Chemotherapy is often a last resort to treating breast cancer, and in at least 40% of those women, menstrual cycles are effected including the complete absence of menstruation. New research shows that temporarily suppressing ovarian function with use of the hormone analogue triptorelin reduced the occurrence of early menopause induced by chemotherapy among women with breast cancer.

No standard strategies for preventing chemotherapy induced ovarian failure are yet available, but preclinical data have suggested that temporary ovarian suppression with a gonadotropin releasing hormone (GnRH) analogue (chemical compound) during chemotherapy reduces ovarian toxicity.

Approximately 6% of women with breast cancer are diagnosed before age 40 years, with the majority of young patients receiving systemic treatment with chemotherapy, hormonal therapy, or both.

Italian researchers assessed the efficacy of temporary ovarian suppression induced by the GnRH analogue triptorelin in reducing the incidence of early menopause in young women with breast cancer undergoing supplemental or chemo before surgery. The patients were premenopausal women with stage I through III breast cancer who were candidates for adjuvant or neoadjuvant chemotherapy. Subjects were randomly allocated to receive chemotherapy alone or combined with triptorelin, which was administered intramuscularly at least one week before the start of chemotherapy and then every 4 weeks for the duration of chemotherapy.

The researchers found that the rate of early menopause was 25.9% in the chemotherapy-alone group and 8.9% in the chemotherapy plus triptorelin group, an absolute difference of 17%.

Further analysis showed that only treatment with triptorelin was associated with a significant reduction of the risk of developing early menopause. Patient age and the type of chemotherapy did not significantly affect the risk.

Resumption of menses was observed in 60 patients in the chemotherapy-alone group (49.6%) and in 88 in the chemotherapy plus triptorelin group (63.3%).

The conclusion is, according to the scientists:

"Our results suggest that temporarily suppressing ovarian function by administering triptorelin reduces the incidence of chemotherapy-induced early menopause. This treatment can therefore be offered to premenopausal patients with breast cancer who wish to decrease the risk of permanent ovarian failure associated with chemotherapy."

It is already known that during the treatment of prostate cancer triptorelin does cause a surge of testosterone (an initial uplevel of testosterone levels), known as a flare effect. In men a reduction of serum testosterone levels into the range normally seen after surgical castration occurs approximately two to four weeks after initiation of therapy. In contrast, gonadotropin-releasing hormone antagonists do not cause a surge, but a sudden reduction of testosterone levels.

Hope S. Rugo, M.D., and Mitchell P. Rosen, M.D., of the University of California, San Francisco provide additional insight:

"International guidelines recommend discussion of fertility options before starting chemotherapy, and when possible before surgery, to allow optimal timing for consultation and oocyte [egg cell] harvesting. When feasible, and for patients with hormone-insensitive disease, GnRH agonist therapy to suppress ovarian function during chemotherapy is an additional treatment that can potentially expand fertility possibilities. Although recovering menses is not the same as fertility preservation, it is one step in the right direction."

Source: The Journal of the American Medical Association

Sy Kraft