Published Early Breast Cancer Trialists' Collaborative Group overview results have been the beneficial effects of tamoxifen and ovarian ablation for pre and perimenopausal women with node negative breast cancer. Chemotherapy and Luteinizing Hormone Releasing Hormone (LHRH) agonists (medical ovarian ablation) have been shown to be effective adjuvant therapies for early stage breast cancer in several clinical trials however, the efficacy and tolerance of LHRH agonists in Korean breast cancer patients has not been evaluated.

Three thousand one hundred fifty breast cancer patients were treated at Asan Medical Center between January 2003 and December 2005. We selected 185 patients with node negative early breast cancer who were endocrine responsive (more than intermediate intensity), with a tumor size more than 1 cm, and who were reluctant to undergo chemotherapy due to the side effects. They received LHRH agonists (Zoladex® 3.6 mg) every 28 days with tamoxifen for two years. We prospectively evaluated mammography, chest PA, and physical examination every six months and evaluated the side effects and quality of life.

The mean age was 43.5 yr, and the mean tumor size was 1.62 cm. One hundred sixty-two patients had Stage I, and 23 Stage II disease. The incidence of severe menopausal symptoms was 24.1%, but these symptoms were reported to be "tolerable" during the two year follow-up. Quality of life and physical activity were essentially unchanged. The median follow-up duration was 18 months, and there was no local recurrence or distant metastases during the study.

Adjuvant therapy with LHRH agonists is safe and tolerable, and may be an alternative to chemotherapy for pre-and perimenopausal women with hormone responsive early breast cancer who are reluctant to undergo chemotherpy.