Breast-conserving therapy for ductal carcinoma in situ: a 20-year experience with excision plus radiation therapy.

Breast conservation therapy is a practical alternative to mastectomy for the treatment of ductal carcinoma in situ (DCIS). The role of radiation therapy after excision for DCIS has been debated, however, its value in reducing recurrence has been proven by multiple prospective randomized trials and is well accepted. We examined a prospective database of 260 patients treated for DCIS with excision and radiation from 1979 to 2002. Two different treatment regimens were examined for local recurrence-free survival. Patients treated with radiation therapy 4 days per week were compared with patients treated 5 days per week. The total doses were similar for both groups; boost types differed. Local recurrence as a function of other factors, including nuclear grade, comedonecrosis, and margin width was evaluated. The median time to local recurrence was 61 months for patients treated 4 days per week compared with 52 months for patients treated 5 days per week (P = not significant). There was no statistical difference in the Kaplan-Meier detailing the probability of local recurrence-free survival for patients treated 4 days per week versus patients treated 5 days per week. Overall, cosmetic results between the two groups were equivalent. The comparison of two different radiation treatment regimens shows no difference in local disease-free survival or cosmetic result.