Investigation of menstruation recovery after LH-RH agonist therapy for premenopausal patients with breast cancer

Background: Recently Luteinizing hormone-releasing hormone (LH-RH) agonist has been used for premenopausal patients with breast cancer as endocrine therapy. However, there is no consensus regarding recovery of menstruation after long-term treatment with LH-RH agonist. We investigated recovery of menstruation after this treatment. Methods: We investigated 28 premenopausal patients with breast cancer who underwent operation at Chiba Cancer Center Hospital in 1995 or 1996. The patients were treated with LH-RH agonist (goserelin) for 24 months as an adjuvant therapy, and were observed for more than 6 months after the last goserelin depot. Ages ranged 31-55 years old from at the time of last treatment. We defined recovery of menstruation as regular menstruation occurring more than three times. Results: There were 22 patients in the recovery group (range: 31-53 years, mean 45.1 years). There were 6 patients in the non-recovery group (range: 50-55 years, mean 52.2 years). The overall recovery rate was 78.6%. Recovery rate was 81.8% for the patients under 50 years, and 66.7% for over 51 years. We separated all patients into groups by age at 5 years intervals, and investigated the distribution of the recovery time. In the recovery group (22 patients), there were 15 patients (68.2%) who confirmed recovery of menstruation within 6 months. Conclusion: Our investigation suggested that the recovery of menstruation after this therapy would occur in those less than 50 years old, within 6 months from the last treatment.