The early results of a study of chemotherapy-induced infertility suggest that the hormone inhibin A may be a marker of premature ovarian failure in premenopausal women being treated for breast cancer, according to a presentation at the annual San Antonio Breast Cancer Symposium.

“Our primary goal was to correlate hormonal markers with premature ovarian failure among women receiving chemotherapy for nonmetastatic breast cancer,” said presenter Dr. Carey Anders from Duke University in Durham, North Carolina.

So far, Anders and colleagues have results for 30 women whose hormone levels were measured prior to chemotherapy and 6 months later. Ultimately, the investigators plan to enroll 120 women and to follow them for 12 months after the completion of chemotherapy.

“Even among the first 30 patients, we’re seeing trends, especially in inhibin A,” Dr. Anders said. Inhibin A is a marker of the ovary’s luteal phase, which occurs between day 18 and day 24 of the menstrual cycle.

Inhibin A levels among women whose menses had not returned by 60 months were 57.4 units before treatment and 2.5 afterward. In contrast, women who maintained their menstrual cycle had levels of 83.4 and 22.6, respectively.

“This marker would be helpful for woman who still hope to have children,” Anders noted. “If she has low inhibin A levels before starting chemotherapy, the oncologist could advise her that if she is thinking about fertility in the future she should see a reproductive endocrinologist up front, because her menses are unlikely to return.”

However, no firm conclusions can yet be drawn, until more women have been evaluated and 12-month results are documented.