Predictors of local recurrence following excision alone for ductal carcinoma in situ.

BACKGROUND: The treatment of ductal carcinoma in situ (DCIS) remains controversial, particularly in regard to the selection of patients who may be appropriately treated with wide excision alone. To help identify such patients, the authors assessed prognostic factors for local recurrence in patients with DCIS treated with excision alone.

METHODS: The study population consisted of 59 patients diagnosed with DCIS between 1985 and 1990. All had been treated with excision alone, had their histologic slides available for re-review by a study pathologist, and had negative margins of excision on review. The median age at diagnosis was 54 years, and the median follow-up time was 95.5 months. Ninety-six percent presented with mammographic findings only; all patients had a reexcision. The size of the DCIS was assessed by the total number of low-power fields (LPF) in which DCIS was present (median LPF = 5).

RESULTS: Ten patients experienced a local recurrence (LR) at 5-132 months (median, 37 months) after excision. The actuarial 5-year LR rate was 10%. Four of the recurrences were invasive carcinomas, and 6 were DCIS. No patients have developed metastatic disease or have died of disease. Lesion size >5 LPF was the only significant prognostic factor for local recurrence on univariate analysis (3% vs. 17% for < or = 5 vs. > or = 5 LPF, P = 0.02) and in proportional hazards models. Although patients with nuclear Grade 3 lesions had a higher LR rate than those with nuclear Grade 1 and 2 lesions (18% vs. 6% and 5%, respectively) and patients with close margins (< or = 1 mm) had a higher LR rate than patients with negative margins (>1 mm) (25% vs. 8%), these differences did not reach statistical significance. Among the 19 cases with margins negative by more than 1 mm, lesion size < or = 5 LPF, and nuclear Grade 1 or 2, there were no LRs; by contrast, the remaining 40 patients had a 5-year actuarial LR rate of 15% (P = 0.08).

CONCLUSIONS: Lesion size was the only statistically significant prognostic factor for local recurrence in this series of patients with DCIS treated with excision alone. Other factors, such as margin status and nuclear grade, may also be useful in the identification of patients with DCIS who can be managed with excision alone. However, the most reliable and reproducible method of assessing these factors and the best way to combine them have not been determined.