Researchers Find Fertility Drug Clomid Doesn't Increase Risk Of Breast Cancer

In a 30-year follow-up study, researchers at the National Cancer Institute have found that women using the fertility drug Clomid do not have a higher risk of breast cancer compared to women who are not on the drug. The study was published in the journal Cancer Epidemiology, Biomarkers, and Prevention. Clomid stimulates the production of eggs in women.                                                                                                                          

Louise Brinton, who led the study, said the data is good news for women. “Overall, our data show that use of fertility drugs does not increase breast cancer risk in this population of women, which is reassuring,” said Brinton.

The data comes after a 2009 study completed by another research team, which also concluded that Clomid did not increase rates of ovarian cancer in women, NBC News says. The study has faced some difficulties, especially considering women that are already infertile are at a higher risk for developing cancer. Because of this, it has been difficult to determine if the drugs actually raise the risk of cancer.   

Brinton says that any increased risk of developing cancer, observed in the 9,800 women studied in the research project, was possibly due to infertility, and not due to medications that those women took. “The observed increase in risk for these small subsets of women may be related to persistent infertility rather than an effect of the medications,” said Brinton. “Nevertheless, these findings stress the importance of continued monitoring of women who are exposed to fertility drugs. Given the high doses of drugs received by our study participants and the lack of large increases in breast cancer risk many years after exposure, women previously exposed to such drugs should be reassured by these findings.”

Doctors prescribing Clomid now limit the prescription to three to six cycles, far lowerdoses than prescribed in the past.