Reoperative Sentinel Lymph Node Biopsy: Adding Nuance to the Management of Locally Recurrent Breast Cancer

Abstract

Since the pioneering reports of Krag et al. and Giuliano et al. >10 years ago, sentinel lymph node (SLN) biopsy has emerged as a new method for axillary lymph node staging in breast cancer and has become standard care at many institutions in the United States and worldwide. A current meta-analysis of 69 published studies of SLN biopsy validated by a backup axillary lymph node dissection (ALND) confirms an overall success rate of 96%, with the SLN falsely negative in 7.3% of node-positive cases. Observational studies have asked and answered many questions regarding definition, case selection, technique (nuclear medical, surgical, and pathologic), learning curve, and, most importantly, safety. The morbidity of SLN biopsy, although not zero, is less than that of ALND, and axillary local recurrence (LR) after a negative SLN biopsy is both comparable to that of ALND and vanishingly rare, occurring in 0.12% of our own patients at 30 months follow-up. It appears that few false-negative SLN procedures, if any, ever result in axillary LR. Three randomized trials of identical design address the survival equivalence of SLN biopsy and ALND and are almost certain to demonstrate no difference. Finally, two trials, through a physicianand patient-blinded design, promise an answer to the still-controversial subject of prognostic significance in immunohistochemically detected SLN micrometastases. Where do we go from here? Taback et al., in this issue of the Annals, suggest one direction: the application of SLN biopsy in the setting of ipsilateral breast tumor recurrence (IBTR) after breast conservation. Although prior axillary surgery has been anecdotally deemed a contraindication to SLN biopsy, they demonstrate (as we have previously) the feasibility of reoperative SLN biopsy. Among 15 patients (6 with a previous SLN biopsy and 9 with a previous ALND) who developed IBTR, lymphoscintigraphy (LSG) imaged SLNs in 11 (73%). Among 14 patients explored, they identified SLNs in 11 (79%). Their finding that three of four patients with a negative LSG had a previous ALND fits with our observation that the success of reoperative SLN biopsy is inversely related to the number of axillary nodes removed previously. Finally and most importantly, they demonstrate a higher-than-expected rate of lymphatic drainage to nonaxillary sites (including supraclavicular, internal mammary, interpectoral, and contralateral axilla): two of three SLN-positive patients had contralateral axillary disease. We made the same observation in a recent update of our own experience; comparing reoperative SLN biopsy (n = 133) with first-time SLN biopsy (n = 7559), LSG showed nonaxillary drainage in 24% vs. 5% of cases (P < .001; unpublished data). Routine preoperative LSG for SLN biopsy in primary breast cancer is still a matter of debate but may prove particularly useful in the reoperative setting, where prior surgery may have altered the pattern of lymphatic drainage. Their study raises larger issues as well. Over the last 30 years, the management of breast cancer has evolved from an era of clinical detection and a single Received January 24, 2006; accepted February 1, 2006; published online j. Address correspondence and reprint requests to: Hiram S. Cody III, MD; E-mail: codyh@mskcc.org.