Risks of Ovarian Stimulation

June 5, 2009

One of the issues for women having difficulties with reproduction is the cancer-related risks of ovarian stimulation. Are risks for ovarian or breast cancer increased if a woman takes drugs to improve fertility?

One of the issues for women having difficulties with reproduction is the cancer-related risks of ovarian stimulation. Are risks for ovarian or breast cancer increased if a woman takes drugs to improve fertility? A study out of the London School of Hygiene and Tropical Medicine finds reassuring news for women facing this question.

In their study, Dos Santos Silva and colleagues followed over 7,000 women having ovulatory disorders over a 20-year period. Of these women 43% received ovarian-stimulation drugs, providing a very good sample for this case-control study. Compared to the general population, they reported that women with ovulatory problems had a a 2-fold increased risk of uterine cancer (statistically significant) and a 13% increased risk of breast cancer (not statistically significant). However, comparing within the cohort, those who had undertaken ovarian stimulation were not at an increased risk of any cancer type—including those of the breast and gynecologic tract.

These data support prior work in the field. For example, Brinton, et al. from the Natonal Cancer Institute evaluated the risk of both breast and of ovarian cancer associated with the use of ovarian-stimulatory drugs, including clomiphene and gonadotropins, and also did not find a link between ovarian stimulation and ovarian cancer. These results should prove reassuring to women undergoing ovarian stimulation for infertility and provides much needed hope that the labors to have a child will not cost the mother her life, as a direct result of cancer. Clearly, the risks associated with carcinogenesis are multifactorial, and not easily explained by the use of medications. What the interplay is between biology, environment, and exposure remains an area of active investigation.

At the end of this month I will be travelling to Orlando, FL for the American Society of Clinical Oncology Annual Meeting. I will plan to bring back some highlights from this premiere meeting of oncology specialists, especially as it relates to women's cancers!

For further information: Dos Santos Silva I, Wark PA, McCormack VA, Mayer D, Overton C, Little V, Nieto J, Hardiman P, Davies M, Maclean AB.Ovulation-stimulation drugs and cancer risks: a long-term follow-up of a British cohort. Br J Cancer. 2009 May 12. [Epub ahead of print]