May 21, 2007 (Insidermedicine) Pre-menopausal women with hormone-sensitive breast cancer have a new treatment option, according to research published in The Lancet. A molecule that blocks a hormone released from the brain, alone or in conjunction with chemotherapy or tamoxifen, provides an additional benefit in women under 40.

Breast cancer is a disease in which malignant – or cancerous – cells form in the tissue of the breast. It is the second leading cause of cancer deaths in women today, following lung cancer. The American Cancer Society estimates that nearly 180,000 new cases of invasive breast cancer will be diagnosed this year and about 40,000 women will die from it. Earlier detection and better treatments since the 1990s have led to steadily declining breast cancer death rates.

Some breast tumors need the hormone estrogen to grow. Luteinising hormone is produced in the pituitary gland- a small hormone-secreting gland located in the brain. This hormone stimulates ovulation and is an important in the womans ability to have a baby.

Luteinising-hormone-releasing hormone – or LHRH – agonists are molecules which mimic the action of luteinising hormone by binding to the same receptors within the pituitary gland, and block the signal for the production of estrogen. LHRH agonists can be thought of as a chemical
alternative to surgery to remove the ovaries.

To assess the effectiveness of LHRH agonists, researchers reviewed 16 studies using data from more than 11,000 pre-menopausal women with breast cancer. They found that LHRH agonists combined with chemotherapy or tamoxifen reduced breast cancer recurrence by nearly 13% and death by 15%, but only in women under age 40. Tamoxifen is another drug that blocks the production of estrogen, and is widely used to treat breast cancer.

This newest treatment provides another option for pre-menopausal women with hormone-sensitive breast cancer. In women with higher-risk disease, chemotherapy followed by tamoxifen should still be the standard treatment. The addition of an LHRH agonist may be considered to be a reasonable option for pre-menopausal women.

Reporting for Insidermedicine, I'm Dr. Yi Ning Strube.