Cleveland Clinic Cancer Care
June 2, 2014
Chemotherapy for young women with breast cancer has a serious permanent side effect: infertility due to irreversible damage to the ovaries.
But a new study shows that a hormone-blocking drug taken during chemotherapy can help young female breast cancer patients avoid ovary damage and go on to have children later.
Researchers presented results of the study, called the Prevention of Early Menopause Study (POEMS), on Friday, May 30 at the 50th annual meeting of the American Society for Clinical Oncology (ASCO).
In the study, patients who received a drug called goserelin during chemotherapy for breast cancer experienced an 8 percent ovarian failure rate compared to 22 percent for the control group two years after treatment.
Goserelin is a synthetic version of a naturally occurring hormone. It works by putting the ovaries in a state of rest and prevents their normal cycle. The resting state makes the ovaries less vulnerable to the toxic effects of chemotherapy.
Ovarian failure is when your ovaries no longer work normally. They don't produce normal amounts of the hormone estrogen or release eggs regularly. Infertility is a common result.
Fifteen percent of women in the study who received goserelin were able to get pregnant and give birth after their cancer treatment.
Just 7 percent of the women in the control group, which did not receive goserelin, were able to get pregnant and give birth during the same timeframe.
"The results found that our intervention, which was giving a shot under the skin once a month before treatment, was able to improve measures of ovarian function," says Halle C.F. Moore, MD, a breast cancer oncologist at Cleveland Clinic.
Dr. Moore was the study's lead investigator.
"In addition, we saw more pregnancies and more children being born in the group that received the intervention," Dr. Moore says.
POEMS is the first study to provide strong evidence that fertility prospects can improve after treatment with ovarian suppression during chemotherapy, Dr. Moore says.
"Preserving ovarian function is a vital survivorship issue for young breast cancer patients. Now we can use an intervention that can improve fertility and help avoid other unwanted effects of early menopause," Dr. Moore says.
Ovarian failure, or early menopause, is a common long-term side effect of chemotherapy.
Cancer patients with premature ovarian failure have an increased risk of developing long-term health problems. These problems include osteoporosis, infertility and possibly cardiovascular disease.
Better survival rates too
POEMS enrolled 218 premenopausal women worldwide who had early stage hormone-receptor-negative breast cancer from 2004 to 2011.
Researchers randomly assigned patients randomly to two groups. One group received standard chemotherapy. The other received standard treatment as well as goserelin every four weeks.
Surprisingly, in addition to preserving ovarian function, the patients who received goserelin experienced better disease-free survival and overall survival rates than the group that did not.
"We found that the women who received the goserelin actually had fewer recurrences of their breast cancer," Dr. Moore says. "They appeared to do better in overall survival as well."
POEMS is the largest reported randomized study addressing the role of an LHRH agonist during chemotherapy for ovarian protection in women with hormone receptor-negative breast cancer.
Southwest Oncology Group (SWOG) was the coordinator of the study. The cancer research cooperative group designs and conducts multidisciplinary clinical trials.