[Is preoperative axillary radio-cytology justified after ACOSOG Z001?].

Introduction: Invasive breast cancer without clinical adenopathy (cN0) is currently explored by the sentinel node (GS) technique, except in the case of positive preoperative radio-cytological screening, where axillary curage (CA) remains systematic from the outset. Since the publication of the ACOSOG-Z0011 trial, abstention from CA is possible in patients presenting less than three metastatic GS. As a result, the value of axillary radio-cytological screening is being questioned as it could potentially lead to axillary surgical over-treatment. The objective of this study was to study clinically N0 patients with positive axillary cytology and to compare it to a group of patients with positive GS.

Method: One hundred and forty-seven patients with cN0 pN+ breast cancer treated between 2014 and 2016 were selected retrospectively. Two groups were constituted according to the initial radio-cytological evaluation. A CA was systematically performed.

Results: Thirty-one patients with positive axillary cytology (n=31 vs. n=116) had more metastatic lymph nodes (P=0.01) in the AC, larger (P<0.001), less differentiated (P<0.001) tumours, and shorter recurrence-free survival (P=0.0114). It also appeared that 38.7 % of patients with a positive cytology had at most two metastatic nodes and could, according to the results of ACOSOG, benefit from therapeutic de-escalation.

Conclusion: X-ray cytological screening remains essential in order to select a subgroup of patients with a high lymph node tumour load. Additional studies are necessary in order to be able to offer therapeutic de-escalation to 1/3 of these patients without the risk of under-treatment for the remaining 2/3.