Ductal carcinoma-in-situ: Long-term results of breast-conserving therapy

Background: The role of breast-conserving therapy (BCT) in the management of ductal carcinoma-in-situ (DCIS) is controversial because of reported high recurrence rates. We reviewed our experience to determine whether the rate and pattern of locoregional recurrence after BCT were similar in patients with DCIS and patients with early-stage (T1) invasive breast tumors and whether local recurrence affected survival. Methods: Between 1973 and 1994, 87 patients with DCIS alone, 22 patients with DCIS with microinvasion (DCIS-M), and 646 patients with invasive breast cancer 2 cm or smaller in diameter were treated with BCT (wide local excision with radiotherapy) at The University of Texas M. D. Anderson Cancer Center. Survival was calculated by the Kaplan-Meier method. The median follow-up times were 11 years for patients with DCIS alone, 12 years for patients with DCIS-M, and 8 years for patients with invasive breast cancer. Results: Eleven (13%) of 87 patients with DCIS and 5 (23%) of 22 patients with DCIS-M had developed locoregional recurrences at follow-up. Two patients with DCIS with locoregional recurrence died of breast cancer. Of the 646 patients with invasive breast cancer, 56 (9%) had a locoregional recurrence, and 16 (2%) died of breast cancer. The median time to locoregional recurrence was significantly longer in patients with DCIS or DCIS-M (9-10 years) than patients with invasive tumors (5 years). Conclusions: DCIS is a favorable disease with an excellent long-term survival. The locoregional recurrence rate in patients with DCIS treated with BCT is similar to that in patients with early-stage invasive breast cancer treated with BCT, but time to locoregional recurrence is significantly longer in patients with DCIS. In patients with DCIS treated with BCT, intense surveillance for locoregional recurrence needs to be maintained for the patient's lifetime.