Ten-year results comparing mastectomy to excision and radiation therapy for ductal carcinoma in situ of the breast.

The 10-year results of 300 patients with ductal carcinoma in situ (DCIS) without microinvasion are reported; 167 treated with mastectomy and 133 treated with excision and radiation therapy. There was a significant difference in disease-free survival at 10 years, in favour of those treated with mastectomy, 98% versus 81% (P = 0.0004). Multivariate analysis confirmed nuclear grade as the only significant predictor of local recurrence (P = 0.02) or invasive local recurrence (P = 0.03) in patients with DCIS treated with excision and radiation therapy. There was no difference in breast cancer-specific survival or overall survival between the two treatment groups.