Chemosensitivity testing is an emerging field in cancer care that tests circulating tumour cells found in a blood sample against various chemotherapeutic agents to determine the most effective drug.
Chemosensitivity testing customizes cancer care, and helps to ensure that only effective treatments are administered. Circulating tumour cell counts can also be monitored to help prevent disease progression and recurrence.
Blood is drawn at a local lab and sent overnight to Germany to be analyzed. Results are available within a week.
Circulating tumour cells (CTCs) are first isolated from a blood sample, and then analyzed for under- or over-expression of genes and for other cellular characteristics.
This information helps determine which chemotherapeutic and/or non-conventional therapy will have the highest probability of effectiveness for the given type and stage of cancer.
CTCs enter the bloodstream from a primary tumour, and they are used in chemosensitivity testing because they are responsible for the spread of cancer to distant organs and tissues (metastases).
CTCs often have different cellular genomics and characteristics than the primary tumour cells that are more commonly used in conventional cancer care to determine treatment. Focusing treatment exclusively on the primary tumour cells leaves many CTCs viable, and able to contribute to recurrence at a later date.
CTCs displaying drug resistant genes can also be identified in this process. This may be especially important for those who have already undergone chemotherapy, as drug resistance is unfortunately more prevalent in this population.
All of this helps to ensure ineffective treatments are not administered.
Success of therapy can be regularly monitored with CTC testing. A decline in CTC count indicates the therapy is effective and correlates with improved outcomes. However, should the number of CTCs increase during therapy, this would indicate the therapy is not effective, and offers an opportunity to change to a more successful treatment regimen.
CTC testing can also be used to monitor for cancer recurrence by identifying CTCs from tumours in preliminary stages that are too small to be detected by diagnostic imaging. Such early detection allows for earlier treatment and thus improved outcomes.
For further information about CTC and chemosensitivity testing used at the clinic, please visit the Maintrac and Biofocus websites. Blood is drawn at a local lab and sent overnight to Germany. Results are available within a week.