Circulating Tumor Cells (CTC) for Breast Cancer by CellSearch, Blood
NY State Approved Indicates the status of NY State approval and if the test is orderable for NY State clients.
As an aid in monitoring patients with metastatic breast cancer
Special Instructions and Forms Describes specimen collection and preparation information, test algorithms, and other information pertinent to test. Also includes pertinent information and consent forms to be used when requesting a particular test
Reporting Name A shorter/abbreviated version of the Published Name for a test; an abbreviated test name
Circulating Tumor Cells, Breast, B
CTC (Circulating Tumor Cells)
Metastatic Breast Cancer
CTC (Circulating Tumor Cells)
Metastatic Breast Cancer
Specimen Type Describes the specimen type needed for testing
Specimen Required Defines the optimal specimen. This field describes the type of specimen required to perform the test and the preferred volume to complete testing. The volume allows automated processing, fastest throughput and, when indicated, repeat or reflex testing.
Specimen must be shipped immediately to ensure processing can be completed within 96 hours of draw. Send specimen Monday through Friday only and not the day before a holiday.
Container/Tube: Circulating Tumor Cell Collection Kit (Supply T630) containing CellSave tubes
Specimen Volume: 15 mL in 2 CellSave tubes each containing 7.5 mL
Collection Instructions: Send specimen on same day of draw.
Additional Information: Date and time of draw are required.
Forms: If not ordering electronically, submit a Pathology/Cytology Request Form (Supply T246) with the specimen.
Specimen Minimum Volume Defines the amount of specimen required to perform an assay once, including instrument and container dead space. Submitting the minimum specimen volume makes it impossible to repeat the test or perform confirmatory or perform reflex testing. In some situations, a minimum specimen volume may result in a QNS (quantity not sufficient) result, requiring a second specimen to be collected.
Mild reject; Gross reject
Specimen drawn in a tube other than CellSave tube or specimen submitted for reasons other than monitoring metastatic breast carcinoma
Specimen Stability Information Provides a description of the temperatures required to transport a specimen to the laboratory. Alternate acceptable temperature(s) are also included.
|Whole blood||Ambient||4 days|
Clinical Information Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test
In patients with metastatic cancer, tumor cells may be present in the bloodstream (circulating tumor cells: CTCs). Studies suggest that the number of CTCs is associated with progression-free and overall survival in patients with metastatic breast cancer.(1,2) Serial testing for CTCs, in conjunction with other clinical methods for monitoring breast cancer, can assist physicians in the management of these patients.(3)
Reference Values Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.
An interpretive report will be provided.
Results are reported as favorable or unfavorable. In patients with metastatic breast cancer, unfavorable results (> or =5 circulating tumor cells/7.5 mL of blood) are predictive of shorter progression-free survival and shorter overall survival.(1)
Cautions Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances
This test is FDA approved for use only in patients with metastatic breast cancer; it is not approved for patients with nonmetastatic breast cancer. Physicians are encouraged to limit their use of this test to monitoring patients with metastatic breast cancer until such time that the results from multisite studies reported in the peer-reviewed literature support its use in other malignances.
This test does not predict whether patients with unfavorable results will have better clinical outcomes if they are switched to alternative treatment regimens. It does not provide information about the primary site of a tumor.
Patients on doxorubicin (Adriamycin) must wait a minimum of 7 days after administration before blood is drawn for this test.
Blood specimens must be drawn in a CellSave tube and received in the laboratory for processing within 96 hours of the blood draw.
The presence of ferrofluid aggregates observed after processing a patient specimen may lead to false negative results. A result from a specimen in which aggregation is observed and the circulating tumor cells count is below 5 is invalid and the test is canceled per manufacturer's instructions. A retest is advised.
Clinical Reference Provides recommendations for further in-depth reading of a clinical nature
1. Cristofanilli M, Budd GT, Ellis MJ, et al: Circulating tumor cells, disease progression, and survival in metastatic breast cancer. N Engl J Med 2004;351:781-791
2. Allard WJ, Matera J, Miller MC, et al: Tumor cells circulate in the peripheral blood of all major carcinomas but not in healthy subjects or patients with nonmalignant diseases. Clin Cancer Res 2004 Oct 15;10:6897-6904
3. Cristofanilli M, Hayes DF, Budd GT, et al: Circulating tumor cells: a novel prognostic factor for newly diagnosed metastatic breast cancer. J Clin Oncol 2006 Mar 1;23:1420-1430
Method Description Describes how the test is performed and provides a method-specific reference
The CellSearch system consists of a CellTracks AutoPrep System and a CellTracks Analyzer. The AutoPrep system uses a ferrofluid reagent conjugated with monoclonal antibodies to epithelial cell adhesion molecule (EpCAM) to immunomagnetically separate epithelial cells from other blood components. Because the epithelial cell enrichment with EpCAM does not result in a completely pure epithelial cell population, the CellSearch System also utilizes 3 stains (DAPI, phycoerythrin [PE]-labeled cytokeratins [CK], and allophycocyanin [APC]-labeled CD45) to help distinguish true circulating tumor cells (CTCs) from contaminating leukocytes. DAPI stains the nuclei of cells and helps distinguish true cells from nonspecific debris. CTCs are identified with PE-labeled antibodies to CK 8, CK18, and CK19. Leukocytes are identified with APC-labeled antibodies to CD45. Cells that are DAPI+/CD45-/CK+ are classified as tumor cells, while all other staining combinations represent noncirculating tumor cells (eg, leukocytes or noncellular debris).(Riethdorf S, Fritche H, Muller V, et al: Detection of circulating tumor cells in peripheral blood of patients with metastatic breast cancer: a validation study of the CellSearch machine. Clin Cancer Res 2007 Feb 1;13:920-928)
Day(s) and Time(s) Test Performed Outlines the days and times the test is performed. This field reflects the day and time the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time required before the test is performed. Some tests are listed as continuously performed, which means assays are performed several times during the day.
Monday through Friday, Sunday
Analytic Time Defines the amount of time it takes the laboratory to setup and perform the test. This is defined in number of days. The shortest interval of time expressed is "same day/1 day," which means the results may be available the same day that the sample is received in the testing laboratory. One day means results are available 1 day after the sample is received in the laboratory.
Maximum Laboratory Time Defines the maximum time from specimen receipt at Mayo Medical Laboratories until the release of the test result
Performing Laboratory Location The location of the laboratory that performs the test
Test Classification Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer's instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR), Investigation Use Only (IUO) product, or a Research Use Only (RUO) product.
This test has been cleared or approved by the U.S. Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.
CPT Code Information Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Medical Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.
86152-Cell enumeration using immunologic selection and identification in fluid specimen (eg, circulating tumor cells in blood)
86153-Cell enumeration using immunologic selection and identification in fluid specimen (eg, circulating tumor cells in blood); physician interpretation and report when required
LOINC® Code Information Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the result codes returned for this test or profile.
|Result ID||Reporting Name||LOINC Code|
|50640||Reason for Referral||42349-1|
|50643||Reviewed By||In Process|