In a study of 12 breast cancer patients, doctors found that by giving women tamoxifen, more eggs than normal could be retrieved, says Kutluk Oktay, MD, assistant professor of reproductive endocrinology at the Weill Medical College of Cornell University in New York.
Every patient in his study had one or more embryos that were either immediately transferred or frozen for later attempts at pregnancy. Now two years' later, two pregnancies have occurred -- one involving a set of twins, he tells WebMD.
Oktay's paper appears in the January edition of the European medical journal Human Reproduction.
Reduced fertility and ovarian failure occur with the chemotherapy drug cyclophosphamide. Young women treated for breast cancer typically receive four to six weeks of chemotherapy that uses several drugs including cyclophosphamide. With each round of chemotherapy, their ovaries become more damaged and less able to produce eggs; the drug also destroys eggs the ovaries hold in reserve.
Breast oncologists do not advise their patients to undergo standard infertility treatments because fertility drugs are geared to raise estrogen levels -- "which would be like pouring gasoline on fire," he says.
Also, many experts do not recommend that breast cancer patients get pregnant for at least two to five years after cancer diagnosis and treatment, he says. By that time, many women face fertility problems because of their age and their lack of reserve eggs.
Because of these problems, many women have tried various methods to get pregnant, such as having ovaries removed and frozen before chemotherapy, then transplanted later. Thus far, no pregnancies have occurred, Oktay says.
That's where tamoxifen can help. Originally developed as a contraceptive in the 1960s, the drug's ability to stimulate egg production became apparent when women began getting pregnant "left and right," Oktay tells WebMD. Tamoxifen then became a drug used to treat infertility.
In this current study, 12 women with breast cancer received tamoxifen treatments on the second and third days of their menstrual cycle. There was a total of 15 cycles in these 12 patients. When compared with the control group, the women taking tamoxifen had a greater number of mature eggs and a significantly higher number of embryos. All of the tamoxifen-treated patients generated embryos.
After an average follow-up of 15 months, none of the patients had a recurrence of cancer, he reports.
Celia E. Dominguez, MD, assistant professor of reproductive endocrinology and infertility at Emory University School of Medicine in Atlanta, applauds Oktay's work as a "novel idea."
The Cornell researchers are "the experts" in in vitro fertilization, she tells WebMD. "This is a little silver lining, a ray of hope for women who are devastated with news about cancer.
"Any young woman, before she undergoes chemotherapy, needs to see an endocrinologist to discuss fertility," says Dominguez. "Many young women don't realize there are options."
The women in Oktay's study may have had success because the treatment occurred before they had chemotherapy, says Dominguez. "If we can get [these patients] in that window, between surgery and chemotherapy, there is real hope for them."