According to the results of a study conducted in Denmark and published in the British Medical Journal, use of fertility drugs does not increase the risk of ovarian cancer.
The question of whether fertility drugs increase the risk of ovarian cancer has long been debated, and previous studies have reported mixed results. Some researchers have hypothesized that repeated, uninterrupted ovulation may contribute to the development of ovarian cancer; if this is true, it’s possible that fertility drugs could increase ovarian cancer risk by increasing ovulation. It’s also possible that some fertility drugs could have a direct carcinogenic effect on the ovary.
To evaluate the relationship between fertility drugs and risk of ovarian cancer, researchers in Denmark conducted a study among more than 54,000 women who were referred to fertility clinics between 1963 and 1998. The researchers compared the risk of ovarian cancer among the women who used fertility drugs to the risk among women who did not use fertility drugs.
The types of fertility drugs that were evaluated were gonadotropins (follicle stimulating hormone and human menopausal gonadotropins), clomifene citrate, human chorionic gonadotropins, and gonadotropin releasing hormone. Clomifene was the most commonly used drug.
After a median of 16 years of follow-up, 156 women had developed ovarian cancer. Overall, the risk of ovarian cancer was similar among women who had and had not used fertility drugs.
The researchers also analyzed the effects of fertility drugs on specific types of ovarian cancer (serous, endometrioid, mucinous, clear cell, and other). The results suggested that clomifene may increase the risk of serous cancers.
The researchers concluded that “No convincing association was found between use of fertility drugs and risk of ovarian cancer.” They will continue to follow the study participants, however, because many of the women have not yet reached the peak ages for ovarian cancer.
Reference: Jensen A, Sharif H, Frederiksen K, Krüger Kjaer S. Use of fertility drugs and risk of ovarian cancer: Danish population based cohort study. British Medical Journal [early online publication]. February 5, 2009.