title: Diagnosis of pathological complete response to neoadjuvant chemotherapy in breast cancer by minimal invasive biopsy techniques.
abstract: BACKGROUND
  Neoadjuvant chemotherapy (NACT) is widely used as an efficient breast cancer treatment. Ideally, a pathological complete response (pCR) can be achieved. Up to date, there is no reliable way of predicting a pCR. For the first time, we explore the ability of minimal invasive biopsy (MIB) techniques to diagnose pCR in patients with clinical complete response (cCR) to NACT in this study. This question is of high clinical relevance because a reliable pCR prediction could have direct implications for clinical practice.
  
  
  METHODS
  In all, 164 patients were included in this review-board approved, multicenter pooled analysis of prospectively assembled data. Core-cut (CC)-MIB or vacuum-assisted (VAB)-MIB were performed after NACT and before surgery. Negative predictive values (NPV) and false-negative rates (FNR) to predict a pCR in surgical specimen (diagnose pCR through MIB) were the main outcome measures.
  
  
  RESULTS
  Pathological complete response in surgical specimen was diagnosed in 93 (56.7%) cases of the whole cohort. The NPV of the MIB diagnosis of pCR was 71.3% (95% CI: (63.3%; 79.3%)). The FNR was 49.3% (95% CI: (40.4%; 58.2%)). Existence of a clip marker tended to improve the NPV (odds ratio 1.98; 95% CI: (0.81; 4.85)). None of the mammographically guided VABs (n=16) was false-negative (FNR 0%, NPV 100%).
  
  
  CONCLUSIONS
  Overall accuracy of MIB diagnosis of pCR was insufficient to suggest changing clinical practice. However, subgroup analyses (mammographically guided VABs) suggest a potential capacity of MIB techniques to precisely diagnose pCR after NACT. Representativity of MIB could be a crucial factor to be focused on in further analyses.
authors.affiliation: Department of Gynecology, University Breast Unit, Im Neuenheimer Feld 440, 69120 Heidelberg, Germany.
authors.forename: Joerg
authors.initials: J
authors.lastname: Heil
authors.affiliation: Kliniken Essen Mitte, Klinik für Senologie, Henricistraße 92, 45136 Essen, Germany.
authors.forename: Sherko
authors.initials: S
authors.lastname: Kümmel
authors.affiliation: Department of Gynecology, University Breast Unit, Im Neuenheimer Feld 440, 69120 Heidelberg, Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Schaefgen
authors.affiliation: Department of Gynecology and Obstetrics, Technische Universität München, Ismaninger Straße 22, 81675 München, Germany.
authors.forename: Stefan
authors.initials: S
authors.lastname: Paepke
authors.affiliation: Department of Gynecology, Martin-Luther-Universität Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle an der Saale, Germany.
authors.forename: Christoph
authors.initials: C
authors.lastname: Thomssen
authors.affiliation: Institute of Medical Biometry and Informatics, University of Heidelberg, Im Neuenheimer Feld 305, 69120 Heidelberg, Germany.
authors.forename: Geraldine
authors.initials: G
authors.lastname: Rauch
authors.affiliation: Kliniken Essen Mitte, Klinik für Senologie, Henricistraße 92, 45136 Essen, Germany.
authors.forename: Beyhan
authors.initials: B
authors.lastname: Ataseven
authors.affiliation: Department of Gynecology, Martin-Luther-Universität Halle-Wittenberg, Ernst-Grube-Straße 40, 06120 Halle an der Saale, Germany.
authors.forename: Regina
authors.initials: R
authors.lastname: Große
authors.affiliation: Kliniken Essen Mitte, Klinik für Senologie, Henricistraße 92, 45136 Essen, Germany.
authors.forename: Volker
authors.initials: V
authors.lastname: Dreesmann
authors.affiliation: Department of Gynaecology and Obstetrics, Interdisciplinary Breast Centre, Klinikum Esslingen, Hirschlandstraße 97, 73730 Esslingen, Germany.
authors.forename: Thorsten
authors.initials: T
authors.lastname: Kühn
authors.affiliation: German Breast Group c/o GBG Forschungs GmbH, Schleussnerstrasse 42, 63263 Neu-Isenburg, Germany.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Loibl
authors.affiliation: Department of Gynecology, Charité, Chariteplatz 1, 10117 Berlin, Germany.
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Blohmer
authors.affiliation: German Breast Group c/o GBG Forschungs GmbH, Schleussnerstrasse 42, 63263 Neu-Isenburg, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: von Minckwitz
mesh_terms: D000328:Adult; D000368:Aged; D001940:Breast / Q000473:pathology*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000473:pathology* / Q000601:surgery; D017024:Chemotherapy, Adjuvant; D005188:False Negative Reactions; D005260:Female; D006801:Humans; D061705:Image-Guided Biopsy / Q000379:methods*; D008875:Middle Aged; D020360:Neoadjuvant Therapy; D011237:Predictive Value of Tests; D012189:Retrospective Studies; D016896:Treatment Outcome