Blood Test Could Provide Insight Into Patients' Metastatic Cancer

A new blood test that analyses DNA shed by metastatic cancers could reveal characteristics unique to each patient's tumour and help develop a more personalised treatment plans.

The blood test focuses on circulating tumour DNA (ctDNA). By sequencing the complete genome of ctDNA, researchers can learn about the different metastases spread throughout the body.

"A key goal in cancer research is to better understand metastatic cancer in each affected person so we can select the best treatments and avoid giving toxic therapies to people who will not derive benefit," senior author Alexander Wyatt, MD, DPhil, assistant professor of genitourinary cancer genomics at the University of British Columbia, Vancouver, Canada, and senior research scientist at the Vancouver Prostate Centre. Biopsies of metastatic cancer are rarely performed since they are invasive and have risks of complications. n the past, this major barrier has prevented the widespread study of metastatic cancer and progress to better treatment of this lethal disease.

Test Methods
Blood-based biopsy technology, also known as "liquid biopsy," has emerged as a tool for clinical cancer genotyping and longitudinal disease monitoring. Tests that use ctDNA have begun to influence the clinical management of people with cancer, the study authors write, though the full potential for understanding metastatic cancer biology hasn't yet been unlocked.

Escapee cancer cells in the blood, or 'CTCs' as they are known, can be found by a simple blood test.

A CTC Count test finds existing escapee cancer cells (CTCs) in a blood sample and counts them. Monitoring changes in cancer activity over time is made easy with this test. 

A CTC Count every 3-6 months is the best way to:

1. Monitor the effectiveness of cancer treatment
2. Assess changes in cancer aggressiveness
3. Determine risk of cancer spread, recurrence or relapse

More Medical Oncologists are becoming interested in supporting this type of test and creating personalised protocols.