Estudo do impacto prognóstico da medida da extensão extracapsular em linfonodos axilares metastáticos de pacientes com câncer de mama: associação com parâmetros clínico- patológicos e evolução da doença

Abstract

Extracapsular extension (ECE) of nodal axillary metastasis is associated with worse outcome in breast cancer (BC) patients, while the size of extracapsular extension in the sentinel lymph node has been correlated with nodal tumor burden at axillary lymph node dissection (ALND). However, the prognostic value of ECE extent remains unclear. Our study analyzed the association of ECE size with clinicopathological criteria and survival in breast cancer (BC). Patients diagnosed with node-positive BC from 1994-2014 were selected at a university hospital. Chart review documented clinicopathological data. Original H&E slides were re-evaluated to determine tumor histologic type/grade, presence, size and area of ECE (largest size perpendicular to the node capsule, PECE; size measured transversely to the capsule, TECE; area, AECE). Comparisons were made by ECE extent (<2mm versus ≥2mm) and area. Our database quest identified 1,238 node-positive BC patients, 632 were excluded because of unavailable medical records, leaving 605 for evaluation. ECE was observed in 393 (65%) cases, either in the sentinel and/or non-sentinel nodes. When ECE was present, patients had shorter overall and disease-free survival (DFS; p<0.01). Compared to <2mm, PECE ≥2mm was significantly associated with pre-menopause, high histologic grade, N3 disease, higher number of ECE foci at ALND, axillary tumor implants and poorer DFS (p=0.01); whereas TECE ≥2mm and AECE ≥4mm² correlated with N3 disease, a higher number of ECE foci, axillary tumor implants, advanced cancer stage, recurrence (for TECE only) and shorter DFS (p<0.01). Results were similar when applying median ECE extent instead of the 2mm cut-off. Also, axillary tumor implants/emboli correlated with worse rates of overall survival and DFS. Our findings confirm that ECE is associated with worse outcome in BC. ECE extent/area, axillary tumor implants and neoplastic emboli correlate with a more aggressive tumor phenotype, nodal tumor burden, recurrence and poorer DFS in node-positive breast cancer patients.