title: Evaluation of tumor stiffness by elastography is predictive for pathologic complete response to neoadjuvant chemotherapy in patients with breast cancer.
abstract: BACKGROUND
  Breast elastography (EG), which can objectively evaluate tumor stiffness, has been useful for differentiation of benign and malignant breast lesions. However, the value of EG for prediction of response to systemic therapy is poorly understood.
  
  
  METHODS
  The baseline evaluations of EG in 55 patients who received neoadjuvant chemotherapy were reviewed. We investigated the correlation between tumor stiffness and response to neoadjuvant chemotherapy. Tumor stiffness was evaluated by the Tsukuba elasticity scoring system.
  
  
  RESULTS
  The mean EG scores were significant lower for the clinical and pathologic complete response (pCR) groups than for the others. When we categorized patients into two groups according to tumor stiffness, 26 patients were assigned to the low EG group (soft, scores from 1 to 3) and 29 patients were assigned to the high EG group (hard, score 4 and 5). The low EG group had significantly higher clinical complete response and pCR rates than the high EG group (clinical complete response, low EG group 38 % vs. high EG group 10 %, P = 0.024; pCR, low EG group 50 % vs. high EG group 14 %, P = 0.003, respectively). Furthermore, multivariate analysis indicated that estrogen receptor, human epidermal growth factor receptor 2, and low EG (odds ratio 13.04, 95 % confidence interval 1.19-458.28, P = 0.035) were independent predictive factors of pCR.
  
  
  CONCLUSIONS
  Tumor stiffness evaluated by EG bears predictive potential for response to neoadjuvant chemotherapy. Stiffness evaluated by EG may be recognized as a clinically significant tumor characteristic, comparable to other data obtained by functional imaging techniques.
authors.affiliation: Department of Breast and Endocrine Surgery, Graduate School of Medical Sciences, Kumamoto University, Kumamoto, Japan.
authors.forename: Mitsuhiro
authors.initials: M
authors.lastname: Hayashi
authors.forename: Yutaka
authors.initials: Y
authors.lastname: Yamamoto
authors.forename: Mutsuko
authors.initials: M
authors.lastname: Ibusuki
authors.forename: Saori
authors.initials: S
authors.lastname: Fujiwara
authors.forename: Satoko
authors.initials: S
authors.lastname: Yamamoto
authors.forename: Saori
authors.initials: S
authors.lastname: Tomita
authors.forename: Masahiro
authors.initials: M
authors.lastname: Nakano
authors.forename: Keiichi
authors.initials: K
authors.lastname: Murakami
authors.forename: Ken-Ichi
authors.initials: K
authors.lastname: Iyama
authors.forename: Hirotaka
authors.initials: H
authors.lastname: Iwase
mesh_terms: D000328:Adult; D000368:Aged; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D018270:Carcinoma, Ductal, Breast / Q000000981:diagnostic imaging* / Q000188:drug therapy* / Q000378:metabolism; D017024:Chemotherapy, Adjuvant; D016009:Chi-Square Distribution; D054459:Elasticity Imaging Techniques; D005260:Female; D006801:Humans; D019394:Ki-67 Antigen / Q000378:metabolism; D016015:Logistic Models; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D018719:Erb-b2 Receptor Tyrosine Kinases / Q000378:metabolism; D011960:Receptors, Estrogen / Q000378:metabolism; D011980:Receptors, Progesterone / Q000378:metabolism; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D019394:Ki-67 Antigen; D018719:Erb-b2 Receptor Tyrosine Kinases; D011960:Receptors, Estrogen; D011980:Receptors, Progesterone; C508053:ERBB2 protein, human