title: pCR rates in patients with bilateral breast cancer after neoadjuvant anthracycline-taxane based-chemotherapy - A retrospective pooled analysis of individual patients data of four German neoadjuvant trials.
abstract: OBJECTIVE
  Patients with bilateral breast cancer (BBC) are usually excluded from participating in clinical trials and little is known about the response and outcome of BBC to neoadjuvant chemotherapy compared to unilateral BC (UBC).
  
  
  METHODS
  We prospectively captured the information on patients with BBC in our database treated within four neoadjuvant chemotherapy trials and collected retrospectively the rate of pathological complete response (pCR) defined as ypT0 ypN0, ypT0/is ypN0, ypT0 ypNX, clinical and histologic parameters. Synchronous carcinoma in the contralateral breast was considered as the non-indicator lesion. Patients with UBC only treated within the same neoadjuvant trials performed the control group.
  
  
  RESULTS
  From the 6727 patients treated within 4 German neoadjuvant trials 119 (1.8%) patients have been identified with the diagnosis of BBC. The pCR rate (ypT0 ypN0) was 12.6% in the non-indicator lesion group versus 10.9% the indicator lesion group versus 20.9% for patients with unilateral disease (p = 0.003). There were more advanced tumor stages and positive axillary lymph nodes in the indicator lesion than in the nonindicator lesion or in UBC. In 52.5% the molecular subtype was identical between indicator and non-indicator lesion with more triple negative and HER2 positive BC in the group of UBC. The disease free survival rate (DFS) was 25.8% for patients with UBC versus 39.6% for patients with BBC.
  
  
  CONCLUSIONS
  The selection for the indicator lesion was based on tumor size, nodal status and inclusion criteria. Patients with BBC patients had a lower pCR rate and a lower DFS.
authors.affiliation: Breast Unit, Kliniken-Essen-Mitte, Henricistrasse 92, 45138 Essen, Germany. Electronic address: m.reinisch@kliniken-essen-mitte.de.
authors.forename: Mattea
authors.initials: M
authors.lastname: Reinisch
authors.affiliation: Department of Obstetrics and Gynaecology, Universitätsfrauenklinik Ulm, Prittwitzstrasse 43, 89075 Ulm, Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Huober
authors.affiliation: German Breast Group, GBG Forschungs GmbH, Martin-Behaim-Strasse 12, 63263 Neu-Isenburg, Germany.
authors.forename: Gunter
authors.initials: G
authors.lastname: von Minckwitz
authors.affiliation: Department of Obstetrics and Gynaecology, Breast Unit, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Jens-Uwe
authors.initials: JU
authors.lastname: Blohmer
authors.affiliation: Institute of Pathology, Charitéplatz 1, 10117 Berlin, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Denkert
authors.affiliation: Department of Obstetrics and Gynaecology, Rotkreuzklinikum München, Taxisstrasse 3, 80637 München, Germany.
authors.forename: Claus
authors.initials: C
authors.lastname: Hanusch
authors.affiliation: Department of Obstetrics and Gynaecology, Sana Klinikum Offenbach, Germany.
authors.forename: Christian
authors.initials: C
authors.lastname: Jackisch
authors.affiliation: Breast Unit, Kliniken-Essen-Mitte, Henricistrasse 92, 45138 Essen, Germany.
authors.forename: Sherko
authors.initials: S
authors.lastname: Kümmel
authors.affiliation: National Center for Tumor Diseases - NCT, Im Neuenheimer Feld 460, 69120 Heidelberg, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Schneeweiss
authors.affiliation: Center for Familial Breast and Ovarian Cancer, University of Cologne, Kerpener Str. 34, 50931 Köln, Germany.
authors.forename: Kerstin
authors.initials: K
authors.lastname: Rhiem
authors.affiliation: German Breast Group, GBG Forschungs GmbH, Martin-Behaim-Strasse 12, 63263 Neu-Isenburg, Germany.
authors.forename: Bianca
authors.initials: B
authors.lastname: Lederer
authors.affiliation: Department of Obstetrics and Gynaecology, Schwanebecker Chaussee 50, 13125 Berlin, Germany.
authors.forename: Michael
authors.initials: M
authors.lastname: Untch
authors.affiliation: German Breast Group, GBG Forschungs GmbH, Martin-Behaim-Strasse 12, 63263 Neu-Isenburg, Germany.
authors.forename: Valentina
authors.initials: V
authors.lastname: Nekljudova V
authors.affiliation: German Breast Group, GBG Forschungs GmbH, Martin-Behaim-Strasse 12, 63263 Neu-Isenburg, Germany; Centrum for Haematology and Oncology, Bethanien, Frankfurt/M, Germany. Electronic address: Sibylle.loibl@gbg.de.
authors.forename: Sibylle
authors.initials: S
authors.lastname: Loibl
mesh_terms: D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D018943:Anthracyclines / Q000627:therapeutic use*; D000971:Antineoplastic Combined Chemotherapy Protocols / Q000627:therapeutic use*; D001943:Breast Neoplasms / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D001952:Bridged-Ring Compounds / Q000627:therapeutic use*; D017024:Chemotherapy, Adjuvant / Q000379:methods; D002986:Clinical Trials as Topic; D018572:Disease-Free Survival; D005260:Female; D005858:Germany; D006801:Humans; D008207:Lymphatic Metastasis; D008875:Middle Aged; D020360:Neoadjuvant Therapy / Q000379:methods*; D009378:Neoplasms, Multiple Primary / Q000188:drug therapy* / Q000401:mortality / Q000473:pathology; D011446:Prospective Studies; D012189:Retrospective Studies; D043823:Taxoids / Q000627:therapeutic use*; D047368:Tumor Burden; D055815:Young Adult
chemical_list: D018943:Anthracyclines; D001952:Bridged-Ring Compounds; D043823:Taxoids; C080625:taxane
keywords: Bilateral synchronous carcinoma of the breast; Outcome; Response under neoadjuvant chemotherapy; Survival