Predictors of sentinel lymph node metastasis in Chinese women with clinical T1-T2 N0 breast cancer and a normal axillary ultrasound

Abstract

Background The clinicopathological predictors of sentinel lymph node (SLN) metastasis in clinical T1-T2 N0 (cT1-T2 N0) patients with a normal axillary ultrasound (AUS) are unclear. Purpose To assess the association between clinicopathological characteristics of a primary tumor and SLN metastasis in cT1-T2 N0 patients with a normal AUS. Material and Methods Patients who were diagnosed with cT1-T2 N0 invasive breast cancer and who obtained normal AUS results between October 2016 and September 2018 in a single hospital were included. Clinicopathological data were collected to explore the predictors of SLN metastasis using a multivariate logistic regression model. Results SLN metastasis occurred in 26 patients (18.4%) among 141 AUS-normal patients, of which 24 cases (17.0%) had one or two nodal involvements. In the univariate analysis, tumor location, estrogen receptor (ER) status, progesterone receptor (PR) status, and lymphovascular invasion (LVI) were significantly associated with SLN metastasis ( P < 0.05). The multivariate analysis showed that tumor location in the upper outer quadrant (odds ratio [OR] = 4.49, 95% confidence interval [CI] = 1.63–12.37; P = 0.004), positive PR status (OR = 13.35, 95% CI = 1.60–111.39; P = 0.017), and positive LVI (OR = 8.66, 95% CI = 2.20–34.18; P = 0.002) were independent high-risk factors for SLN metastasis. The area under the receiver operating characteristic curve of the regression model was 0.787 (95% CI = 0.694–0.881; P < 0.001). Conclusion Tumor location in the upper outer quadrant, positive PR, and LVI status were found to be significantly high-risk factors for SLN metastasis among cT1-T2 N0 breast cancer patients with a normal AUS result.