Prediction of high nodal burden with ultrasound and magnetic resonance imaging in clinically node-negative breast cancer patients

Abstract

BackgroundAlthough the role of axillary imaging has been redirected for predicting high nodal burden rather than predicting nodal metastases since ACOSOG Z1011 trial, it remains unclear whether and how axillary lymph node (ALN) characteristics predicts high nodal burden. Our study was aimed to evaluate the predictive value of imaging characteristics of ALNs at ultrasound and magnetic resonance imaging (MRI) for prediction of high nodal burden (≥3 metastatic ALNs) in clinically node-negative breast cancer patients.MethodsClinicopathological and imaging characteristics were evaluated in patients with ultrasound (n = 312) and MRI (n = 256). Imaging characteristics include number of suspicious ALNs and cortical morphologic changes (grade 1, cortical thickness < 2 mm; grade 2, 2–5 mm; grade 3, ≥5 mm or fatty hilum loss). Odds ratios (ORs) were calculated using multivariate analysis.ResultsFor ultrasound, higher (≥2) T stage (OR = 5.65, P = .005), higher number of suspicious ALNs (2 suspicious ALNs, OR = 6.52, P = .019; ≥ 3 suspicious ALNs, OR = 21.08, P = .005), and grade 3 of cortical morphologic changes (OR = 9.85, P = .023) independently associated with high nodal burden. For MRI, higher (≥2) T stage (OR = 5.17, P = .011) and higher number of suspicious ALNs (2 suspicious ALNs, OR = 69.00, P = .001; ≥ 3 suspicious ALNs, OR = 93.55, P < .001) were independently associated with high nodal burden. Among patients with 2 suspicious ALNs, those with grade 3 cortical morphologic change at ultrasound had a higher rate of high nodal burden than those with grade 2 (60.0% [3/5] vs. 25.0% [2/8]).ConclusionsA higher number of suspicious ALNs is an independent predictor for high nodal burden. Further stratification can be achieved by incorporating assessment of ultrasound-based cortical morphologic changes.

Can We Identify or Exclude Extensive Axillary Nodal Involvement in Breast Cancer Patients Preoperatively?

“…Further, the presence of extensive nodal involvement is significantly associated with the number of sonographically suspicious nodes in these studies [12, 17, 18, 21, 25–31]. For instance, Kim et al [18] showed that the percentage of patients with ≥3 positive nodes was 3.1% vs. 38.5% vs. 62.5% in case of ≤1, 2, or ≥3 sonographically suspicious nodes ( P < 0.001). In multivariate analysis, the odds ratios for ≥3 positive nodes were significantly increased when two suspicious nodes were seen (OR 6.52, 95% CI 1.36–31.28) and when more than two suspicious nodes were seen (OR 21.08, 95% CI 2.57–172.86) [18].…”

“…These studies concluded that the mean number of positive axillary nodes is significantly higher amongst patients with their positive nodes identified by AxUS than by SNB [14, 19, 24]. Further, the presence of extensive nodal involvement is significantly associated with the number of sonographically suspicious nodes in these studies [12, 17, 18, 21, 25–31]. For instance, Kim et al [18] showed that the percentage of patients with ≥3 positive nodes was 3.1% vs. 38.5% vs. 62.5% in case of ≤1, 2, or ≥3 sonographically suspicious nodes ( P < 0.001).…”

“…For instance, Kim et al [18] showed that the percentage of patients with ≥3 positive nodes was 3.1% vs. 38.5% vs. 62.5% in case of ≤1, 2, or ≥3 sonographically suspicious nodes ( P < 0.001). In multivariate analysis, the odds ratios for ≥3 positive nodes were significantly increased when two suspicious nodes were seen (OR 6.52, 95% CI 1.36–31.28) and when more than two suspicious nodes were seen (OR 21.08, 95% CI 2.57–172.86) [18]. Farrell et al [25] showed that the mean number of histologically positive nodes was significantly higher if more than two suspicious nodes were detected sonographically compared to two or only one (10.1 vs. 7.5 vs. 5.2) [25].…”

“…All studies concluded that increased cortical thickness was an independent predictor of extensive nodal involvement [10, 18, 28, 32, 33]. The most optimal cutoff value to discriminate between limited and extensive nodal involvement ranges between 3.0 and 5.0 millimeters in these studies [10, 18, 28]. For instance, Lim et al [33] used a cutoff point of maximum cortical thickness of 4.0 millimeters.…”

“…Three studies defined extensive nodal involvement as ≥3 positive nodes. Two of these three studies performed dynamic contrast-enhanced MRI (DCE-MRI) with gadolinium-based contrast agents [17, 18]. One of these studies performed unenhanced MRI [16].…”