PMID- 27895501
OWN - NLM
STAT- PubMed-not-MEDLINE
LR  - 20200930
IS  - 1178-6930 (Print)
IS  - 1178-6930 (Electronic)
IS  - 1178-6930 (Linking)
VI  - 9
DP  - 2016
TI  - A FISH-based method for assessment of HER-2 amplification status in breast cancer 
      circulating tumor cells following CellSearch isolation.
PG  - 7095-7103
AB  - INTRODUCTION: Amplification of the HER-2/neu (HER-2) proto-oncogene occurs in 
      10%-15% of primary breast cancer, leading to an activated HER-2 receptor, 
      augmenting growth of cancer cells. Tumor classification is determined in primary 
      tumor tissue and metastatic biopsies. However, malignant cells tend to alter 
      their phenotype during disease progression. Circulating tumor cell (CTC) analysis 
      may serve as an alternative to repeated biopsies. The Food and Drug 
      Administration-approved CellSearch system allows determination of the HER-2 
      protein, but not of the HER-2 gene. The aim of this study was to optimize a 
      fluorescence in situ hybridization (FISH)-based method to quantitatively 
      determine HER-2 amplification in breast cancer CTCs following CellSearch-based 
      isolation and verify the method in patient samples. METHODS: Using healthy donor 
      blood spiked with human epidermal growth factor receptor 2 (HER-2)-positive 
      breast cancer cell lines, SKBr-3 and BT-474, and a corresponding negative control 
      (the HER-2-negative MCF-7 cell line), an in vitro CTC model system was designed. 
      Following isolation in the CellSearch system, CTC samples were further enriched 
      and fixed on microscope slides. Immunocytochemical staining with cytokeratin and 
      4',6-diamidino-2'-phenylindole dihydrochloride identified CTCs under a 
      fluorescence microscope. A FISH-based procedure was optimized by applying the 
      HER2 IQFISH pharmDx assay for assessment of HER-2 amplification status in breast 
      cancer CTCs. RESULTS: A method for defining the presence of HER-2 amplification 
      in single breast cancer CTCs after CellSearch isolation was established using 
      cell lines as positive and negative controls. The method was validated in blood 
      from breast cancer patients showing that one out of six patients acquired CTC 
      HER-2 amplification during treatment against metastatic disease. CONCLUSION: 
      HER-2 amplification status of CTCs can be determined following CellSearch 
      isolation and further enrichment. FISH is superior to protein assessment of HER-2 
      status in predicting response to HER-2-targeted immunotherapy in breast cancer 
      patients. This assay has the potential of identifying patients with a shift in 
      HER-2 status who may benefit from treatment adjustments.
FAU - Frithiof, Henrik
AU  - Frithiof H
AD  - Division of Oncology and Pathology.
FAU - Aaltonen, Kristina
AU  - Aaltonen K
AD  - Division of Oncology and Pathology.
FAU - Ryden, Lisa
AU  - Ryden L
AD  - Division of Surgery, Department of Clinical Sciences Lund, Lund University, Lund; 
      Department of Surgery, Skane University Hospital, Malmo, Sweden.
LA  - eng
PT  - Journal Article
DEP - 20161116
PL  - New Zealand
TA  - Onco Targets Ther
JT  - OncoTargets and therapy
JID - 101514322
PMC - PMC5117892
OTO - NOTNLM
OT  - breast neoplasms
OT  - circulating
OT  - fluorescence
OT  - human epidermal growth factor receptor 2
OT  - immunomagnetic separation
OT  - in situ hybridization
OT  - neoplastic cells
COIS- The authors report no conflicts of interest in this work.
EDAT- 2016/11/30 06:00
MHDA- 2016/11/30 06:01
PMCR- 2016/11/16
CRDT- 2016/11/30 06:00
PHST- 2016/11/30 06:00 [entrez]
PHST- 2016/11/30 06:00 [pubmed]
PHST- 2016/11/30 06:01 [medline]
PHST- 2016/11/16 00:00 [pmc-release]
AID - ott-9-7095 [pii]
AID - 10.2147/OTT.S118502 [doi]
PST - epublish
SO  - Onco Targets Ther. 2016 Nov 16;9:7095-7103. doi: 10.2147/OTT.S118502. eCollection 
      2016.