Many women diagnosed with breast cancer, especially younger women, are concerned about their ability to have children after treatment. Some breast cancer treatments can cause temporary infertility or make it harder to get pregnant after treatment ends. Other treatments, especially certain chemotherapy regimens, can cause early menopause and infertility.
A meta-analysis suggests that women diagnosed with breast cancer who are treated with a luteinizing hormone-releasing hormone agonist in addition to chemotherapy may be more likely to become pregnant after chemotherapy ends.
The research was presented on Sept. 28, 2015 at the 2015 European Cancer Congress and published online on Sept. 7, 2015 by the Annals of Oncology.
Read the abstract of “Ovarian suppression using luteinizing hormone-releasing hormone agonists during chemotherapy to preserve ovarian function and fertility of breast cancer patients: a meta-analysis of randomized studies."
Luteinizing hormone-releasing hormone agonists are medicines that lower the amount of sex hormones in the body. In women, they stop the ovaries from making estrogen and progesterone. In men, they stop the testicles from making testosterone. Luteinizing hormone-releasing hormone agonists are also called LHRHa, LH-RH agonists, gonadotropin-releasing hormone agonists, and GnRH agonists. Lupron (chemical name: leuprolide), Trelstar (chemical name: triptorelin), and Zoladex (chemical name: goserelin) are all luteinizing hormone-releasing hormone agonists.
A meta-analysis is a study that combines and analyzes the results of many earlier studies. In this case, the results from 1,231 women from 12 studies were analyzed. All the women were premenopausal when diagnosed with breast cancer. All the women were treated with chemotherapy. Half of the women also were treated with a luteinizing hormone-releasing hormone agonist.
When they did their first analysis, the researchers found that women who were treated with both chemotherapy and a luteinizing hormone-releasing hormone agonist were about 64% more likely to have their periods return after chemotherapy was completed compared to women who got chemotherapy alone. In other words, adding a luteinizing hormone-releasing hormone agonist to chemotherapy reduced premature ovarian failure by about two-thirds.
But when they looked more closely at the studies, the researchers found that the studies used different definitions of premature ovarian failure and the results ranged widely from study to study.
So the researchers then analyzed the eight studies that included information on whether a woman’s periods had restarted 1 year after chemotherapy.
The second analysis found that adding a luteinizing hormone-releasing hormone agonist to chemotherapy reduced premature ovarian failure by 45% compared to chemotherapy alone. This analysis found similar results among all the studies.
Adding a luteinizing hormone-releasing hormone agonist to chemotherapy was originally done to preserve ovarian function rather than fertility, so only five of the studies reported on pregnancy rates after breast cancer treatment. In these five studies:
- 33 women who received a luteinizing hormone-releasing hormone agonist and chemotherapy became pregnant after treatment ended
- 19 women who received chemotherapy alone became pregnant after treatment ended
So adding a luteinizing hormone-releasing hormone agonist to chemotherapy increased a woman’s chances of becoming pregnant by about 83%. This increase was similar across the five studies.
"We found that temporary suppression of ovarian function with LHRHa significantly reduces the risk of premature ovarian failure caused by chemotherapy. It also seems to be associated with a higher pregnancy rate in young breast cancer patients,” said Matteo Lambertini, M.D., a medical oncologist at the IRCCS AOU San Martino-IST University Hospital in Genoa, Italy and lead author of the study. "In breast cancer patients, we believe there is now sufficient evidence to suggest that the administration of LHRHa could be considered a potential standard strategy to preserve ovarian function and might also play a role in increasing the likelihood of pregnancy after chemotherapy."
If you’re a premenopausal woman who’s been diagnosed with breast cancer and are concerned about preserving your fertility, you might want to talk to your doctor about this study. It may be possible that you can be given a luteinizing hormone-releasing hormone agonist in addition to chemotherapy to shut down your ovaries and help preserve your fertility.
There also are other options available, including harvesting mature eggs from your ovaries before treatment starts. The most important thing to do is to talk to your doctor about fertility as you’re planning your treatment. You also can ask for a referral to a fertility specialist for counseling before treatment begins.
For more information, visit the Breastcancer.org pages on Fertility and Pregnancy Issues During and After Breast Cancer.