- Patients must have an analysis of both estrogen and progesterone receptors on the primary tumor performed prior to randomization. Tumors will be defined as ER or progesterone receptor (PgR) positive if: 1) the Dextran-coated charcoal or sucrose-density gradient method shows them to have greater than or equal to 10 fmol/mg cytosol protein, or 2) if using individual laboratory criteria they can be shown to be positive by the enzyme immunoassay method (EIA) or immunocytochemical assay. "Marginal or borderline," results (i.e., those not definitively negative) will also be considered positive.