Assessment of different size tumor stiffness characteristic with shear wave elastography in a triple-negative human breast cancer implantation model / 中华超声影像学杂志

ABSTRACT

Objective:To investigate the stiffness characteristic of triple-negative human breast cancer at different size in a implantation nude female mice model using shear wave elastography(SWE) and to compare the clinical pathologic features of tumors with elasticity variables.Methods:Human breast cancer MDA-MB-231 cells were injected into 30 nude female mice and 27 transplanted tumors were successfully found in nude female mice. Ultrasound and SWE were longitudinally performed on maximum diameter plane of 21 tumours in 21 nude mice. The elastic parameters of maximal elasticity(Emax), mean elasticity (Emean) and standard deviation of elasticity(Esd) were recorded. The mice were divided into 3 groups according to the tumor size. They were group A with tumor size less than or equal to 5 mm, group B with tumor size greater than 5 mm and less than or equal to 10 mm, group C with tumor size larger than 10 mm and smaller than or equal to 15 mm. Compared with pathology, the relationships between Ki67 of transplanted tumor and elastic parameters were analyzed.Results:As the transplanted tumors increased, the values of Emax, Esd, Ki67 all increased. The lesions maximal size, Emax, Esd, Ki67 were significant higher in group B ( P<0.001, P=0.006, P=0.002, P=0.026) and group C ( P<0.001, P<0.001, P<0.001, P=0.028) than group A. The other parameters were not significantly different among the groups(all P>0.05). The size of transplanted tumors was significantly and positively correlated with Emax ( rs=0.673, P=0.001), Esd ( rs=0.661, P=0.001), and Ki67 ( rs=0.509, P=0.018). Conclusions:SWE Emax and Esd can reflect the tumor tissue stiffness change and biological activity during the tumor growth.