Breast MRI Biomarkers: Edema Score and Elastography Stiffness Show Clinical Utility

Two MRI-based biomarkers are providing new tools for breast imaging assessment. The Breast Edema Score (BES) offers a noninvasive means of evaluating tumor aggressiveness in invasive breast cancer, while magnetic resonance elastography (MRE)-derived stiffness correlates closely with CT attenuation for quantitative breast tissue characterization.

The Breast Edema Score serves as an essential MRI-based tool for radiologists to evaluate tumor severity. By analyzing fluid accumulation patterns, doctors can gain critical insights into the biological behavior of invasive breast cancer. Consequently, this noninvasive marker assists in risk stratification before initiating complex treatment protocols. Moreover, identifying high-risk features early allows for more personalized oncology care. A study published in European Radiology examined the breast edema score as a biomarker of tumor aggressiveness and its predictive value for neoadjuvant chemotherapy response.

Radiologists classify breast edema based on its anatomical distribution, ranging from no edema to subcutaneous involvement. The score typically ranges from Grade 1, which represents no edema, to Grade 4, indicating extensive subcutaneous edema. Higher scores typically correlate with aggressive markers such as larger tumor size and higher histological grade. Furthermore, researchers found a significant association between edema and axillary lymph node metastasis. Because of these links, the presence of edema often indicates a more challenging clinical course. However, recent evidence suggests that the score does not reliably predict responses to neoadjuvant chemotherapy.

Although the score highlights tumor aggressiveness, its inability to predict chemotherapy response remains a point of clinical debate. Clinicians should use BES primarily for phenotyping tumors and assessing the likelihood of lymphovascular invasion. Additionally, non-luminal subtypes like triple-negative breast cancer frequently exhibit higher edema levels. Therefore, integrating this scoring system into routine MRI reports provides a clearer picture of the disease state. This data-driven approach empowers medical teams to make informed decisions regarding surgical margins and overall prognosis.

In a separate study published in Medical Science Monitor, researchers evaluated the relationship between MRE stiffness and CT attenuation in normal breast tissues. In this single-center study, 48 women (aged 29-56 years) who underwent breast magnetic resonance imaging (MRI) with routine 3T MRE and non-contrast chest CT within ±1 month were included. MRE was performed using a 3T scanner with a 19-cm internal pneumatic driver. The corresponding CT attenuation values were measured from the matched parenchymal regions.

MRE stiffness correlated strongly with CT attenuation (r=0.834, P<0.001). The regression model (kPa=2.402+0.009·HU+0.005·Age) explained 70.1% of the stiffness variance. Fibroglandular tissue showed higher stiffness (2.95±0.43 kPa) and HU (34.6±10.8) than fatty tissue (1.85±0.32 kPa and -89.7±17.3 HU, respectively; P<0.001). The reference stiffness ranges were 2.17-3.77 kPa for fibroglandular and 1.30-2.44 kPa for fatty parenchyma.

The study concluded that breast parenchymal stiffness measured using 3T MRE correlates closely with CT attenuation, confirming that both parameters reflect complementary aspects of tissue density. These findings support MRE as a reliable non-invasive biomarker for quantitative breast tissue characterization.