[Indications and limits of breast conserving treatment]

In Japan, 41% of surgeries for breast cancer were breast conserving treatment (BCT) in 2000. The indications for BCT in the guidelines of the Japanese Breast Cancer Society (1999) are as follows: (1) tumor size is 3 cm or less, (2) image diagnosis indicates no sign of extensive intraductal spread, (3) cases with multiple tumor are excluded, (4) radiation therapy is possible, (5) the patient wants to receive BCT. The pathological negative margin is favorable in BCT; however, we estimate based on our study that only about 30% of all breast cancers can be completely resected by partial mastectomy. To extend the indications for BCT, the roles of postoperative radiotherapy, endocrine therapy and preoperative chemotherapy will be important. Patients with ipsilateral breast tumor recurrence (IBTR) have increased risk of distant metastases, and the presence of IBTR is an important predictive factor for distant metastases. When we discuss the indications and limits of BCT, we have to take the rate of IBTR into careful consideration.