title: Diffusion-weighted imaging in assessing pathological response of tumor in breast cancer subtype to neoadjuvant chemotherapy.
abstract: OBJECTIVE
  To investigate the efficacy of diffusion-weighted imaging (DWI) for reflecting and predicting pathological tumor response in breast cancer subtype to neoadjuvant chemotherapy (NAC).
  
  
  METHODS
  The retrospective study included 176 patients with breast cancer who underwent magnetic resonance imaging (MRI) examinations before and after NAC prior to surgery. The pre- and post-NAC apparent diffusion coefficient (ADC) values of tumor were measured respectively on DWI. The pathological response was classified into either a complete response (pCR) or as a noncomplete response (pNCR) to NAC with the Miller & Payne system. The relationship between the ADC value and the pathological response was assessed according to intrinsic subtypes (Luminal A, Luminal B, HER2-enriched, and triple negative) defined by immunohistochemical features.
  
  
  RESULTS
  Multiple comparisons respectively showed that pre-NAC and post-NAC ADC were significantly different among four subtypes (P < 0.001). After the comparison between two different subtypes, the pre-NAC ADC value of the triple-negative and HER2-enriched subtypes were significantly higher than Luminal A (P < 0.001 and P < 0.001) and Luminal B subtype (P < 0.001 and P = 0.009), and the post-NAC ADC of triple-negative subtype was significantly higher than the others (P < 0.001). The pre-NAC ADC of pCRs was significantly lower than that of pNCRs only in the triple-negative subtype among four subtypes (P < 0.001), and the post-NAC ADC of pCRs was significantly higher than that of pNCRs in each subtype (P < 0.001).
  
  
  CONCLUSIONS
  DWI appears to be a promising tool to determine the association of pathological response to NAC in breast cancer subtypes.
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Jinan, P.R. China.
authors.forename: Shangang
authors.initials: S
authors.lastname: Liu
authors.affiliation: Department of Radiation Oncology, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Jinan, P.R. China.
authors.forename: Ruimei
authors.initials: R
authors.lastname: Ren
authors.affiliation: Department of Radiology, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Jinan, P.R. China.
authors.forename: Zhaoqiu
authors.initials: Z
authors.lastname: Chen
authors.affiliation: Department of Breast surgery, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Sciencee, Jinan, P.R. China.
authors.forename: Yongsheng
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Department of Radiology, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Jinan, P.R. China.
authors.forename: Tingyong
authors.initials: T
authors.lastname: Fan
authors.affiliation: Department of Interventional MRI, Shandong Medical Imaging Research Institute, Shandong University, Jinan, P.R. China.
authors.forename: Chengli
authors.initials: C
authors.lastname: Li
authors.affiliation: Department of Medicine Oncology, Shandong Cancer Hospital and Institute, School of Medicine and Life Sciences, University of Jinan-Shandong Academy of Medical Science, Jinan, P.R. China.
authors.forename: Pinliang
authors.initials: P
authors.lastname: Zhang
mesh_terms: D000328:Adult; D000368:Aged; D018906:Antineoplastic Agents, Alkylating / Q000008:administration & dosage; D001940:Breast / Q000473:pathology; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology*; D017024:Chemotherapy, Adjuvant; D003520:Cyclophosphamide / Q000008:administration & dosage; D038524:Diffusion Magnetic Resonance Imaging; D004317:Doxorubicin / Q000008:administration & dosage; D005260:Female; D006801:Humans; D007150:Immunohistochemistry; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016896:Treatment Outcome
chemical_list: D018906:Antineoplastic Agents, Alkylating; D004317:Doxorubicin; D003520:Cyclophosphamide
keywords: breast cancer subtype; diffusion-weighted imaging; magnetic resonance imaging; neoadjuvant chemotherapy; pathological response