Outcomes and factors impacting local recurrence of ductal carcinoma in situ

BACKGROUND, The optimal management of ductal carcinoma in situ (DCIS) remai ns controversial. Investigators have focused on identifying patients who ar e eligible for treatment by excision alone. A retrospective analysis of pat ients with DCIS treated by various modalities was conducted to compare outc omes and determine factors significant for local recurrence (LR). METHODS, Between 1985-1992, 88 consecutive diagnoses of DCIS were identifie d in 85 patients. Seventy-four percent were detected mammographically. The most common histologic subtypes were comedo (54%) and cribriform (23%). Tum or sizes were < 2.5 cm (49%), > 2.5-5 cm (26%), > 5 cm (23%), and unknown ( 2%). Final resection margins were tumor free (75%), close/positive (23%), a nd unknown (2%). Treatment methods included mastectomy (30%), localized sur gery and radiation therapy (LSR) (43%), or wide localized surgery alone (LS ) (27%). Radiation therapy (RT) was comprised of 50 grays to the breast, an d 53% of treated patients received local "boost" irradiation. RESULTS. The median follow up was 8.3 years. The overall recurrence rate wa s 13.6%, whereas the median time to LR was 27.8 months. Recurrence rates ac cording to treatment modality were: LS: 25%; LSR: 13%; and mastectomy: 4%. However, if surgical margins were tumor free, LSR had a LR rate of 3.4%. Af ter RT, no LR occurred prior to 15 months, and 4 of 5 tumors were noninvasi ve. Nine patients treated by excision alone conformed to the criteria of La gios et al. criteria and LR occurred in three of nine tumors. Of the factor s analyzed, margin status was found to be the best predictor for LR (P = 0. 05). CONCLUSIONS. If surgical margins are tumor free, the LSR regimen is equival ent to mastectomy for local tumor control. Annual mammograms may be adequat e for the follow-up of patients with irradiated breasts, but biannual studi es still are recommended for patients treated with excision alone. (C) 2000 American Cancer Society.