Is my patient an appropriate candidate for sentinel node biopsy? Less axillary surgery, for the right patients. Critical review and grades of recommendation

Introduction While general conclusions of historical trials are widely recognized, the nuances regarding precise indications of Sentinel Node Biopsy (SNB) in breast cancer in complex clinical scenarios often remain a source of debate and require further elucidation. Methods Two reviewers (JFB and GNM) independently searched electronic databases for studies including SNB as the main intervention. Filters were applied to retrieve only clinical trials (randomized or experimental non-randomized); non-oncological outcomes were excluded. The selected studies were considered to construct a narrative review focused on inclusion criteria and survival outcomes, followed by recommendations. Results Fourteen (n = 14) trials were selected, including eleven (n = 11) randomized trials for upfront surgery, and three (n = 3) single-group clinical trials for surgery following neoadjuvant therapy. All trials for upfront surgery provided long-term survival data for SNB, that was equivalent or non-inferior to axillary dissection, in tumors without palpable adenopathy (caution for larger T3 and T4 tumors) - Grade of recommendation: A. In tumors up to 5 cm, complete axillary dissection is not necessary if up to two sentinel nodes are positive for macrometastasis, and radiation therapy is planned - Grade of recommendation: A. If there are more than two sentinel nodes positive for macrometastasis, or a positive node other than the sentinel one, complete axillary dissection is recommended - Grade of recommendation: A. Following neoadjuvant chemotherapy, considering 10% as an acceptable false negative rate, SNB might be offered for cN0 patients who have remained negative, and for cN1 (caution for cN2) patients become clinically negative; complete axillary dissection might not be necessary if at least two sentinel lymph nodes are retrieved, and there is no residual disease - Grade of recommendation: B. Conclusion SNB can be performed in most cases of clinically negative nodes. After neoadjuvant chemotherapy, SNB is feasible and may have acceptable performance for cN0 and cN1 tumors, although prospective survival data is still awaited.