A Randomized Trial of Antiestrogen Therapy Versus Combined Antiestrogen and Octreotide Therapy in the Adjuvant Treatment of Breast Cancer in Post-Menopausal Women

OBJECTIVES: I. Compare event-free, recurrence-free, and overall survival following adjuvant therapy with tamoxifen alone vs. tamoxifen plus octreotide long-acting release formulation in postmenopausal women with stage I/II/III breast cancer. II. Compare the toxicity and quality of life associated with each treatment regimen. III. Compare the effects of each treatment regimen on insulin-like growth factor-I (IGF-I) physiology, and study the relationship between IGF-I physiology and outcome.

OUTLINE: This is a randomized study. Patients are stratified by participating institution, when and whether they receive adjuvant chemotherapy, axillary lymph node status, and hormone receptor status. All patients are randomized within 12 weeks of definitive surgery. Patients receiving adjuvant chemotherapy prior to protocol treatment are randomized within 6 weeks after the last dose of chemotherapy. One group of patients receives daily oral tamoxifen, while a second group receives daily oral tamoxifen plus octreotide (long-acting release formulation) by monthly depot injection. Treatment in both groups continues for 5 years or until disease recurrence or development of a second malignancy. Patients are followed monthly for 4 months, every 4 months for 3 years, and every 6 months thereafter.

PROJECTED ACCRUAL: A total of 850 patients will be entered over 4.2 years in this multicenter study.