High-dose chemotherapy and bone marrow transplant (HDC/BMT), also high-dose chemotherapy with autologous bone marrow transplant (HDC/ABMT or just ABMT), was a treatment regimen for metastatic breast cancer, and later high-risk breast cancer, that was considered promising during the 1980s and 1990s. It was ultimately determined to be no more effective than normal treatment, and to have significantly higher side effects, including treatment-related death.