Double Agent Tamoxifen a Fertility Drug

Tamoxifen doing double duty with breast cancer

/ Author:  / Reviewed by: Joseph V. Madia, MD

(RxWiki News) Turning events that seem like an ending into a new beginning is one of the secrets to achieving a happy life. Young women with breast cancer can now do this.

Diagnosing breast cancer doesn't have to be an ending to your family plans. It can be a beginning with the fantastic advances fertility scientists are making. 

Researchers from Cornell University achieved the first in-vitro fertilization pregnancy using the cancer drug tamoxifen to stimulate ovaries in a breast cancer patient.

"If facing chemotherapy, ask your OB/GYN about egg and embryo freezing."

Lead researcher Kutluk Oktay, M.D., assistant professor of Reproductive Medicine and Obstetrics and Gynecology at the Center for Reproductive Medicine and Infertility, Weill Medical College of Cornell University, describes the emergence of the study arose from a desire to safely preserve fertility in breast cancer patients.

Women who are still in their reproductive years account for 15 percent of all breast cancer patients.

The doctor's optimism is apparent. Even the hope of preserving fertility gives these women facing chemotherapy a brighter outlook for the future. Connecting to a future, better life is key here and it makes them believe that breast cancer doesn't have to terminate family plans.

Dr. Oktay says young women can try IVF without ovary stimulation, but only one embryo is usually retrieved without stimulation. The type of chemotherapy required in most breast cancer cases causes ovarian failure in 80 percent of women.

Therefore, Dr. Oktay and team wanted to safely stimulate the ovaries in breast cancer patients prior to chemotherapy Retrieving as many eggs as possible to freeze increases the chances of having a viable pregnancy after chemotherapy.

The use of tamoxifen as an ovary stimulant could not have been more obvious, according to Dr. Oktay. They hypothesized that tamoxifen would shield breast cancer cells from estrogen as well as stimulate the ovaries to produce more eggs.

A group of five breast cancer patients who already had undergone nine cycles of natural cycle IVF was used as a control group for the 12 study patients. The 12 participants were given 40-60 mg tamoxifen for seven days, beginning on day two or three of their menstrual cycle. The participants produced a greater number of eggs than the women not using ovarian stimulation. (1.6 versus 0.7). All patients taking tamoxifen generated embryos compared with three out of five controls. After 15 months, none of the study participants has had their cancer return.

Dr. Oktay recognizes the study's limitations with the size of both groups, but plans a larger study that will include different doses of other drugs in addition to tamoxifen. He also urges all oncologists and ob/gyn's to anticipate the effect of chemotherapy on young women and refer them to an IVF center quickly after their cancer diagnosis so options for a future family are still in place.

This study is published in the European reproductive medicine journal Human Reproduction.

Reviewed by: 
Review Date: 
August 5, 2011
Last Updated:
August 9, 2011