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 premenopausal women diagnosed with early-stage breast cancer who are treated with gonadotropin-releasing hormone analog during chemotherapy are more likely to have their periods return after treatment ends and may be more likely to have children after breast cancer treatment.
The research was presented on Dec. 7, 2017 at the 2017 San Antonio Breast Cancer Symposium. Read the abstract of “Pooled analysis of five randomized trials investigating temporary ovarian suppression with gonadotropin-releasing hormone analogs during chemotherapy as a strategy to preserve ovarian function and fertility in premenopausal early breast cancer patients.”
“Fertility preservation and pregnancy-related issues are a high priority or of concern for the younger women with breast cancer,” said Dr. Matteo Lambertini, medical oncologist at the Institute Jules Bordet in Brussels, who presented the research. “Approximately half of the young breast cancer patients are concerned about the possible risk of infertility as a consequence of cancer treatment. And approximately the same percentage of women…will desire to have a pregnancy after the end of treatment.”
Gonadotropin-releasing hormone analogs 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. Lupron (chemical name: leuprolide), Trelstar (chemical name: triptorelin), and Zoladex (chemical name: goserelin) are all GnRHas.
A meta-analysis is a study that combines and analyzes the results of many earlier studies. In this case, the results from 873 women from five randomized studies were analyzed. All the women were premenopausal when diagnosed with early-stage breast cancer. All the women were treated with chemotherapy:
- 437 women were treated with chemotherapy alone
- 436 women were treated with chemotherapy and a GnRHa
Temporarily suppressing the ovaries with a GnRHa during chemotherapy was mainly developed as a strategy to reduce the risk of treatment-induced premature menopause, Lambertini explained. So most of the studies that looked at this strategy had very short follow-up times and didn’t report on how many pregnancies there were after treatment.
“Temporary ovarian suppression by administering GnRHa during chemotherapy is a medical intervention with the potential to preserve ovarian function and fertility in premenopausal breast cancer patients; however, to date, the role of this option remains controversial and it is still considered an experimental technique by the American Society of Clinical Oncology (ASCO) and the European Society for Medical Oncology (ESMO),” Lambertini explained. “We wanted to provide more conclusive clinical evidence.”
The meta-analysis found that 2 years after treatment, early menopause caused by chemotherapy happened in:
- about 31% of women treated with chemotherapy alone
- about 14% of women treated with chemotherapy and a GnRHa
So the women who had temporary ovarian suppression with a GnRHa were half as likely to develop early menopause. This difference was statistically significant, which means that it was likely due to the difference in treatment and not just because of chance.
Pregnancy results were:
- 37 (10.3%) women treated with chemotherapy and a GnRHa had at least one post-treatment pregnancy
- 20 (5.5%) women treated with chemotherapy alone had at least one post-treatment pregnancy
This difference also was significant.
“This means that less than 10% of the patients included in these randomized control trials had a pregnancy after the end of treatment, which is a low percentage overall,” Lambertini explained. “But it’s important to note that there was a significantly higher number of patients who were able to have a pregnancy after the end of treatment if they received [GnRHa] during chemotherapy.”
The 57 pregnancies resulted in 50 live births. Because the study was a meta-analysis, the researchers didn’t know how many women in the studies wanted to become pregnant.
After 5 years of follow-up, there was no difference in disease-free survival or overall survival between the two treatment groups. Lambertini said these results suggest that giving a GnRHa with chemotherapy can be considered safe.
Disease-free survival is how long a person lives without the cancer growing. Overall survival is how long a person lives, whether or not the cancer grows.
“This study provides solid evidence on this specific topic,” Lambertini said. “We believe that the results of our study would serve as the reference evidence for updating the international ASCO and ESMO guidelines on the use of this strategy.”
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 meta-analysis. It may be possible that you can be given a gonadotropin-releasing hormone analog in addition to chemotherapy to shut down your ovaries and possibly 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.
Listen to a podcast with Dr. Lambertini about this study.