Shear-wave elastography in invasive ductal carcinoma: correlation between quantitative maximum elasticity value and detailed pathological findings

Background Further information is needed regarding whether histopathological characteristics affect breast tumor elasticity. Purpose To determine whether maximum elasticity values vary according to tumor-stroma ratio, dominant stroma type, or presence of fibrosis in invasive breast cancer. Material and Methods This study included 71 patients with invasive ductal carcinoma not otherwise specified (IDC NOS) who underwent breast shear-wave elastography (SWE). Maximum elasticity (E-max) values were retrospectively correlated with pathological findings that included tumor-stroma ratio, dominant stroma type (collagen, fibroblast, lymphocyte), and fibrosis. Multiple linear regression analysis was performed to determine variables independently associated with E-max. Results High histologic grade was significantly correlated with higher E-max (P=0.042). Estrogen receptor and progesterone receptor expression negatively correlated with high elasticity values (P=0.013 and P=0.03, respectively). Breast cancers that exhibited higher cellularity demonstrated a greater level of stiffness that was not statistically significant (=0.153; P=0.193). While dominant stroma type and fibrosis did not affect E-max (P=0.197 and P=0.598, respectively), lesion size was significantly associated with E-max (=0.474, P<0.001). On multivariate analysis, only lesion size was significantly associated with E-max (P<0.001). Conclusion The composition of tumors did not affect their E-max.