Circulating tumor cells (CTCs) in
blood of breast cancer patients:
Cytological detection and
technical characterization
Enrica Bresaola, Mara Jo Miller, Marco Picozzi, Maria
Teresa Sandri, Chiara Casadio
______________________
Cytology Unit, Department of Pathology & Laboratory Medicine
European Institute of Oncology, Milan, Italy
Introduction
 Circulating tumor cells (CTCs) were described for the
first time more than one century ago and their
occurrence in the bloodstream fit with the
hematogenous theory of metastatization
 Currently, their detection may play a pivotal role in
the prognosis and prediction of therapy efficacy,
providing us with insights into the clinical outcome,
cell dissemination, drug resistance and treatmentinduced cell death
Purpose
 To assess the feasibility of detecting CTCs in blood
samples of breast cancer patients using the Thin Prep®
cytological preparation after a concurrent analysis with
the CellSearch System (Veridex LLC, Warren, NJ)
 To further characterize these cells according to estrogen
receptor immunoreactivity and Her-2/neu gene status
evaluation by fluorescence in situ hybridization (FISH)
analysis
Materials and Methods
 7.5 ml of whole blood were drawn from breast cancer
patients into the CellSave Preservative Tube containing
a cellular preservative and processed within 72 hours
 The CellSearch Profile kit was then utilized to separate
the CTCs by treatment with iron particles coated with
antibodies against the Epithelial Cell Adhesion Molecule
(EpCAM) for capturing CTCs
 CTCs were then magnetically separated out and
concentrated into a remaining aliquot of 1ml
Materials and Methods
 This aliquot was centrifuged at 1700 rpm for 7 minutes
and the supernatant discarded
 The pellet was then added directly into the Preservcyt®
vial for subsequent processing of ThinPrep slides
 The slides were colored with H&E and evaluated
microscopically
 Estrogen receptor immunostaining and FISH analysis
were carried out according to previously refined
laboratory methods
Results
 A total of 106 blood samples, where the CellSearch
System obtained CTCs, were further evaluated
cytologically
 Of these, 60 were negative and 46 were positive for
malignant cells (range: 1-615) (Figure 1)
Figure 1
Results
 Immunocytochemistry for estrogen receptor was
performed in 7 samples and only one case showed ERpositive tumor cells
+ve cell
-ve cell
 10 cases were analyzed by FISH: 7 cases had no
amplification while in 3 cases no more cells were
detected
Conclusions
Cytological detection of CTCs in blood
specimens from breast cancer patients can
be useful in providing samples for testing
predictive indicators of prognosis and clinical
response during therapy