Regional nodal recurrence in breast cancer patients treated with conservative surgery and radiation therapy (BCS+RT).

PURPOSE: To review regional nodal (RN) management and identify predictors of RN relapse in patients treated with breast conserving surgery and radiation therapy (BCS+RT).

METHODS AND MATERIALS: Patients with Stage I and II breast cancer (N = 1920) underwent BCS+RT from 1973 to 2003. Patients undergoing RN were treated with a median dose of 46 Gy. Patients undergoing axillary dissection (AXD, N = 1330) were treated to the breast alone if node-negative (N = 984), and to the breast and supraclavicular fossa if node-positive (N = 346). Patients who did not undergo AXD (N = 590) were treated with RT to the supraclavicular fossa and axilla. Sentinel node biopsy (SNB) was performed on 126 patients. SN-negative patients (N = 110) were treated with tangents only. There were 16 SN-positive patients who did not undergo complete AXD and were treated with RT.

RESULTS: As of September 2005, there have been 36 RN relapses for an actuarial nodal control rate (NCR) of 98% at 10 years. There was no difference in NCR between those undergoing AXD (NCR = 97.4%) and those receiving RT without AXD (NCR = 97.9%). In multivariate analysis, young age, non-Caucasian race, and pathologic nodal status correlated with increased risk of nodal relapse. Of the 126 patients undergoing SNB, there was only 1 nodal recurrence. None of the 16 SN-positive patients treated with RT without AXD had nodal failure.

CONCLUSIONS: In patients undergoing BCS+RT, both regional nodal irradiation and AXD (including SNB) resulted in equally high rates of regional nodal control. Nodal RT may also be an effective treatment for SN-positive patients.