[Breast-conserving surgery without radiotherapy in the Cancer Institute Hospital, Tokyo].

We began performing breast-conserving surgery (BCS) in 1986 to achieve complete resection of breast cancer and omit postoperative radiotherapy (RT) if serial and detailed pathologic examination of the resected specimen within a 5-mm width showed that the of margin was cancer free. At of the end of 1998, 1,233 sides of the breast had been conserved, of which 827 sides were shown to have cancer-free margins. As of the end of 2001, with a mean observation period of 79 months, ipsilateral breast tumor recurrence was recognized on 46 sides (19 recurrences, 27 multiple cancers), for a recurrence rate 5.6% and an annual recurrence rate of 0.85%. This rate is slightly better than those reported by eminent institutions in the USA and Europe which all perform RT, confirming the accuracy and safety of our BCS.