OBJECTIVES: I. Determine the maximum tolerated dose and dose-limiting toxicity of yttrium Y 90 monoclonal antibody MN-14 (Y90 MOAB MN-14) plus peripheral blood stem cell rescue in patients with stage IV breast cancer. II. Determine the pharmacokinetic profile of Y90 MOAB MN-14 in the blood, normal organs, and tumors of this patient population. III. Determine the antibody response to Y90 MOAB MN-14 in these patients. IV. Determine the antitumor effect of this regimen in these patients. V. Determine the radiation absorbed dose to normal organs and tumors.