The role of margin status and reexcision in local recurrence following breast conservation surgery

Breast conservation surgery (BCS) results in survival equal to mastectomy for early-stage breast cancer. Ipsilateral breast tumor recurrence (IBTR) after BCS is thought to be related to margin status. At our institution, reexcision is performed only if tumor is at inked margin or with extensive disease close to multiple margins. The purpose of this study was to determine rates of reexcision and recurrences among BCS patients using this policy.

We performed an institutional review board-approved retrospective analysis of BCS patients who underwent surgery between January 2001 and June 2005. We identified patients who had a second breast excision within 8 weeks of the first, and those patients with an IBTR. Clinical and pathologic features of patients' tumors were reviewed.

We identified 543 patients who underwent BCS, 84 patients (15.5 %) underwent reexcision for margin status. The crude IBTR rate was 3.4 %, and the 5-year local recurrence-free survival of the reexcised group was 90.6 % compared with 97.4 % in the non-reexcised group (p = 0.0097). Of the 64 reexcision patients, 6 (9.4 %) had an IBTR versus 12 (2.6 %) of the 459 non-reexcised patients (p = 0.0151).

Our reexcision rate is low compared with other reports. This results from a policy that defines "no tumor on ink" as an adequate margin for BCS, and the use of selective irradiation boosts based on margins assessed by our pathologists. Our local recurrence rate compares favorably with those seen in other studies while minimizing the need for additional operations. A higher IBTR rate after reexcision likely reflects tumor biology.