Laboratory Test Information Guide

Details for Circulating Tumor Cells

Test Name: Circulating Tumor Cells
Alternate Name(s): CTC
Laboratory: Flow Cytometry
Specimen Type: Venous Whole Blood
Collection Information: This test is only valid for venous whole blood drawn into a CellSave Tube (10ml draw).
Requisition: For further information and/or to enquire about ordering CTC tests, please contact:

Dr. Alison Allan
Tel: (519) 685-8600 x55134
Test Schedule: Monday-Friday
Turnaround time from when specimen
is received in testing laboratory:
10 days
Excluding weekends and Stat Holidays
Reference Range: See Interpretive Comments
Effective Date: 2014-09-08
Revised Date: 2020-06-01
Critical Value:  
Interpretive Comments: Our ISO-15189 accredited laboratory offers circulating tumor cell (CTC) analysis using the FDA- and Health Canada-approved CellSearch System (Menarini Silicon Biosystems, Inc).

The CellSearch is intended for clinical use in the enumeration of circulating tumor cells (CTCs) of epithelial origin in peripheral human blood samples. The assay predicts progression-free survival (PFS) and overall survival (OS) in patients with metastatic breast, colon and prostate cancer.
A CTC count of 5 cells/7.5mL blood or greater as determined by the assay is predictive of shorter PFS and OS for patients with metastatic breast and/or prostate cancer.
A CTC count of 3 cells/7.5mL blood or greater is predictive of shorter PFS and OS for patients with metastatic colon cancer.

In addition to enumeration in these indicated disease settings, other CTC analysis services are available including limited extra phenotyping of CTCs (1 additional marker of interest; i.e. HER-2/neu, EGFR, IGF-1R), investigation of CTCs in other epithelial tumor types, and custom studies.
Special Processing: N/A
Comments: After sample processing ferrofluid aggregation and/or non-ferrofluid aggregation may be seen in the sample tube. According to manufacturer’s recommendations sample is therefore unsatisfactory for processing.
Sample must be redrawn.
Method of Analysis: Analysis is performed using the CellSearch Circulating Tumor Cell Assay™ (Menarini Silicon Biosystems, Inc).
Critical Information Required: See Interpretive Comment
Storage & Shipment: Samples must be kept at 15-30ºC
Specimens are to be shipped/transported to the Flow Cytometry Laboratory at Victoria Hospital same day as collection.

Refrigeration can adversely affect sample integrity and therefore transport and storage of samples should be within 15-30C.

Specimens must be received and processed within 96 hours of collection by the Flow Cytometry Laboratory.
System Codes: 
Referred To:  

Questions? Comments? Contact Laura Gopaul