WHAT ARE CIRCULATING TUMOR CELLS (CTCS)?
Circulating tumor cells (CTCs) are cells that have detached from a primary tumor and circulate in the bloodstream. CTCs may travel to other areas and create new tumors in different tissues or organs (metastatic). Elevated CTCs at any time in the course of clinical treatment of metastatic cancer are indicators of progression.
WHY IS IT IMPORTANT TO TEST FOR CTCS?
The capture and detection of CTCs may have important prognostic and therapeutic implications, primarily because detection of tumor cells assists in early detection of relapse and in monitoring the response to treatment. The presence of tumor cells circulating in the blood is associated with shortened survival from various solid tumor cancers.
I HAVE BEEN DIAGNOSED WITH CANCER AND WILL SOON BEGIN TREATMENT. HOW IS CTC TESTING USEFUL TO ME?
If you have just been diagnosed with cancer, the optimal time to test the CTCs is prior to treatment (providing a baseline CTC count) and part way through treatment to determine if the CTC count is declining (indicating response to treatment).
In other words, the CTC count is a predictive indicator, in that it predicts response to treatment. If the CTC count rises, it indicates the cancer is not responding to the chosen treatment.
This provides your doctor with information that can help guide treatment planning and change your treatment(s) sooner if needed. It is also helpful to test the CTCs at the end of treatment, to determine the presence or absence of CTCs. The CTC count after treatment serves as a prognostic indictor (i.e. cancer-specific survival and risk for recurrence).
CANCER BIOMARKER TESTING
WHAT IS CANCER BIOMARKER TESTING?
Certain biological markers expressed by your particular cancer provide valuable information that help tailor your treatment.
For instance, if you have breast cancer and the tumor cells have high expression of a receptor called HER2/neu, you’re your treatment will consist of a targeted therapy called Herceptin.
If you have colon cancer and the tumor cells have do not have a mutation in a in the KRAS gene, then you may be a candidate for targeted therapy (i.e. Cetuximab). Identification of certain “driver mutations” is crucial to offering the most advanced therapies available.
At the time of original tumor biopsy or surgery, biomarker analysis on the tissue sample is routinely performed. However, it is well known that cancer cells can transform – especially if the cancer was localized at the time of diagnosis, but then spreads to another part of the body.
Sometimes it’s not possible or not advisable to obtain another tissue sample, due to the specific location – or there is insufficient volume in the sample for testing.
In these situations, a blood test serves as an accurate, non-invasive “liquid” biopsy that assist physicians in understanding the specific features of the disease and making decisions on current and future therapy.
CANCER BIOMARKER TESTING – PERFORMING TESTS
HOW IS THE TEST PERFORMED?
After the specimen is taken and sent off, reports are usually provided within 7 days.
IS THE COST OF THE TEST COVERED BY MY MEDICAL PLAN?
The BC medical services plan does not cover the cost of these tests. If you have extended health insurance, check with your provider if the cost of the test may be partially or fully reimbursable.
References: A complete list of studies, publications and posters can be found at: http://biocept.com/technology/publications/
Integrative cancer therapies can help with the side effects of chemotherapy and are used globally to fight cancer.