Toremifene, a drug that blocks the effects of estrogen and is used to treat breast cancer, also relieves premenstrual breast pain and tenderness without causing any major side effects, according to the results of a study published the British Journal of Obstetrics and Gynecology.

Dr. Sinikka Oksa, of Satakunta Central Hospital, Pori, Finland, and colleagues conducted a study with 62 women between the ages of 25 and 45 years who had premenstrual breast pain during at least three previous menstrual cycles.

The subjects were randomly assigned to receive 20 mg toremifene daily or placebo from day 15 of the menstrual cycle until menstruation for three consecutive cycles. Following a cycle in which no drugs were administered, the women were switched to the other treatment for three additional cycles. Fifty-six women completed the study.

The researchers used a visual analogue scale (VAS) to assess the relief of breast pain and a modified Finnish Depression scale to measure quality of life. The team also evaluated the acceptability of treatment by the patients.

When the toremifene cycles were compared with the placebo cycles and with the menstrual cycle before the study began, the average VAS scores were 1.8, 3.7, and 5.0, respectively, with higher scores indicating greater relief, Oksa’s team reports. They estimate that there was a 64-percent reduction in the average pain scores in the toremifene-treated cycles compared with a 26-percent reduction in the placebo-treated cycles, a significant difference.

However, no differences in quality of life were found between the toremifene and placebo cycles.

Adverse events were mild and were similar with toremifene and placebo treatments. None of the women withdrew from the study because of adverse events.

Oksa and colleagues say that they are encouraged by the results, and plan to study the long-term safety of toremifene and compare it with other drugs, such as tamoxifen.

In the United States, toremifene is sold under the trade name Fareston.

SOURCE: British Journal of Obstetrics and Gynecology, June 2006.