Study: Hormone Drug Preserves Fertility in Breast Cancer Patients Getting Chemotherapy

Breast cancer patients taking part in an international study were less likely to go through early menopause and more likely to become pregnant and give birth if they took the drug Zoladex (goserelin) during chemotherapy. The women in the study had operable hormone-receptor-negative breast cancer. The study was published in the March 5, 2015 issue of The New England Journal of Medicine.

Loss of fertility is often a side effect of chemotherapy, which can create treatment challenges for young women with breast cancer. If they choose to have chemotherapy after breast cancer surgery, it can reduce the chances that cancer will come back, but it also increases the chances of ovarian failure – which causes early menopause and infertility. Goserelin works by blocking the normal cycle of the ovaries, making them less vulnerable to damage by chemotherapy.

The study involved 218 pre-menopausal women ages 18 to 49 with hormone-receptor-negative breast cancer who planned to have chemotherapy after surgery. Half the women received goserelin and chemotherapy, and the other half received only chemotherapy. After 2 years, researchers evaluated 135 women from the original group. The others could not be located, had missing information, or had died.

Of the 135, 8% of the women in the goserelin group experienced ovarian failure compared to 22% in the chemo-only group. Twenty-one percent of the women in the goserelin group had at least one pregnancy compared with 11% of the chemo-only group. In all, 18 babies were born to women in the goserelin group compared to 12 babies born to women in the chemo-alone group.

The study also showed that goserelin did not interfere with the women’s breast cancer treatment. In fact, the women in the goserelin group were slightly less likely to die or to have their cancer come back than the women in the chemo-only group.

Goserelin is implanted under the skin of the abdomen with a needle. It can cause the same kinds of side effects that are experienced by women going through menopause, including hot flashes, mood changes, and sleep problems. More serious side effects are less common but possible. They include difficulty breathing or swallowing, dizziness or fainting, and bone pain.

Because cancer treatment can affect the ability to have children, women – and men – getting treatment for any cancer and who might still want to have children should talk to their medical providers about the fertility risks of treatment.

The American Cancer Society medical and editorial content team

Our team is made up of doctors and oncology certified nurses with deep knowledge of cancer care as well as journalists, editors, and translators with extensive experience in medical writing.

Goserelin for Ovarian Protection during Breast-Cancer Adjuvant Chemotherapy. Published in the March 5, 2015 issue of The New England Journal of Medicine. First author Halle C.F. Moore, MD, the Cleveland Clinic Foundation, Cleveland.

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