Axillary concordance between superficial and deep sentinel node mapping material injections in breast cancer patients: systematic review and meta-analysis of the literature

It is still unclear whether the deep and superficial lymphatics of the breast always drain into the same nodes and which route best simulates the spread of breast cancer. In the current study, we systematically searched the available literature to find the studies evaluated the sentinel node locations of deep and superficial injections in the same patients simultaneously or serially. We searched SCOPUS, and PUBMED for relevant studies. Patient basis concordance rate was defined as the ratio of patients with at least one identified axillary sentinel node by both deep and superficial injections to all patients with identified axillary sentinel nodes using either methods. Sentinel node basis concordance was defined as the ratio of the number of axillary sentinel nodes identified by both deep and superficial injections to the sum of all identified axillary sentinel nodes using either methods. Pooled sentinel node detection rates were 94 % [92.1–95.5], 91.2 % [87.1–94.1], and 97.2 % [96–98] for superficial, deep, and combined (superficial and deep) injections. Pooled patient basis and sentinel node basis concordance rates were 90 % [86.7–92.4] and 73 % [63.3–80.9]. Pooled false negative rates were 9.1 % [5.9–14], 8.6 % [3.7–18.8], and 6.5 % [3.4–11.9] for superficial, deep, and combined (superficial and deep) injections, respectively. Axillary lymphatic drainage concordance between superficial and deep sentinel node mapping material in breast cancer patients is fairly high and clinically acceptable. However, both injection techniques can complement each other and the combined superficial/deep injection technique seems to be more successful clinically and can decrease the overall false negative rate.