Hormone drug type shows survival difference in breast cancer

Aromatase inhibitors are drugs such as Arimidex, Aromasin and Femara, which have been available for the past decade or so.

According to review co-author Judith Bliss, of the Institute of Cancer Research in London, these are less likely to cause blood clots and vaginal bleeding than other hormone treatments. The data showed an 11% reduction in the risk of death compared to women not receiving aromatase inhibitors.

In many breast cancers, estrogen stimulates tumor growth. Aromatase inhibitors work by limiting a woman's production of estrogen. Other breast cancer treatments that also affect estrogen include tamoxifen and progestins.

In general, women taking aromatase inhibitors had about the same risk of experiencing hot flashes as those receiving tamoxifen. However, they reported more nausea, vomiting and diarrhea when compared to patients receiving the progestin drug megestrol acetate and, to a lesser extent, when compared with patients receiving tamoxifen.

Edith Perez, an oncologist at the Mayo Clinic, said that the drugs are good but do carry a risk of increased joint aches and may cause bone loss. She recommended patients having bone density tests before using these drugs.

The researchers said that the findings do confirm modest but real therapeutic benefits from the use of aromatase inhibitors in a variety of clinical settings.