Drug helps breast cancer patients keep fertility
By Marilynn Marchione, AP
June 1, 2014, 12:00 am TWN
CHICAGO--Doctors may have found a way to help young breast cancer patients avoid infertility caused by chemotherapy. Giving a drug to shut down the ovaries temporarily seems to boost the odds they will work after treatment ends, and it might even improve survival, a study found.
"They're really exciting findings" that could help thousands of women each year in the United States alone, said the global study's leader, Dr. Halle Moore of the Cleveland Clinic.
"This has implications far beyond breast cancer," for young women with other types of tumors, too, added Dr. Clifford Hudis, breast cancer chief at Memorial Sloan Kettering Cancer Center in New York City.
He is president of the American Society of Clinical Oncology, which featured the study at its annual conference in Chicago on Friday. More than 30,000 cancer specialists from around the world are attending.
Chemotherapy often causes premature ovarian failure, or early menopause. Doctors think that active ovaries are more susceptible to chemo damage, and that making them go dormant and stopping a woman's monthly cycles might help shield them from harm.
"It's basically a temporary menopause to prevent permanent menopause," Moore explained.
The study involved 257 women around the world under age 50 with breast cancers whose growth is not fueled by estrogen. They all had standard chemo and half also had monthly shots of goserelin, a drug to lower estrogen and temporarily put the ovaries at rest. Its main side effects are menopause symptoms — hot flashes and vaginal dryness.
Doctors then tracked the women to see how the treatments affected fertility.
After two years, full results were available on 135 participants. Only 8 percent of those given the shots became menopausal versus 22 percent of the others who didn't get them. There were 22 pregnancies in the drug group versus 12 in the other one. That's encouraging, but firm comparisons can't really be made because not all women may have been trying to conceive, and other factors such as a partner's fertility play a role.
Still, "the difference was enough that in spite of all the limitations in the study, we were pretty convincingly able to see an effect," Moore said.
The benefits go beyond preserving fertility, said Dr. Kathy Albain, a breast cancer specialist at Chicago's Loyola University and one of the study leaders.
"Some women don't care about having children" after breast cancer, but would like to avoid "being jolted into early menopause" by chemo treatment, she said.
Surprisingly, doctors also saw better survival among women given goserelin. About four years after treatment, 92 percent of them were alive versus 82 percent of the others. Again, an encouraging result, but the study was too small to determine whether ovarian suppression truly affects survival.
The National Institutes of Health sponsored the study, and researchers originally aimed to enroll 400 women but had to scale back because of government budget cuts.
"The findings are quite provocative," said one independent expert, Dr. Sharon Giordano, a breast cancer specialist at the University of Texas MD Anderson Cancer Center in Houston. "Using goserelin is an option I would discuss with selected patients" but it doesn't guarantee fertility preservation.
Women may want to consider other options, such as creating and freezing embryos to use after cancer treatment ends, Giordano said.