Tumor stiffness measured by shear-wave elastography: association with disease-free survival in women with early-stage breast cancer

Abstract

Objective: To determine whether shear-wave elastography (SWE)-measured tumor stiffness is associated with disease-free survival in females with early-stage invasive breast cancer. Methods: This retrospective study included 202 consecutive females (mean age, 52.9 years; range, 25–84 years) with newly diagnosed T1–two breast cancer who underwent preoperative SWE between April 2015 and January 2016. Tumor stiffness was assessed and quantitative SWE features of each breast lesion were obtained by a breast radiologist. Cox proportional hazard models were used to identify associations between SWE features and disease-free survival after adjusting for clinicopathologic factors. Results: Fifteen (7.4%) patients exhibited recurrence after a median follow-up of 56 months. Mean (Emean), minimum, and maximum elasticity values were higher in females with recurrence than in those without recurrence (184.4, 138.3, and 210.5 kPa vs 134.9, 101.7, and 159.8 kPa, respectively; p = 0.005, p = 0.005, and p = 0.012, respectively). Receiver operating characteristics curve analysis for prediction of recurrence showed that Emean yielded the largest area under the curve (0.717) among the quantitative SWE parameters, and the optimal cut-off value was 121.7 kPa. Multivariable Cox proportional hazards analysis revealed that higher Emean (>121.7 kPa) [adjusted hazard ratio (HR), 10.01; 95% CI: 1.31–76.33; p = 0.026] and lymphovascular invasion (adjusted HR, 7.72; 95% CI: 1.74–34.26; p = 0.007) were associated with worse disease-free survival outcomes. Conclusion: Higher SWE-measured Emean was associated with worse disease-free survival in females with early-stage invasive breast cancer. Advances in knowledge: Tumor stiffness assessed with shear-wave elastography might serve as a quantitative imaging biomarker of disease-free survival in females with T1–two breast cancer.