Fertility Drugs not tied to Breast Cancer Risk
Fertility drug treatments can take a toll on one's body. In a new study, researchers examined the effects of fertility drugs, clomiphene citrate, prescribed with the brand name, Clomid and gonadotropins. The team found that the fertility drugs did not increase a woman's risk of breast cancer.
"We wanted to evaluate the long-term relationship of fertility medications and breast cancer risk after controlling for other factors that have been shown to be correlated with both breast cancer risk and use of those drugs," said Louise A. Brinton, Ph.D., M.P.H., chief of the Hormonal and Reproductive Epidemiology Branch at the National Cancer Institute (NCI) in Bethesda, MD. "Overall, our data show that use of fertility drugs does not increase breast cancer risk in this population of women, which is reassuring."
Brinton and her team reviewed data from more than 12,000 women who were examined for infertility between 1965 and 1988. 9,892 of the female participants were used in this study and the patients came from five different parts of the United States. The data included infertility evaluations and treatments. The women were followed until 2010 and 749 of them had developed breast cancer. Out of the cancer patients, the researchers had medical documentation for 696 of them. 536 had invasive breast cancers.
The researchers found that for women who took 12 or more cycles of clomiphene citrate, they had a 1.5 times increased risk of developing invasive breast cancer in comparison to women who never took fertility drugs. The team also found that the risk of invasive breast cancer for women who were still infertile after taking clomiphene citrate and gonadotropins was two times greater than women who never took the drugs.
"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 according to the press release. "Nevertheless, these findings stress the importance of continued monitoring of women who are exposed to fertility drugs."
The study examined particularly high levels of fertility drugs. Currently, clomiphene citrate is limited to three to six cycles. The study was published in Cancer Epidemiology, Biomarkers & Prevention.