A Randomized Comparison of Medroxyprogesterone Acetate (MPA) and Observation For Prevention of Endometrial Pathology in Postmenopausal Breast Cancer Patients Treated with Tamoxifen

Primary unilateral or bilateral invasive adenoca of the breast, DCIS or LCIS WITH microinvasion; no "pure" LCIS, sarcoma, lymphoma, apocrine, adenocystic or squamous cell ca of the breast; no recurrent invasive breast ca; prior, ongoing or planned adjuvant chemotherapy OK; no prior hormonal treatment (other than tamoxifen) for breast ca; cannot be currently eligible or previously treated on any adjuvant intergroup study; no concurrent chemotherapy; must have had definitive local treatment of primary lesion and axillary node sampling or sentinal node biopsy required unless DCIS or LCIS as specified in protocol; patient must be candidate for tamoxifen, or ER and PgR unknown; tumor staged as T1-3, N0-1 and M0; currently free of disease, female, postmenopausal, no prior hysterectomy.

CANCER CONTROL CREDIT: 0.5
TREATMENT CREDIT: 0.8 (INCREASED FROM 0.5 TO 0.8 AS OF 6/1/99)