Is sentinel lymph node biopsy enough for axillary macrometastasis?

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includes patients with both micro and macrometastasis in sentinel lymph node(s). Early stage breast cancer patients with clinical N0 disease and one or two positive sentinel lymph node(s) are randomized to axillary lymph node dissection (ALND) vs. sentinel lymph node dissection (SLND) alone. At a median follow-up of 6.3 years, both 5-year overall survival (91.8% vs. 92.5%; ALND vs. SLND) and 5-year diseasefree survival (82.2% vs. 83.9%; ALND vs. SLND) are not significantly different between the arms (1, 2). Arguably, Z0011 study is one of the most important practice changing or at least practice questioning randomized study in recent years. The second trial is the International Breast Cancer Study Group (IBCSG) 23-01 study, which has the same patient population of Z0011 but with only one or 2 sentinel micrometastatic lymph node(s) and also the same randomization. In IBCSG 23-01 trial, the 5-year disease-free survival is also not significantly different between the groups (84.4% vs. 87.8%; ALND vs. SLND) (3). IBCSG 23-01 trial not only further strengthens the results of the Z0011 for the omittance of axillary dissection in patients with sentinel micrometastatic lymph node breast cancer but also shows that the quality of life (QOL) of patients could be improved with sentinel biopsy alone in terms of sensory motor neuropathy and lymphedema (3, 4). In the consensus report of Saint Gallen 2013, the policy of avoiding full axillary clearance after one or two positive sentinel nodes is endorsed in situations of conservative surgery and radiotherapy (73%, YES; 21%, NO), including several opinions that the inclusion criteria of the available trial results should be considered (5). Although the Z0011 trial provokes us to omit axillary dissection in patients with cT1-2cN0 disease finally staged at pT1-2pN1(sn), it creates more problems than it solves in terms of radiotherapy fields (1). The radiotherapy directed to axillary basins (i.e., third field nodal radiotherapy) is not allowed in the protocol of the Z0011 trial. However, the details of radiotherapy fields could not be clearly understood from the original report (1). Many radiation oncologists try to irradiate at least some part of the axillary level 1-2 (i.e., high-tangential fields) and even think of using third field (i.e., supraclavicular level 3), particularly for patients with no reasonable systemic treatment option (i.e., triple negative case). Recently, the detail of radiotherapy fields at least for some part of the patients in the Z0011 trial is presented at the San Antonio Breast Cancer Symposium 2013 (6). Detailed radiotherapy records were received for 228 patients only: 104/389 (26.7%) ALND vs. 124/404 (30.7%) SLND. Sixty-one of 104 (59%) patients in ALND arm also received some form of lymphatic radiotherapy [supraclavicular, n=22 (21%), posterior axillary boost n=6 (6%), and high tangents n=33 (32%)]. In the SLND arm, some form of lymphatic radiotherapy was also used for 73 of 124 (59%) patients [supraclavicular n=21 (17%), posterior axillary boost n=12 (10%), and high tangents n=40 (32%)] (6). Although the data of the central radiotherapy review of the entire Z0011 population could not be available currently, approximately 60% of the patients have received some form of lymphatic radiotherapy and 18.9% of them have major protocol violation (i.e., third field nodal radiotherapy is not allowed in the protocol). Thus, regional radiotherapy may contribute to the results that have been obtained from both arms of the Z0011 trial.