Examination of the clinical usefulness of TS-1 in locally recurrent breast cancer.

This study examined the therapeutic efficacy of TS-1 in the treatment of locally recurrent breast cancer. Between August 2006 and May 2009, 7 patients with local breast cancer recurrences were selected included in the study. The sites of recurrence were the cervical lymph nodes in 4 patients, the axillary lymph nodes in 2 and the thoracic wall in 1. Among the 7 patients, 6 were administered TS-1 as first-line treatment and 1 was administered TS-1 as second-line treatment. Complete response (CR) was achieved in 2 patients, 1 achieved partial response, 2 had stable disease (SD), 1 had long SD and 1 had progressive disease. The overall response rate was 43%, and the clinical benefit rate was 57%. A patient with recurrence of breast cancer in the thoracic wall 28 years after surgery also achieved CR following therapy. The only adverse event observed was a case of hand-foot syndrome in 1 patient. No patients withdrew from treatment, and favorable compliance was achieved in the study. The results indicated that TS-1 has the potential to be one of the drugs for first-line treatment of locally recurrent breast cancer.