A retrospective analysis of 388 patients with pure ductal carcinoma in situ (DCIS) was performed in order to test the correlation of clearance margin of resection and other host-, tumor- and treatment-related factors with ipsilateral breast tumor recurrence (IBTR).

The pathological analysis was performed according to a standardized protocol: positive margins had DCIS at the inked margin; close margins had tumor between 0.1 to 0.9 mm, or 1 to 1.9 mm, and negative margins were ≥2 mm.

At a median follow-up of 90 months there were 26 IBTR (10 invasive and 16 DCIS). Both in univariate and multivariate analysis a significant difference was observed in IBTR by comparing positive versus close/negative margins of excision (p=0.05) and the number of re-operations (p=0.000). Moreover, the actuarial IBTR rates were significantly different in patients with a positive compared to close/negative margins (log-rank test, p=0.042) while the stratification by the margin width (0.1-0.9 mm; 1.0-1.9 mm; ≥2 mm) was not significant (log-rank test, p=0.243).

The policy of "no ink on the tumor" can be translated from invasive to DCIS, because the actuarial IBTR rates were significantly different only in patients with a positive, compared to close/negative margins.