Shear Wave Speed of the Lesion in Preoperative Breast Ultrasonography: Association with Disease-free Survival of Patients with Primary Operable Invasive Breast Cancer

Abstract

We aimed to investigate the relationship between shear wave speed (SWS) of the lesion on preoperative breast ultrasonography (US) and disease-free survival of patients with primary operable invasive breast cancer. This retrospective study was approved by our Institutional Review Board. The requirement for informed consent was waived. A total of 195 consecutive newly diagnosed invasive breast cancer patients (age 33-83 years; mean 54.0 years) with preoperative breast US with SWS measurement of the lesion were identified. They underwent surgery between May 2012 and May 2013. SWS was measured at the center and three marginal zones in the main tumors, and the maximum value was used for analyses. For 35 patients who underwent primary systemic therapy (PST), the maximum SWS before PST was used. Cox proportional hazards modeling was used to identify the relationship between clinical-pathologic factors and disease-free survival. Fourteen recurrences occurred at 6-47 months (mean 22.3 months) after surgery. On multivariate analysis, a positive history of PST (hazard ratio [HR] = 4.93; 95% confidence interval [CI]: 1.66, 14.70; P = .004), adjuvant chemotherapy (HR = 3.67; 95% CI: 1.11, 12.1; P = .033), and higher maximum SWS (HR = 1.55; 95% CI: 1.07, 2.23; P = .020) were associated with poorer disease-free survival. Higher maximum SWS on preoperative US, in addition to a positive history of PST and adjuvant chemotherapy, was significantly associated with poorer disease-free survival of patients with invasive breast cancer.