Liquid biopsies using, free-circulating nucleic acids, exosomes and circulating tumor cells hold the promise to rework the diagnosis, management, and treatment of cancer as well as other diseases. Additionally, analysis of free circulating nucleic acids allows for early identification of genetic alterations in the unborn during pregnancy with minimal risks for the mother and therefore the unborn child.

Each year, quite 450,000 patients in the US and Europe are diagnosed with lung cancer. It is treated initially with surgical resection, followed by a mixture and chemotherapy. Over the past eight years, most of the new targeted therapies are developed for the treatment of both primary and recurrent/resistant carcinoma, which may prolong life substantially. The simplest practices require the molecular monitoring of the disease, to work out which mutation is driving the propagation of cells, and which therapy best targets that pathway.

However, monitoring the disease progression and relapse is problematic, as until recently this required additional surgical biopsies. For the patient, these procedures are often quite painful and stressful, which is why many biopsies are performed under local or maybe general anesthesia. Even minimal surgeries invariably result in some injury to living tissue and risk of infection.1 Tissue biopsies also might not capture enough relevant information, thanks to heterogeneity of the tumor, which may cause some disease genotypes to be present in one area of the tumor, but not the opposite.

Liquid Biopsies: Earlier, Faster, More Cost-Effective and Conservative

Now, a minimally invasive technique referred to as the liquid biopsy is starting to render some tissue biopsies and similar procedures unnecessary. QIAGEN is the world’s leader in helping researchers apply liquid biopsy technologies to get molecular biomarkers from blood, urine and other body fluids to watch cancer and other diseases. Clinical research during this field focuses on free-circulating nucleic acids, exosomes and circulating tumor cells.

Scientists have known about circulating nucleic acids since the 19th Century. Free-circulating nucleic acids are released from dying cells, elements of which are released into the blood and other body fluids. This phenomenon occurs in everyone, but some physiological states and symptom constellations, for instance, pregnant women or patients with cancers or autoimmune disorders, end in a significantly higher concentration of free-circulating nucleic acids. Exosomes are microvesicles (very small enclosures) shed by cells as a part of a biological communication system. Each exosome can carry a small cargo of genetic instructions in the form of RNA molecules through the blood, urine or other fluids. Taking these genetic messages from cell to cell within the body, exosomes are being called the “Twitter of the cells.”

The range of potential uses for liquid biopsies is even greater. Because taking blood or other body fluids is minimally invasive, liquid biopsies are often repeated as often as required – without major stress for the patient. Liquid biopsies could thus facilitate regular monitoring of cancer patients, evaluating the course of their treatment, also as permitting follow-up supported early detection of possible relapses. Research projects and new drug development also are likely to benefit from liquid biopsies’ potential for real-time insights into changes in tumor biology and tissues – which may cause resistance surely potential drugs. Researchers also are expecting new insights from exosomes, for instance, in cardiovascular and central nervous system disorders.