BACKGROUND: If treatment of the axilla is indicated in @entity1 with @entity0 who have a positive sentinel node, axillary lymph node dissection is the present standard. Although axillary lymph node dissection provides excellent regional control, it is associated with harmful side-effects. We aimed to assess whether axillary radiotherapy provides comparable regional control with fewer side-effects. METHODS: @entity1 with T1-2 primary @entity0 and no palpable @entity3329 were enrolled in the randomised, multicentre, open-label, phase 3 non-inferiority EORTC 10981-22023 AMAROS trial. @entity1 were randomly assigned (1:1) by a computer-generated allocation schedule to receive either axillary lymph node dissection or axillary radiotherapy in case of a positive sentinel node, stratified by institution. The primary endpoint was non-inferiority of 5-year axillary recurrence, considered to be not more than 4% for the axillary radiotherapy group compared with an expected 2% in the axillary lymph node dissection group. Analyses were by intention to treat and per protocol. The AMAROS trial is registered with ClinicalTrials.gov, number NCT00014612. FINDINGS: Between Feb 19, 2001, and April 29, 2010, 4823 @entity1 were enrolled at 34 centres from nine European countries, of whom 4806 were eligible for randomisation. 2402 @entity1 were randomly assigned to receive axillary lymph node dissection and 2404 to receive axillary radiotherapy. Of the 1425 @entity1 with a positive sentinel node, 744 had been randomly assigned to axillary lymph node dissection and 681 to axillary radiotherapy; these @entity1 constituted the intention-to-treat population. Median follow-up was 6  1 years (IQR 4  1-8  0) for the @entity1 with positive sentinel lymph nodes. In the axillary lymph node dissection group, 220 (33%) of 672 @entity1 who underwent axillary lymph node dissection had additional positive nodes. Axillary recurrence occurred in four of 744 @entity1 in the axillary lymph node dissection group and seven of 681 in the axillary radiotherapy group. 5-year axillary recurrence was 0  43% (95% CI 0  00-0  92) after axillary lymph node dissection versus 1  19% (0  31-2  08) after axillary radiotherapy. The planned non-inferiority test was underpowered because of the low number of events. The one-sided 95% CI for the underpowered non-inferiority test on the hazard ratio was 0  00-5  27, with a non-inferiority margin of 2. Lymphoedema in the ipsilateral arm was noted significantly more often after axillary lymph node dissection than after axillary radiotherapy at 1 year, 3 years, and 5 years. INTERPRETATION: Axillary lymph node dissection and axillary radiotherapy after a positive sentinel node provide excellent and comparable axillary control for @entity1 with T1-2 primary @entity0 and no palpable @entity3329 . Axillary radiotherapy results in significantly less morbidity. FUNDING: EORTC Charitable Trust.

Radiotherapy or surgery of the axilla after a positive sentinel node in XXXX (EORTC 10981-22023 AMAROS): a randomised, multicentre, open-label, phase 3 non-inferiority trial.

@entity1 :: ('9606', 'Species') :: ['patients', 'Patients'] @entity3329 :: ('MESH:D008206', 'Disease') :: ['lymphadenopathy'] @entity0 :: ('MESH:D001943', 'Disease') :: ['breast cancer']
@entity0 :: (MESH:D001943,Disease) :: ['breast cancer']
