Letrozole, low-dose FSH lead to IVF pregnancy.(Gynecology)

PHILADELPHIA -- Researchers at New York's Cornell University have announced the first pregnancy after in vitro fertilization in a breast cancer patient whose ovaries were stimulated with letrozole and low-dose follicle stimulating hormone.

Standard ovarian stimulation agents are not considered safe in breast cancer patients because they increase estrogen levels. But letrozole, an aromatase inhibitor that is also used to treat breast cancer, can stimulate oocyte production with out raising estrogen levels, making it ideal for this patient population.

"We think this protocol can be given first priority in these patients," Kutluk Oktay, M.D., said at the annual meeting of the American Society for Reproductive Medicine.

"This could be a new twist in ovarian stimulation. I think this may be a protocol that we could possibly use for everybody," he said in an interview.

The pregnancy occurred during a study in breast cancer patients undergoing embryo freezing before chemotherapy. Sixty-five breast cancer patients were enrolled in the study, 33 of whom were undergoing ovarian stimulation, in vitro fertilization (IVF), and embryo freezing. A control group of 32 patients did not undergo IVF.

The IVF patients were divided into three groups, each of which received a different ovarian stimulation regimen: 60 mg/day of tamoxifen alone; 60 mg/day of tamoxifen plus low-dose FSH; or 5 mg/day of letrozole plus low-dose FSH.

Patients in the tamoxifen/FSH and letrozole/FSH groups had more eggs retrieved and more embryos created than did those on tamoxifen alone. In addition, the letrozole/FSH group had the lowest estrogen levels during stimulation but the highest yield ...