Hormonal Infertility Treatment May Increase Breast Cancer Risk

Hormonal infertility treatments have been found to increase the amount of dense breast tissue, potentially increasing the risk of breast cancer, according to a study published in Breast Cancer Research.

The study included 43,413 women aged between 40 to 69 years who had mammograms between 2010 and 2013 as a part of the Karolinska Mammography project.

Participants also filled out a questionnaire that included information about age, height, weight, smoking status, alcohol consumption, history of infertility, and any family history of breast cancer.

There were 8963 participants who had fertility problems. Of those participants, 1576 had controlled ovarian stimulation (COS). Additionally, 1429 of those participants had hormonal stimulation other than COS, while 5948 were not treated.

Researchers compared the breast density of infertile and fertile participants. Then, the breast density between infertile participants who received hormonal treatment against those who did not.

It was found that infertile participants had higher breast density than participants who were fertile.

Infertile participants who had underwent COS had a higher breast density than infertile participants who did not receive hormone treatment.

"The results from our study indicate that infertile women, especially those who undergo COS, might represent a group with an increased breast cancer risk,” Frida Lundberg, lead author of the study, stated in a press release. “While we believe it is important to continue monitoring these women, the observed difference in breast tissue volume is relatively small and has only been linked to a modest increase in breast cancer risk in previous studies."

Researchers said that though a direct connection could not be established, it is important to monitor women undergoing COS.