The clinical utility of assessment of the axilla in women with suspicious screen detected breast lesions in the post Z0011 era

Abstract

Axillary ultrasound (AUS) and biopsy are now part of the preoperative assessment of breast cancer based on the assumption that any nodal disease is an indication for axillary clearance (AC). The Z0011 trial erodes this assumption. We applied Z0011 eligibility criteria to patients with screen detected cancers and positive axillary assessment to determine the relevance of AUS to contemporary practice. Women screened between 1/1/2012 and 30/6/2013 and assessed for lesions with highly suspicious imaging features are included. We analysed demographic and assessment data and ascertained the final histopathology with particular reference to axillary nodal status. Among 449 lesions, AUS was recorded in 303 lesions (67.5 %). 290 (96 %) were carcinomas, 30.3 % with nodal disease. AUS was abnormal in 46 (15.9 %). AUS had a sensitivity of 39.8 %, specificity 94.6 %, positive predictive value (PPV) 79.2 % and negative predictive value (NPV) 78.1 %. Axillary FNAB was positive in 27 women, suspicious in two, benign in 16 and not performed in one. In one FNA positive case, the lesion was a nodular breast primary in the axillary tail in a multifocal breast cancer. Combining AUS and FNAB, the sensitivity was 76.5 %, specificity 90.9 %, PPV 96.3 % and NPV 55.6 %. Applying the Z0011 inclusion criteria, 24 of the 27 (88.9 %) women with abnormal AUS and positive FNA were ineligible for Z0011-based management. Of three women eligible for Z0011, one proceeded to AC after SN biopsy, leaving only two women (7.4 %) who might have been considered for SN only management had it not been for the results of the axillary assessment. Among women with negative AUS, nodal metastasis was demonstrated in 21.7 %, 86.8 % of these women having only 1-2 positive nodes. Abnormal AUS and FNA preferentially identify candidates for AC. Negative AUS predicts negative or low nodal burden. Axillary assessment streamlines care.