Natalie N. Clements

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.

Introduction: This study aimed to compare shear wave elastography (SWE) of benign and malignant breast lesions, evaluate the sensitivity and specificity of previously suggested thresholds for identifying malignant breast lesions, and compare SWE measures across histopathological type and grade.Methods: This single‐centre study included 303 patients, and 405 solid breast lesions were biopsied and evaluated by mammography, which may have included contrast‐enhanced mammography, conventional B‐mode ultrasound, and SWE. Following this, elastography mean (E_mean), maximum (E_max), and ratio (E_ratio) variables were calculated for elasticity in kilopascals (kPa) and speed in metres per second (m/s).Results: Malignant (n = 113) samples were significantly higher than benign (n = 267) across all SWE variables [median (interquartile range)]; E_mean (kPa) [132.8 (34), vs. 41.9 (53.6), p < .001], E_mean (m/s) [6.9 (1), vs. 3.7 (2.2), p < .001]. The highest combined sensitivity and specificity were for E_max (97%, 73%) at >80 kPa, and E_mean (96%, 76%) at >5.2 m/s. Histopathological grade 3 (kPa), E_mean [145.8 (22.5), p = .012], E_max [147.8 (19.4), p = .009], and E_ratio [11.7 (6.6), p = .006] were significantly higher than grades 1 [129.2 (37.3), 133.2 (35.9), 7.53 (4.7)] and 2 [127.3 (36.4), 133.3 (34.2), 8.3 (6.1)].Conclusion: Breast elastography is a sensitive complementary technique that can distinguish between malignant and benign lesions and help characterise histological profile and grade.