Is-it worthwhile to give up axillary clearance (AC) after Sentinel Node (SN) micrometastasis

There is currently a large debate about this question. A meta-analysis indicatesthat, globally after positive SN, axillary clearance is positive in 30% of cases.But for macrometastasis, the risk is about 50% (45-79), for micrometastasisabout 18% (13-23) and for isolated cells 12% (9.5-15.7) [1] .The option to give-up AC after SN micrometastasis leads to 3 main questions:· Does this omission have any impact on the axillary recurrence rate · Does it have any impact on overall survival (OS) and recurrence freesurvival (RFS) · Could this omission induce undertreatment or even overtreatment Regarding the risk of axillary recurrence, there is very good news. As in allseries, the rate is very low after SNB alone: 0.7% at 8 years and 0.8% at 10years in the two largest studies [2]. But the expected rate is 8 to 10%,corresponding to the false negative rate of the technique. This very low rate ofaxillary recurrence is related to the benefit of radiotherapy and adjuvanttreatments, and maybe some spontaneous regression. Consequently, the realproven failure rate of SNB is very low, less than 1% at 10 years, and this isexactly the same results observed after axillary clearance!