Reoperative sentinel lymph node biopsy: a new frontier in the management of ipsilateral breast tumor recurrence.

BACKGROUND

Breast conservation therapy (BCT) with sentinel lymph node (SLN) biopsy is a well-established standard of care for primary operable breast cancer; 5-10% of BCT patients will develop local recurrence (LR). The question then arises: How best to manage the axilla in the setting of LR after previous BCT and SLN biopsy or axillary dissection (ALND)?

METHODS

Between 9/96 and 12/04, 117 reoperative SLN were performed for LR after BCT and either SLN biopsy or ALND more than 6 months previously. Because of wide variation in the number of nodes removed at the initial procedure, validation by backup ALND was not feasible in all cases.

RESULTS

Reoperative SLN was successful in 64/117 (55%) patients. SLNs were identified by isotope and dye in 28/64 (44%); isotope only in 29/64 (45%); dye only in 4/64 (6%); 3/64 (5%) unknown. Positive reoperative SLN were found in 10/64 (16%) successful cases. Among 54/64 (84%) patients with negative reoperative SLNs, 23 (43%) had additional non-SLN removed concurrently: these were negative in 21/23 cases (91%). In 2/23 (9%), reoperative SLN were falsely negative: one with a positive intramammary node, and the other with a positive non-SLN palpated at surgery. Success of reoperative SLN was inversely related to number of nodes removed previously, and was more likely to be successful after a previous SLN biopsy than a previous ALND (74% vs. 38%, P = 0.0002). Non-axillary drainage was identified by lymphoscintigraphy significantly more often in reoperative SLN than in primary SLN biopsy (30% vs. 6%, P < 0.0001). There were no local or axillary recurrences at a mean follow up of 2.2 years; 6 patients developed systemic recurrence.

CONCLUSIONS

Reoperative SLN biopsy is feasible in the setting of LR after previous BCT/axillary surgery and deserves further study in this increasingly common clinical scenario. The added benefit of lymphoscintigraphy in identifying sites of non-axillary drainage may be greater in the setting of reoperative SLN than for the initial SLN procedure.