OBJECTIVES: I. Determine if immunization with glycosylated MUC-1 antigen containing MUC-1(106) or MUC-1(33) with keyhole limpet hemocyanin conjugate plus immunological adjuvant QS21 induces an antibody, helper T cell and/or cytotoxic T cell response against MUC-1 in patients with high risk breast cancer expressing MUC-1.