Since the 1990s, researchers have published conflicting results about the connection between cancer risk and fertility drugs. As a result, there has been a lingering concern among women that using fertility drugs may increase their risk for later developing hormone receptor positive cancers. Hormone receptor positive tumors consist of cells that express receptors for certain hormones such as estrogen or progesterone, but are most commonly known as estrogen receptor tumors. These types of tumors depend on the presence of estrogen in order to grow and spread throughout the body, making the risk for gynecologic cancers cause for concern in some women undergoing IVF treatment.
Fertility drugs have come under scrutiny because they stimulate hyper-ovulation, meaning they cause a woman’s body to produce more eggs. They have been linked to certain gynecologic cancers, such as breast and ovarian cancer. One reason research published in the 1990s may have suggested a link between fertility drugs and cancer risk, is due to the drugs that were being prescribed 20 years ago. Researchers have also blamed the mixed nature of the findings on the studies’ relatively short length, or on including women who have not given birth as they are known to have an increased risk of some cancers.
New research, however, suggests that using fertility drugs does not have an impact on your risk for developing ovarian cancer down the line. Lead author of the study and clinical fellow in the Division of Reproductive Endocrinology at the Mayo Clinic in Rochester, Minnesota, Dr. Albert Asante and his colleagues gathered medical information on 1900 women from an ongoing ovarian cancer study at the Mayo Clinic. The researchers compared 1,028 women with ovarian cancer to 872 women of similar age who did not have cancer. As reported in Fertility and Sterility, approximately 24 percent of the women who did not have ovarian cancer reported having used fertility drugs, while roughly 17 percent of women who had ovarian cancer had used fertility drugs.
The researchers took into account factors that can influence the risk for ovarian cancer, such as age and use of the birth control pill, and found no difference in cancer rates between the groups. Dr. Asante looked specifically at whether women in the study who reported being infertile- whether or not they had taken fertility drugs – had a greater chance of developing ovarian cancer, and found no added risk. He said one explanation for the result is that most of the women in his study had infertility issues, but eventually became pregnant. According to Dr. Albert Asante, “One important message [from this study] is women who need to use fertility drugs to get pregnant should not worry about using these fertility drugs.”