ASCO Annual Meeting
May 30, 2014
Results from a recent phase III clinical trial show that women who took goserelin (Zoladex) with chemotherapy for early-stage, hormone receptor-negative breast cancer were 64% less likely to develop premature ovarian failure, also called early menopause, compared with women who received chemotherapy alone. Ovarian failure causes women to not be able to have children (infertility). It is a common side effect of the standard chemotherapy used for breast cancer treatment. However, a woman’s personal risk of early menopause depends on the type and dose of chemotherapy she receives, as well as her age and a number of other factors.
To try to preserve fertility, the researchers looked at using goserelin, a drug that temporarily shuts down ovarian function. It is thought that this protects the structures inside the ovaries where immature eggs develop, known as follicles, from chemotherapy damage. Medications like goserelin are widely used to control ovulation timing for infertility procedures, such as in vitro fertilization, and as hormonal therapies to treat advanced prostate and breast cancers.
As part of this study, 257 women with early-stage (stages I to IIIA), hormone receptor-negative breast cancer who had not already gone through menopause either received chemotherapy or chemotherapy plus goserelin. Goserelin was given as a monthly injection, starting one week before the first dose of chemotherapy.
Two years after starting chemotherapy, 8% of women who took goserelin experienced ovarian failure compared with 22% of women who only received chemotherapy. During this time, 22 women (21%) who took goserelin became pregnant compared with 12 women (11%) who only received chemotherapy. These pregnancies resulted in 16 women (15%) in the goserelin group delivering at least one baby versus eight women (7%) in the chemotherapy group. Three women in the goserelin group and two in the chemotherapy group were still pregnant when the data were collected. According to the researchers, taking goserelin did not increase the risk of miscarriage or pregnancy termination.
Interestingly, survival rates also improved among women taking goserelin. Women in the goserelin group were 50% more likely to be alive four years after starting chemotherapy compared with those in the chemotherapy group. Although these results establish a role for using drugs like goserelin to preserve ovarian function and fertility during breast cancer treatment, more research is needed to understand any effect these medications may have on survival.
What this means for patients
“Preserving fertility is a common and important concern among younger women diagnosed with cancer, and these findings offer a simple, new option for women with breast cancer, or possibly other cancers,” said lead study author Halle Moore, MD, a staff physician at the Cleveland Clinic in Ohio. “Goserelin appears to be not only highly safe but also effective, as it increased the odds of becoming pregnant and delivering a healthy baby following chemotherapy.”
Questions to ask your doctor
- Could my treatment plan affect my ability to have children?
- Who can help me understand the options for preserving my fertility?
- Can you recommend a fertility specialist I can talk with before treatment begins?
- Will any of the fertility-preservation options affect how well the cancer treatment works?
- How will each option affect my health and the health of my future children?
- What costs are associated with each of my fertility-preservation options? What is covered by my insurance?