Excision alone for small size ductal carcinoma in situ of the breast.

This study was performed to determine the risk of tumor recurrence after local excision alone in patients with small size (≤1 cm) ductal carcinoma in situ (DCIS) of the breast. We have treated 107 patients who had DCIS measuring ≤1 cm with margin widths of ≥0.3 cm with excision alone per institutional protocol. With a median follow-up time of 58 months, 4 patients developed ipsilateral breast tumor recurrence (IBTR). Two of the 4 recurrences were invasive, whereas 2 were DCIS. The 5-year rate of IBTR was 6.1%. The patients with resection margin of <1.0 cm had significantly higher rate of IBTR than the patients with resection margin of ≥1.0 cm (23.1% vs. 1.5% at 5-year, p < 0.01). In conclusion, radiotherapy is necessary in the patients with resection margin of <1.0 cm after excision alone because of the substantial risk of IBTR.