Analysis of factors related to N2- or N3-stage breast cancer associated with 1-2 positive sentinel lymph nodes in Chinese patients.

Abstract

BackgroundThis study aims to determine the incidence of N2- or N3-stage disease in a cohort of patients with T1–T2 invasive breast cancer and one or two positive sentinel lymph nodes (SLNs), and identify the risk factors for N2/3 disease in this cohort.MethodsThe present study involved 298 patients with T1–T2 tumors who underwent SLN biopsy and were found to have one or two metastatic SLNs. The proportion of patients with N2/3 disease was calculated in the whole cohort, and in the T1 and T2 subgroups. Furthermore, univariate and multivariate analyses were used to identify the risk factors for N2/3 disease in the cohort.ResultsThe final N stage, as determined by the postoperative pathological examination, was N1 for 250 (83.9%) patients, and N2 or N3 for 48 (16.1%) patients (11.41% had clinical N2 disease, while 4.70% had clinical N3 disease). Among the 156 patients with T1 tumors, 17 (10.9%) patients had N2/3 disease, while for the 142 patients with T2 tumors, 31 (21.8%) patients had N2/3 disease. T2 stage, lymphovascular invasion, and the number of positive SLNs were independent predictors of N2/3 disease in the cohort (P<0.05).ConclusionsN2/3 lymph node metastasis occurs in patients with T1–T2 breast cancer, and one or two positive SLNs, particularly in patients with T2 tumors. The rate of N2/3 disease is not negligible. T2 stage, lymphovascular invasion, and the number of positive SLNs were independent predictors of N2/3 disease in the present patient population.