Shear wave elastography of the breast—Immunohistopathology and molecular subtype comparisons

Abstract Introduction This study evaluated the shear wave elastography (SWE) in kilopascals (kPa) and metres per second (m/s) of immunohistochemical (IHC) factors, molecular subtypes, and the relationship between Kiel‐67 (Ki67) and IHC factors to explore their prognostic significance in malignant breast cancer. Methods This single‐centre study included 303 patients with 405 solid breast lesions, biopsied and examined using B‐mode ultrasound and SWE. Elastography mean (Emean), maximum (Emax), and ratio (Eratio) variables in kPa and m/s were calculated for each lesion. Results Among 405 samples, 114 malignant lesions were identified. In IHC comparisons, only the E ratio (m/s) showed a significant difference, with Ki67 high significantly greater than Ki67 low ( p = 0.016). Molecular subtype comparisons using kPa and m/s values revealed significant differences in Emean and Emax ( p < 0.05), with HER2+ subtypes showing the highest values. Correlation analyses showed a significant relationship between Ki67 and molecular subtypes for Eratio in both kPa and m/s ( p < 0.05). Triple‐negative cytokeratin (CK5/6) positive was significantly greater than CK5/6 negative for Eratio in kPa (14.1 ± 3.9 vs. 7.9 ± 0.7, p = 0.029) and m/s (3.7 ± 0.5 vs. 2.8 ± 0.4, p = 0.021). Conclusion Both kPa and m/s SWE variables identify similar yet slightly different results for prognostic IHC factors and molecular subtypes. Examining both kPa and m/s SWE variables may be useful as a non‐invasive method for predicting IHC factors and molecular subtypes to characterise breast lesions before biopsy or surgery.