Pap smears are up to date. For women without significant risk factors, a routine mammogram is recommended at age 40.