Extracapsular extension in the positive sentinel lymph node: a marker of poor prognosis in cT1-2N0 breast cancer patients?

Abstract

Objective

This study aims to evaluate whether extracapsular extension (ECE) in the sentinel lymph node (SLN) is associated with involvement of ≥ 4 lymph node metastases at completion axillary lymph node dissection (ALND) and the effect on 5-year disease-free survival (DFS) and 10-year overall survival (OS).

Summary background data

ECE in a SLN is usually a contraindication for omitting completion ALND in cT1-2N0 breast cancer patients treated with breast-conserving therapy and 1–2 positive SLN(s).

Methods

All cT1-2N0 breast cancer patients with 1–3 positive SLN(s) who underwent ALND between 2005 and 2008 were selected from the Netherlands Cancer Registry. Logistic regression analysis was used to determine the association between ECE and ≥ 4 lymph node metastases. Five-year DFS and 10-year OS were analyzed using Kaplan–Meier survival analysis. Cox regression analysis was performed to correct for other prognostic factors.

Results

A total of 3502 patients were included. Information on ECE was available for 2111 (60.3%) patients, consisting of 741 (35.1%) patients with and 1370 (64.9%) without ECE. The incidence of ≥ 4 lymph node metastases was 116 (15.7%) in the ECE group vs. 80 (5.8%) in the group without ECE (p < 0.001). Five-year DFS rate was 86.4% in the ECE group compared to 88.8% in the group without ECE (p = 0.085). 10-year OS rate was 78.6% compared to 83.0% (p = 0.018), respectively. Cox regression analysis showed that ECE was not an independent prognostic factor for both DFS and OS.

Conclusions

ECE was significantly associated with involvement of ≥ 4 lymph node metastases in the completion ALND group. ECE was not an independent prognostic factor for both DFS and OS.

http://bit.ly/2F75khf