Among patients with breast cancer who consulted the Department of Radiology, Kochi Medical School to undergo breast-conservation treatment, toremifene (TOR) alone was administered to 7 postmenopausal women as initial treatment for reasons Such as the patient's desire, advanced age. and concomitant disease. In 6 patients, breast-conserving surgery was performed 1-12 months after the start of the administration of TOR alone. A 90-year-old patient has been treated with TOR alone for 56 months, and is being followed up. Six of 7 patients showed 50% or greater reduction of tumors, including 1 in whom the administration of TOR alone for 5 months reduced the tumor from a clinical diagnosis of skin invasion (T4b) to T1c, allowing lumpectomy under local anesthesia. In one patient, there were no changes (reduction ratio: 14%). No progressive disease was detected in any patient. In this study, the administration of TOR alone markedly reduced tumors in patients with estrogen receptor (ER)-positive breast cancer, facilitating down-staging. Treatment with TOR alone may be a useful neoadjuvant therapy or single therapy in elderly patients.