Editorial
The Liquid Biopsy: Where a Blood Sample Can Reveal Many Secrets
Georges El Hachem*
Department of Medical Oncology, Institut Jules Bordet, Brussels, Belgium
*Corresponding author: Georges El Hachem, Department of Medical Oncology, Institut Jules Bordet, Brussels, Belgium
Published: 18 Feb, 2018
Cite this article as: El Hachem G. The Liquid Biopsy:
Where a Blood Sample Can Reveal
Many Secrets. Clin Oncol. 2018; 3:
1419.
Editorial
Medical Oncology is one the most rapidly evolving fields in the Medicine with drastic
improvement in the diagnostic and therapeutic procedures. However, the heterogeneity of the
disease with a difference between the primary lesion and the disseminated deposits, as well as the
response assessment and the early detection of recurrence remain big challenges. Despite the use
of effective loco-regional and systemic staging techniques, many cases of small micro-metastatic
lesions continue to be undetectable by current imaging procedures, knowing that their early
detection may prevent the development of incurable disease. Moreover, there has always been
some limitations to biopsy certain lesions that can be molecularly different from the primitive one.
Besides, many therapeutic decisions are often based on the characteristics of the primary tumor,
without taking into consideration the spatial and temporal tumor heterogeneities. Consequently,
the entity of circulating biomarkers, also called liquid biopsy, was developed. It mainly consists of
utilizing circulating tumor cells (CTCs) and circulating tumor DNA (ctDNA).
Tumors can liberate cells, called ‘’tumor cells’’, that enter the blood stream, and become
circulating cells with the possibility of analyzing them via different techniques. When the cells
become necrotic or after apoptosis, they release their DNA in the blood stream, known as ctDNA.
Therefore, they play the role of non-invasive, real-time liquid biopsies in cancer patients, becoming
an individual archive for the disease upon progression or regression.
Many trials are ongoing to demonstrate the utility of liquid biopsies in the management of
oncologic patients. These are non-invasive, promising, and accurate tools allowing the monitoring
of tumor evolution. Many studies showed their potential in detecting early recurrence even before
the development of metastatic disease. In the advanced disease, they contributed to the detection
of resistance mechanisms to certain cytotoxic treatments. A correlation with the response to
treatment and consequently the survival was also demonstrated. So, the liquid biopsies have
a prognostic role and may become an effective tool to assess and follow response to treatment,
avoiding the continuation of unnecessary regimens, thus resulting in a better orientation of the
treatment decisions. What is more interesting is that, in the early setting, the detection of the CTCs
and ctDNA after a conventional standard adjuvant therapy may identify a subgroup of patients
requiring additional treatments. Further studies are still needed to investigate their role as a
surrogate, predictive and sensitive biomarker and to overcome their limitations, mainly the lack of
technical standardization.