Combination of shear wave elastography and Ki-67 index as a novel predictive modality for the pathological response to neoadjuvant chemotherapy in patients with invasive breast cancer.
This study evaluated shear wave elastography (SWE) and SWE combined with the Ki-67 index as novel predictive modalities for the pathological response of invasive breast cancer to neoadjuvant chemotherapy (NAC).



The prospective study recruited 66 eligible patients from July 2014 to November 2015. Tumour stiffness, which corresponds with tumour progression and invasiveness, was assessed by quantitative SWE 1 d before biopsy (time point t0, elasticity E0), 1 d before next NAC cycle (t1-t5, E1-E5), and 1 d before surgery (t6, E6). The relative changes in SWE parameters after the first and second NAC cycles were considered as the variables [ΔE (t1), ΔE (t2)]. The pathological response was classified according to the residual cancer burden (RCB) protocol. Correlations between RCB scores and variables were evaluated. The predictive diagnostic performances of SWE parameters, Ki-67 index, and the predictive RCB (predRCB) score determined by a linear regression model were compared.



Some immunohistochemical and molecular factors and SWE parameters were significantly different among the three RCB groups. The ΔEmean(t2) and Ki-67 had significantly better diagnostic performance than other parameters regarding predicting the pathological response (the RCB-I response and RCB-III resistance). However, the correlation between ΔEmean(t2) and Ki-67 index was significantly weaker as a diagnostic predictor (r = 0.29). We generated a new predictive modality, predRCB, which is a multivariable linear regression model that combines ΔEmean(t2) and the Ki-67 index. The predRCB modality showed better diagnostic performance than SWE parameters and Ki-67 index alone.



Our findings highlight the potential utility for adding the Ki-67 index to the SWE results, which may improve the predictive power of SWE and facilitate personalising the treatment regimens of patients with breast cancer. These results should be validated in the future by performing a multicentre prospective study with a larger cohort.
Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Yan
Y
Ma
Department of Neurology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Shuo
S
Zhang
Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Li
L
Zang
Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Jing
J
Li
Department of Breast Surgery, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Jianyi
J
Li
Department of Pathology, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China.
Ye
Y
Kang
Department of Ultrasound, Shengjing Hospital of China Medical University, Shenyang, Liaoning, 110004, China. Electronic address: Renwd01@163.com.
Weidong
W
Ren
D000328:Adult; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D018275:Carcinoma, Lobular / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D003520:Cyclophosphamide / Q000008:administration & dosage / Q000627:therapeutic use; D000077143:Docetaxel; D054459:Elasticity Imaging Techniques; D015251:Epirubicin / Q000008:administration & dosage / Q000627:therapeutic use; D005260:Female; D005472:Fluorouracil / Q000627:therapeutic use; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D008408:Mastectomy; D015412:Mastectomy, Segmental; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D009367:Neoplasm Staging; D018365:Neoplasm, Residual; D011446:Prospective Studies; D043823:Taxoids / Q000008:administration & dosage; D000068878:Trastuzumab / Q000008:administration & dosage; D016896:Treatment Outcome; D047368:Tumor Burden; D016217:Ultrasonography, Mammary
D019394:Ki-67 Antigen; D043823:Taxoids; D000077143:Docetaxel; D015251:Epirubicin; D003520:Cyclophosphamide; D000068878:Trastuzumab; D005472:Fluorouracil
Breast cancer; Ki-67 index; Neoadjuvant chemotherapy; Predict; Shear wave elastography