Long-Term Outcome in Patients With Ductal Carcinoma In Situ Treated With Breast-Conserving Therapy: Implications for Optimal Follow-up Strategies

Purpose: To determine 20-year rates of local control and outcome-associated factors for ductal carcinoma in situ (DCIS) after breast-conserving therapy (BCT). Methods and Materials: All DCIS cases receiving BCT between 1980 and 1993 were reviewed. Patient demographics and pathologic factors were analyzed for effect on outcomes, including ipsilateral breast tumor recurrence (IBTR) and survival. Results: One hundred forty-five cases were evaluated; the median follow-up time was 19.3 years. IBTR developed in 25 patients, for 5-, 10-, 15-, and 20-year actuarial rates of 9.9%, 12.2%, 13.7%, and 17.5%, respectively. One third of IBTRs were elsewhere failures, and 68% of IBTRs occurred <10 years after diagnosis. Young age and cancerization of lobules predicted for IBTR at <10 years, and increased slide involvement and atypical ductal hyperplasia were associated with IBTR at later time points. Conclusions: Patients with DCIS treated with BCT have excellent long-term rates of local control. Predictors of IBTR vary over time, and the risk of recurrence seems highest within 10 to 12 years after diagnosis.