SOURCES: George Raptis, M.D., associate chief, hematology/oncology, North Shore University Hospital, Manhasset, N.Y. and Long Island Jewish Medical Center, New Hyde Park, N.Y.; Stephanie Bernik, M.D., chief, surgical oncology, Lenox Hill Hospital, New York City; Loyola University Health System, news release, March 4, 2015
WEDNESDAY, March 4, 2015 (HealthDay News) -- Breast cancer chemotherapy can trigger an unfortunate side effect for some patients -- early menopause.
But a new study suggests that adding the drug goserelin to chemotherapy cuts the odds of that happening in women with certain early-stage breast cancers.
"These findings provide hope for young women with breast cancer who would like to prevent early menopause or still have children," senior study author Dr. Kathy Albain, medical oncologist and director of the Breast Cancer Clinical Research Program at Loyola University, said in a university news release.
The study was funded by the U.S. National Cancer Institite and was published March 4 in the New England Journal of Medicine.
According to Albain, "some of the most distressing side effects of chemotherapy in young women with breast cancer are early and sudden onset of menopause and infertility."
Another expert in breast cancer care agreed. "For decades we have been treating premenopausal women with chemotherapy, which decreases the risk of developing metastatic breast cancer and improves overall survival," said Dr. George Raptis, an oncologist at North Shore University Hospital in Manhasset, N.Y.
However, while many younger women survive their cancer, they find themselves "unable to reproduce" due to their treatment, he said.
In the new study, Albain's team tracked outcomes for 257 premenopausal women younger than 50, all of who had been diagnosed with early-stage breast cancer.
The women were randomly assigned to receive either standard chemotherapy or chemotherapy with goserelin (Zoladex).
After two years, 22 percent of the women who received standard chemotherapy had stopped menstruating or had reduced estrogen production and egg supply, compared with only 8 percent of those who had received goserelin.
Fertility got a boost, too: Pregnancy rates were 21 percent in the goserelin group and 11 percent in the standard chemotherapy group, the study found.
Goserelin works to shield fertility by temporarily putting the ovaries "at rest" during chemotherapy, Albain explained.
"We found that, in addition to reducing the risk of sudden, early menopause, and all of the symptoms that go along with menopause, goserelin was very safe and may even improve survival," she said.
The hint at improved survival was based on the fact that, after four years, 89 percent of women in the goserelin group had no signs or symptoms of cancer, compared with 78 percent of those in the standard chemotherapy group. Overall survival after four years was 92 percent in the goserelin group and 82 percent in the standard chemotherapy group, Albain's team found.
"Premenopausal women beginning chemotherapy for early breast cancer should consider this new option to prevent premature ovarian failure," the researchers wrote.
But Raptis cautioned that the study had its limitations.
"The study included women with estrogen- and progesterone-receptor-negative breast cancer [only], and it is unclear whether this can be generalized to include those with receptor-positive breast cancer at this time," he said.
Still, Raptis said the research marks a "potential practice-changing study that will improve the lives of countless young women undergoing chemotherapy."
Another breast cancer specialist agreed.
"The findings in this study are extremely exciting," said Dr. Stephanie Bernik, chief of surgical oncology at Lenox Hill Hospital in New York City.
"The use of goserelin not only reduced the rate of premature menopause, but also increased survival," she said. "All this was accomplished with little or no side effects -- goserelin offers these young women hope in trying times."
The U.S. National Cancer Institute has more about breast cancer treatment.