Overview of Liquid Biopsy

What is a liquid biopsy?

A liquid biopsy is simply a test performed on a sample of biological fluid (such as blood, urine, saliva etc) taken from a patient.

Liquid biopsy has gained a lot of attention in the molecular diagnostics field as a non-invasive alternative to tissue biopsy. For example, with a simple blood draw, it is possible to analyze circulating tumor DNA or circulating tumor cells to answer molecular questions about  a patients’ tumor, thus sparing invasive and sometimes painful procedures to access the tumor directly.

Moreover, liquid biopsies can be repeated during the course of the disease and provide real-time information on how the tumor is changing in response to therapy and what could be the best approach to address it.

What is a Circulating Tumor Cell (CTC)?

One of the biomarkers that can be analyzed through liquid biopsy are circulating tumor cells, which are tumor cells released into the blood and can reveal a wide range of information. Isolation and analysis of circulating tumor cells is technically challenging because these cells are extremely rare but technologies have been developed to capture, count and isolate these rare cells to gain insight on the tumor.

How can liquid biopsy help to monitor my disease?

Increasing evidence suggests that liquid biopsy could enhance the clinical management of different types of tumors by improving early diagnosis, predicting prognosis, detecting recurrence, and monitoring response to treatment.

The presence of CTCs in the peripheral blood is associated with decreased progression-free survival and decreased overall survival in patients with metastatic breast, colorectal, or prostate* cancer.
Evaluation of the number of CTCs at any time during the course of disease can be used to monitor therapy response and to predict patient outcomes.

Ask your doctor about liquid biopsy testing, to find out if this test is right for you.

*Metastatic prostate cancer patients were defined as having two consecutive increases in the serum marker prostate-specific antigen above a reference level, despite standard hormonal management. These patients are commonly described as having androgen-independent, hormone-resistant, or castration-resistant prostate cancer.