DISEASE CHARACTERISTICS: Primary operable stage I (tumors at least 1 cm), stage II, and stage IIIA invasive breast carcinoma Treatment within the past 4 years by total mastectomy and axillary dissection, or breast sparing surgical removal of cancer with clear macroscopic margins and axillary dissection followed by adjuvant breast radiation No evidence of recurrent disease or new breast cancer since completion of initial local treatment confirmed within the past 6 months by physician evaluation, except stage I mastectomy, for which physician evaluation can be within 1 year prior to randomization Hormone receptor status: Not specified