Margin width should not still enforce a systematic surgical re-excision in the conservative treatment of early breast infiltrative ductal carcinoma.

Background: In cases where breast conservative surgery was performed for infiltrative ductal carcinoma (IDC), margin status is an independent prognostic factor for local ipsilateral relapse (LIR). There is no validated definition of a clear margin. We investigated factors associated with residual disease on re-excision specimen and the impact of margin status on the risk of LIR.
Methods: From January 1992 to December 2002, 454 patients were retrospectively included. Patients had undergone conservative surgery and radiotherapy for IDC. Two groups were defined: group 1, involved or close margin (<3 mm) and a re-excision; and group 2, involved or close margin without re-excision. The risk factors for residual disease in the re-excision specimen were analyzed in group 1, and the rate of 5-year LIR was analyzed in both groups.
Results: Among patients who experienced a surgical re-excision for involved or close margin, 21% (55 of 206) had residual tumor. The multivariate analysis showed that only a margin involved with intraductal carcinoma remained predictive for residual disease. According to the multivariate analysis, only hormone therapy (p < 10(-6)), diffuse involved margins (p = 0.003), and margins involved with intraductal component (p < 10(-6)) were predictive of LIR. Re-excision for a margin involved with intraductal carcinoma significantly improved local relapse-free survival (p < 0.001).
Conclusions: In cases of IDC, re-excision for a close margin or a focally involved margin had no impact on local relapse-free survival. The decision to perform a surgical re-excision for an involved margin should not be systematic but should take multiple risk factors into consideration, such as patient age or margin diffuse involvement.