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 study suggests women diagnosed with early-stage breast cancer who are treated with Trelstar (chemical name: triptorelin) in addition to chemotherapy might find it easier to get pregnant after chemotherapy ends, but the results weren’t definitive.
The research was presented on Sept. 4, 2014 at the 2014 ASCO Breast Symposium. Read the abstract of “Long-term outcome results of the phase III PROMISE-GIM6 study evaluating the role of LHRH analog (LHRHa) during chemotherapy (CT) as a strategy to reduce ovarian failure in early breast cancer (BC) patients.”
Trelstar is a luteinizing hormone-releasing hormone. Trelstar blocks hormones that tell the ovaries to get ready for ovulation. Ovulation happens when a mature egg is released from the ovary, ready to be fertilized. If the ovulation hormones are blocked, no ovulation occurs. So Trelstar causes the ovaries to temporarily shut down. By doing this while a woman is being treated with chemotherapy, the goal is to help protect the eggs from the chemotherapy medicine.
In this study, 281 premenopausal women diagnosed with early-stage breast cancer (80% of the cancers were hormone-receptor-positive) who were going to receive chemotherapy to treat breast cancer were randomly assigned to be treated with either:
- chemotherapy alone
- chemotherapy plus Trelstar
Results from this study published previously showed that women who got Trelstar along with chemotherapy were 72% less likely to have ovarian failure after chemotherapy. The researchers then wanted to know if Trelstar’s ability to stop ovarian failure would translate into more pregnancies.
The analysis presented at ASCO Breast was designed to provide long-term information on Trelstar’s ability to preserve fertility and see how many women got pregnant after being treated with chemotherapy. This analysis included 246 women who were followed for more than 7 years.
The researchers found:
- 3 women who were treated with only chemotherapy got pregnant and all three had their babies
- 8 women who were treated with chemotherapy plus Trelstar got pregnant, which resulted in five births (two pregnancies ended in miscarriage and one was aborted)
Menstruation started again in:
- 72.6% of women who got chemotherapy plus Trelstar
- 64% of women who got chemotherapy alone
The higher rates of pregnancy and menstruation restarting weren’t statistically significant, which means they could have happened by chance and may not have been due to the addition of Trelstar.
The researchers also found that adding Trelstar to chemotherapy didn’t affect survival rates or the chemotherapy’s ability to fight the cancer.
“The use of [Trelstar] showed a trend towards an increased probability for becoming pregnant and a trend towards an increased probability for menstrual resumption at longer follow-up, although neither finding was significant," said Matteo Lambertini, M.D., of Azienda Ospedaliera Universitaria San Martino in Genova, Italy and the study’s lead author. “The lack of difference in 5-year disease-free survival between the two arms was reassuring regarding the safety of the procedure.”
While the results of this study aren’t a slam dunk, they are encouraging and echo results from a study presented in May 2014 at the American Society of Clinical Oncology Annual Meeting showing that women diagnosed with hormone-receptor-negative, early-stage breast cancer who were treated with Zoladex (chemical name: goserelin) in addition to chemotherapy before surgery were much less likely to be infertile after chemotherapy ended.
If you’re a premenopausal woman who’s been diagnosed with early-stage breast cancer and are concerned about preserving your fertility, you might want to talk to your doctor about this study and the study on Zoladex. It may be possible that you can be given medicine in addition to your 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.