Feasibility of breast-conserving therapy for macroscopically multiple ipsilateral breast cancer.

Macroscopically multiple ipsilateral breast cancer (MMIBC) is generally considered a contraindication for breast-conserving therapy (BCT). The result of BCT for MMIBC is reported and the feasibility discussed.Between July 1993 and February 1999, 34 patients with MMIBC underwent BCT at our clinic. The local control, disease-free survival, and cosmetic results in these patients were compared with those of patients with single disease.After wide excision, 21 (62%) of 34 patients with MMIBC had a close surgical margin and the rate was significantly greater than that of patients with a single lesion. However, the size of the boost irradiation field was not significantly increased. At a median follow-up of 98 months, no statistically significant difference was noted in local control, disease-free survival, or cosmetic result compared with patients with a single lesion.Although patients with MMIBC frequently had close surgical margins after BCT, it can be a treatment option for these patients as long as the close surgical margin is accurately detected and treated with an appropriate radiation technique.