Tumor stiffness measured by quantitative and qualitative shear wave elastography of breast cancer

Abstract

Objective: To correlate clinicoradiologic and pathological features of breast cancer with quantitative and qualitative shear wave elastographic parameters.

Methods: 82 breast cancers in 75 patients examined by B-mode ultrasound and shear wave elastography (SWE) were included. SWE parameters including quantitative factors [maximum elasticity (E_max), mean elasticity (E_mean), elasticity ratio (E_ratio) and standard deviation (SD)] and qualitative factor (color pattern) were correlated with clinicoradiologic and pathological features using univariate and multivariate linear regression analyses.

Results: Presence of symptoms and larger tumor size on ultrasound were significantly associated with higher E_max, E_mean, E_ratio, and SD (all p < 0.05) on univariate analysis. Older age was significantly correlated with higher E_max and E_mean (p = 0.026, 0.018). Lymphovascular invasion and larger pathologic size were significantly associated with higher E_max (p = 0.036, 0.043) and SD (p < 0.001, 0.019). No immunohistochemical biomarkers were significantly correlated with SWE parameters. There was no significant correlation between color pattern and any variable. Multivariate logistic regression analysis showed that the symptom, tumor size on ultrasound and lymphovascular invasion were independent factors that influenced the SWE values.

Conclusion: Tumor stiffness as measured by SWE and B-mode ultrasound could help predict cancer prognosis. Advances in knowledge: Clinicoradiologic factors had correlation with quantitative and qualitative SWE parameters. Using SWE parameters and B-mode ultrasound, we can predict breast cancer prognosis.

Figure 1.

A 75-year-old female with a 26.5 mm, Grade 3, intraductal carcinoma in the left breast. SWE color map (top) shows that the colored area was heterogeneously present in the interior of the mass (Pattern 4), and the lesion had high stiffness (E_max, 204.6 kPa; E_mean, 168.2 kPa; E_ratio, 9.8; SD, 39.2 kPa). On pathology, the cancer showed lymphovascular invasion, positive ER and PR, negative HER2, and positive Ki-67. ER, estrogen receptor; HER2, human epidermal growth factor receptor 2; PR, progesterone receptor; SD, standard deviation; SWE, shear wave elastography.

Figure 2.

A 51-year-old female with a 4 mm, Grade 1, ductal carcinoma in situ in the left breast. B-mode ultrasound (bottom) shows that mass has irregular shape and non-circumscribed margin. SWE color map (top) shows that blue color around the lesion continues vertically on the cutaneous side (Pattern 2) and low SWE values (E_max, 33.5 kPa; E_mean, 27.0 kPa; E_ratio, 1.4; SD, 3.7 kPa). On pathology, the cancer showed no lymphovascular invasion, negative ER, negative PR, negative HER2, and negative Ki-67.