Drug helps young breast cancer patients avoid early menopause

A drug can reduce the risk of infertility and early menopause in women undergoing chemotherapy for certain early stage breast cancers.

Supplementing chemotherapy with injections of a hormone-blocking drug, known as goserelin, significantly prevented failure of the ovaries and preserved fertility in women, according to the results of a phase III clinical trial published in The New England Journal of Medicine.

'Some of the most distressing side effects of chemotherapy in young women with breast cancer are early and sudden onset of menopause and infertility,' said Professor Kathy Albain, of Loyola University Chicago and a senior author on the study. 'We found that, in addition to reducing the risk of sudden, early menopause, and all of the symptoms that go along with menopause, goserelin was very safe and may even improve survival.'

With 1.7 million new cases in 2012, breast cancer is the most common cancer in women. Chemotherapy regimens include drugs such as cyclophosphamide (also used in the study), which damage the DNA of actively dividing cancer cells. However, these come with a downside in the form of collateral damage of ovarian cells - which precipitates early menopause and infertility. Concerns about these issues often factor into treatment decisions made by women.

Researchers studied 257 premenopausal women who were diagnosed with stage I to IIIA of a type of breast cancer that does not respond to hormones. Half of the women were randomly assigned to receive the chemotherapy drug cyclophosphamide along with injections of goserelin once every four weeks, whilst the rest received the chemotherapy drug alone. Two years later, 22 percent of women in the chemotherapy-alone group showed early menopause. They did not menstruate and had very low levels of fertility-associated hormones. However, only eight percent of women who received goserelin exhibited these symptoms.

Pregnancy rates showed the same trends - 21 percent of women in the goserelin group achieved at least one pregnancy versus 11 percent in the chemotherapy-alone group.

'Preserving ovarian function is a vital survivorship issue for young breast cancer patients. In addition to improving prospects for fertility, this intervention should help avoid a variety of unwanted effects of early menopause,' said Dr Halle Moore, lead investigator of the study and an oncologist at the Cleveland Clinic.

Goserelin is similar to hormones found in the body, and works by preventing the production of sex hormones. This causes the ovaries to temporarily enter an inactive state, thereby protecting the egg cells from any damage that chemotherapy can cause. The study included women with estrogen- and progesterone-receptor-negative breast cancer only.