Aims: To find out if there is any link between the therapeutic effect of toremifene on premenstrual mastalgia and luteal phase serum inhibin A and/or B levels.
Methods: Forty-eight patients participating in a randomized cross-over trial on toremifene vs. placebo for premenstrual mastalgia gave three blood samples during the luteal phase of the menstrual cycle: the first at baseline, the second during the third toremifene/placebo cycle, and the third during the third placebo/toremifene cycle, respectively. The blood samples were analyzed for inhibin A and B with respective specific two-site enzyme-linked immunosorbent assays. Toremifene (20 mg/d) and placebo were administered during the luteal phase only.
Results: When all the toremifene-treated cycles were compared with all the placebo cycles and with the baseline, the median inhibin A levels were 42, 38, and 40 pg/ml, respectively (baseline versus toremifene, p = 0.638; baseline versus placebo, p = 0.468; and toremifene versus placebo, p = 0.365). The median inhibin B levels were at baseline 19 ng/l, during placebo 20 ng/l, and during toremifene 17 ng/l (baseline versus toremifene, p = 0.983; baseline versus placebo, p = 0.519; and toremifene versus placebo, p = 0.880).
Conclusion: A luteal administration of toremifene does not seem to result in any changes in mid-luteal concentrations of inhibin A or B in serum.