Omission of axillary dissection according to ACOSOG Z0011: impact on adjuvant treatment recommendations.

OBJECTIVE: A recent, randomized trial (ACOSOG Z0011) has demonstrated that omission of completion axillary lymph node dissection (ALND) in patients with one or two sentinel lymph node (SLN) metastases treated with breast conserving therapy (BCT) does not have a negative impact on survival. This study evaluates the impact of omitting ALND on adjuvant treatment recommendations.

METHODS: Performing a search of our clinical database, we identified patients meeting the main inclusion and exclusion criteria of ACOSOG Z0011 treated at the University of Heidelberg Breast Center. We performed blinded mock interdisciplinary tumor boards based on patient and tumor characteristics as well as (1) SLN information or (2) final nodal status after ALND. Differences between treatment recommendations were noted and analyzed.

RESULTS: A total of 132 patients were included; 80.3 % of these had one and 19.7 % had two metastatic sentinel nodes with a rate of micrometastases only of 19.7 %, and 39.7 % of patients had additional nonsentinel node metastases upon ALND. Overall, there was a change in adjuvant chemotherapy in 18.2 % of cases. Treatment recommendations based on ALND lead to a more aggressive therapy in 16.6 % of cases, all of them with additional metastatic nonsentinel nodes. Chemotherapy was not recommended in only two cases (1.5 %) based on ALND. Based on ALND, irradiation of the supraclavicular and infraclavicular nodes was added in 5.3 % of patients.

CONCLUSIONS: Completion ALND for patients with one or two metastatic sentinel nodes in pT1-2 cN0 PBC treated with BCT does have a relevant impact on adjuvant treatment. This should be considered in shared decision making.