Risk Stratification For Axillary Lymph Node Metastases in Breast Cancer Patients What Clinicopathological and Radiological Factors of Primary Breast Cancer Can Predict Preoperatively Axillary Lymph Node Metastases?

This study was to investigate clinicopathological features including immunohistochemical subtype and radiological factors of primary breast cancer to predict axillary lymph node metastasis (ALNM) and preoperative risk stratification. From June 2004 to May 2014, 369 breast cancer patients ( mean age, 54.7 years; range, 29-82 years) who underwent surgical axillary node sampling were included. Two radiologists retrospectively reviewed clinicopathological features, initial mammography, and initial breast ultrasonography ( US). Univariate and multivariate logistic regression analyses were used to evaluate associations between ALNM and variables. Odds ratio with 95% confidence interval and risk of ALNM were calculated. Among 369 patients, 117 (31.7%) had ALNM and 252 (68.3%) had no ALNM revealed surgically. On multivariate analysis, four factors showed positive association with ALNM: the presence of symptoms (P < 0.001), triple-negative breast cancer subtype ( P = 0.001), mass size on US (> 10 mm, P < 0.001), and Breast Imaging Reporting and Data System category on US (>= 4c, P < 0.001). The significant risk of ALNM was particularly seen in patients with two or more factors ( 2, P = 0.013; 3, P < 0.001; 4, P < 0.001). The estimated risks of ALNM increased in patients with two, three, and four factors with odds ratios of 5.5, 14.3, and 60.0, respectively. The presence of symptoms, triple-negative breast cancer subtype, larger size mass on US (> 10 mm), and higher Breast Imaging Reporting and Data System category on US (>= 4c) were positively associated with ALNM. Radiologically, US findings are significant factors that can affect the decision making process regarding ALNM. Based on risk stratification, the possibility of ALNM can be better predicted if 2 or more associated factors existed preoperatively.