Imaging and pathology features to predict axillary tumor load in breast cancer.

Abstract

We investigated if imaging and pathology features could help to identify a high axillary tumor burden (ATB) in breast cancer patients, in order to individualize decisions on axillary lymph node (ALN) dissection (ALND). We retrospectively analyzed patients primarily treated with surgery in our unit between 2011 and 2014. We divided the patients in two groups: low ATB (LATB) if ≤ 2 ALN were infiltrated and high ATB (HATB) if > 2 ALN were infiltrated. Data of 105 patients was included in the study. Axillary ultrasound (AUS) features associated with HATB were any sign of ALN infiltration (76 vs 24%, P = 0.027) and > 2 suspicious ALNs (73% vs 27%, P = 0.018); however, when AUS revealed ≤ 2 suspicious ALNs, 39% of these patients had HATB. Any sign of ALN infiltration on magnetic resonance imaging was associated with HATB (48% vs 52%, P = 0.031). Positive preoperative ALN cytology or biopsy was associated with HATB (53% vs 47%, P = 0.008), while p53 positivity (80% vs 20%) and high histological grade (68% vs. 32%) correlated with LATB (P = 0.05 and P = 0.02, respectively). In multivariate analysis, only positive preoperative ALN cytology or biopsy was associated with HATB (P = 0.038). AUS was useful for detecting HATB but was not as effective in patients with LATB. Proving axillary infiltration with AUS-directed cytology or biopsy is the most effective method to predict HATB.