Shear-wave elastography of invasive breast cancer: correlation between quantitative mean elasticity value and immunohistochemical profile

Abstract

To compare the mean elasticity value, as measured by shear-wave elastography (SWE), with immunohistochemical profile of invasive breast cancer. This was an institutional review board-approved retrospective study, with a waiver of informed consent. A total of 166 invasive breast cancers in 152 women undergoing preoperative SWE and surgery were included. Quantitative mean elasticity values in kPa were measured for each lesion by using SWE. Medical records were reviewed to determine palpability, invasive size, lymphovascular invasion, histologic grade, and axillary lymph node status. Based on the immunohistochemical profiles, tumor subtypes were categorized as triple-negative (TN), luminal A and B, or human epidermal growth factor receptor 2-enriched cancer. The mean elasticity value was correlated with clinicopathological features using univariate regression models and multivariate linear regression analysis. Palpability (P < 0.0001), larger size (P = 0.013), lymphovascular invasion (P < 0.0001), higher histologic grade (P < 0.0001), and lymph node involvement (P = 0.018) were significantly associated with the mean elasticity value. For the immunohistochemical profiles and tumor subtypes, the estrogen receptor (P = 0.015), progesterone receptor (P = 0.002), Ki-67 (P = 0.009), and the TN (P = 0.009) tumor subtype were correlated with the mean elasticity value. Multivariate logistic regression analysis showed that the following variables were significantly associated with the mean elasticity value: palpable abnormality, histologic grade, and lymphovascular invasion. No immunohistochemical profile of the cancers was independently correlated with the mean elasticity value. For invasive breast cancers, clinicopathological features of poor prognosis showed higher mean elasticity values than those of good prognosis. However, the immunohistochemical profile showed no independent association with the mean elasticity value.

Use of shear wave elastography to differentiate benign and malignant breast lesions

“…The mean elasticity cutoff value yielding the maximum sum of specificity and sensitivity was 45.70 kPa, whereas Evans (23,24). A higher histological grade was associated with a higher mean stiffness in both cited studies.…”

Practice guideline for the performance of breast ultrasound elastography

“…Because these cancers are usually high-grade, it has been proposed that hard elasticity (a score of 4 or 5 on SE and a maximum elasticity color of red or a maximum elasticity of ≥160 kPa on SWE) could be used to detect cancers among BI-RADS category 3 masses [6-8]. However, upgrading category 3 masses might be controversial, especially in a screening setting, because the malignancy rate of category 3 masses is known to be very low [25], and malignancies detected by screening US are known to be small in size, indicating relatively low elasticity [28-30].…”

“…Recently, the US elastographic features of breast masses have been incorporated into the 2nd edition of the Breast Imaging Reporting and Data System (BI-RADS) US lexicon as associated findings [5]; hence, the use of elastography is expected to increase. In addition, the correlations between the elasticity and histological features of breast cancers are also being studied [6-8]. This article is focused on the role of elastography combined with B-mode US for evaluating breast masses.…”

Immunohistochemical Subtypes of Breast Cancer: Correlation with Clinicopathological and Radiological Factors

“…Therefore, researchers have sought to determine how well imaging findings can reveal the molecular subtype of a tumor, which would improve the potential for preoperatively-planned treatment strategies. Several studies have explored the correlations between various imaging findings, including mammography, US, and magnetic resonance imaging (MRI), and the clinical features based on various histopathologic markers (8, 9, 12, 13, 19-23). …”