A 38-year-old woman with cancer in the left breast underwent standard radical mastectomy. The estrogen receptor and progesterone receptor status of the primary tumor was unknown. Ten years after the surgery, a metastatic liver tumor was detected, and chemoendocrine therapy, consisting of cyclophosphamide, epirubicin, 5-fluorouracil (CEF) and medroxyprogesterone acetate (MPA) was initiated. The metastatic liver tumor showed a partial response after 11 cycles of such chemoendocrine therapy. Subsequently, MPA alone was given daily as maintenance therapy, and the disease has remained stable for 6 years. For women with metastatic breast cancer, complete remission is uncommon, and stable disease is a reasonable goal of successful therapy. In this respect, chemoendocrine therapy with CEF and MPA, followed by MPA alone as maintenance therapy, was successful in the patient reported here. Importantly, the patient's quality of life has remained favorable for several years after the partial response was achieved.