Clinical Question: Is toremifene (Fareston) an effective treatment for mastalgia?

Setting: Outpatient (specialty)

Study Design: Randomized controlled trial (double-blinded)

Allocation: Concealed

Synopsis: Mastalgia (i.e., painful symptoms of the breast) is the most common clinical complaint in women with benign breast disease. Toremifene is a new selective estrogen receptor modulator that is equally as effective as, but less toxic than, tamoxifen (Nolvadex) in the treatment of breast cancer. To evaluate the benefit of toremifene for the treatment of mastalgia, the investigators performed a randomized, double-blind (concealed allocation assignment) trial of 195 women with persistent (i.e., lasting longer than six months) mastalgia. They assigned patients to toremifene 30 mg daily or matched placebo for three menstrual cycles. Patients were recruited from a breast disease pain clinic, and from this group the authors included only the most severe cases. Thus, generalizability to routine practice is suspect.

Participants were blinded to treatment group assignment and self-reported the severity of breast pain using a visual analog scale from 0 (no pain) to 10 (worst pain). A 50 percent reduction in total pain score for the three months met criteria for a clinically significant treatment response. Follow-up occurred for all subjects at three months. Using intention-to-treat analysis, women receiving toremifene reported a significant reduction in total breast pain compared with those receiving placebo (69.2 versus 31.9 percent, respectively; number needed to treat = 3; 95% confidence interval, 2 to 4). Women with cyclical mastalgia had a higher response rate to toremifene than those with noncyclical pain. Adverse events in both groups included menses disturbance, dizziness, vaginal discharge, and nausea. Overall, the incidences of adverse events were the same in both groups.

Bottom Line: Toremifene effectively relieves moderate to severe mastalgia. Women with cyclical mastalgia received the greatest treatment benefit. (Level of Evidence: 1b)