The patient was a 70-year-old woman, who became aware of a mass in her right breast in 2001, but left it untreated. On March 10, 2003, she visited a nearby doctor with the chief complaint of dyspnea. Since a large painful mass was palpable in the right breast, advanced right breast cancer was suspected, and the patient was referred to our department. Examination revealed the presence of right axillary lymph node metastasis, left pleural effusion, and left atelectasis, and the patient was admitted to our hospital on an emergency basis. Two cycles of CMF were begun on April 2, but CT indicated NC to PD. Therefore, exemestane (EXE, 25 mg/day), was administered on May 13. While the size of the primary lesion was partially decreased, the tumor marker levels were increasing markedly. Administration of EXE was therefore discontinued, and toremifene (TOR, 120 mg/day), was begun. The systemic condition began to improve one month after the start of TOR administration. Two months later, the primary lesion had decreased in size. At after 9 months of TOR treatment, the size of the primary lesion and the tumor marker levels continued to decrease, and both the left pleural effusion and the left atelectasis disappeared.