title: Magnetic Resonance Imaging after Completion of Neoadjuvant Chemotherapy Can Accurately Discriminate between No Residual Carcinoma and Residual Ductal Carcinoma In Situ in Patients with Triple-Negative Breast Cancer.
abstract: BACKGROUND
  The accurate evaluation of favorable response to neoadjuvant chemotherapy (NCT) is critical to determine the extent of surgery. We investigated independent clinicopathological and radiological predictors to discriminate no residual carcinoma (ypT0) from residual ductal carcinoma in situ (ypTis) in breast cancer patients who received NCT.
  
  
  METHODS
  Parameters of 117 patients attaining pathological complete response (CR) in the breast after NCT between January 2010 and December 2013 were retrospectively evaluated by univariate and multivariate analyses. All patients underwent mammography, ultrasound, and magnetic resonance imaging (MRI) before and after NCT.
  
  
  RESULTS
  There were 67 (57.3%) patients with ypT0. These patients were associated with hormone receptor-negative status, human epidermal growth factor receptor-2 (HER2)-negative tumors, and a higher likelihood of breast-conservation surgery. Baseline mammographic and MRI presentation of the main lesion, absence of associated microcalcifications, shape, posterior features, and absence of calcifications on ultrasound were significantly associated with ypT0. CR in mammography, ultrasound, or MRI after NCT was also related to ypT0. By multivariate analysis, independent predictors of ypT0 were the triple-negative subtype [Odds ratio (OR), 4.23; 95% confidence interval (CI), 1.11-16.09] and CR in MRI after NCT (OR, 5.23; 95% CI, 1.53-17.85). Stratified analysis by breast cancer subtype demonstrated that MRI well predicted ypT0 in all subtypes except the HER2-positive subtype. In particular, of 40 triple-negative subtypes, 22 showed CR in MRI and 21 (95.5%) were ypT0 after NCT.
  
  
  CONCLUSIONS
  Among imaging modalities, breast MRI can potentially distinguish between ypT0 and ypTis after NCT, especially in patients with triple-negative breast cancer. This information can help clinicians evaluate tumor response to NCT and plan surgery for breast cancer patients of all subtypes except for those with HER2-enriched tumors after NCT.
authors: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Seho
authors: S
authors: Park
authors: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Jung Hyun
authors: JH
authors: Yoon
authors: Division of Medical Oncology, Department of Internal Medicine, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Joohyuk
authors: J
authors: Sohn
authors: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Hyung Seok
authors: HS
authors: Park
authors: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Hee Jung
authors: HJ
authors: Moon
authors: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Min Jung
authors: MJ
authors: Kim
authors: Department of Radiology, Research Institute of Radiological Science, Severance Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Eun-Kyung
authors: EK
authors: Kim
authors: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Seung Il
authors: SI
authors: Kim
authors: Department of Surgery, Yonsei University College of Medicine, Seoul, Republic of Korea.
authors: Byeong-Woo
authors: BW
authors: Park
mesh_terms: D000328:Adult; D000970:Antineoplastic Agents / Q000627:therapeutic use; D001940:Breast / Q000473:pathology; D002277:Carcinoma / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D002285:Carcinoma, Intraductal, Noninfiltrating / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D017024:Chemotherapy, Adjuvant; D003936:Diagnosis, Computer-Assisted; D005189:False Positive Reactions; D005260:Female; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008327:Mammography; D008875:Middle Aged; D015999:Multivariate Analysis; D020360:Neoadjuvant Therapy; D012372:ROC Curve; D012189:Retrospective Studies; D016896:Treatment Outcome; D064726:Triple Negative Breast Neoplasms / Q000175:diagnosis* / Q000188:drug therapy / Q000473:pathology; D016217:Ultrasonography, Mammary
chemical_list: D000970:Antineoplastic Agents