A Clinical Trial to Evaluate the Benefit of Adding Octreotide (SMS 201-995 PA LAR) to Tamoxifen Alone or to Tamoxifen and Chemotherapy in Patients With Axillary Node-Negative, Estrogen-Receptor-Positive, Primary Invasive Breast Cancer

OBJECTIVES: I. Determine whether the addition of octreotide pamoate to tamoxifen alone or to tamoxifen and chemotherapy improves the disease free survival of patients with primary invasive breast cancer with estrogen receptor (ER) positive tumors and histologically negative axillary lymph nodes or histologically negative sentinel lymph nodes if participating in NSABP B-32. II. Determine whether the rate of endometrial cancer associated with tamoxifen is altered by the concurrent administration of octreotide pamoate. III. Determine whether the addition of octreotide pamoate to tamoxifen decreases the rate of opposite breast cancer more than tamoxifen alone. IV. Evaluate the incidence of gallstone formation (including the development of symptoms and complications of biliary tract disease), hyper and hypoglycemia, hypothyroidism, and vitamin B12 deficiency in patients treated with octreotide pamoate in comparison with patients not treated with octreotide pamoate.

OUTLINE: This is a randomized study. Patients are randomized into one of four treatment arms. Arm I: Patients receive oral tamoxifen (TMX) daily continously for 5 years. Lumpectomy patients receive breast radiotherapy following recovery from surgery. Arm II: Patients receive TMX as in Arm I and octreotide pamoate (SMS 201-995 pa LAR) intramuscularly (IM) every 21 days for 4 doses, followed by octreotide pamoate IM for 28 days for 23 additional doses. Lumpectomy patients receive breast radiotherapy following recovery from surgery. Arm III: Patients receive doxorubicin (DOX) IV and cyclophosphamide (CTX) IV every 3 weeks for 4 courses and TMX as in Arm I. Lumpectomy patients receive breast radiotherapy after recovery from chemotherapy. Arm IV: Patients receive DOX and CTX as in Arm III, TMX as in Arm I, and octreotide pamoate as in Arm II. Patients receive TMX and octreotide pamoate on day 1 of first course of chemotherapy. Lumpectomy patients receive breast radiotherapy after recovery from chemotherapy.

PROJECTED ACCRUAL: Total accrual of 3,000 patients will be acrrued for this study over 5 years.