What are liquid biopsies and how are they used in the treatment of cancer?

Usually, when you hear the word “cancer”, the conversation most likely involves the mention of a biopsy. Tumour or tissue biopsies form early investigations of malignancy. It’s the first thing a doctor would recommend when a patient displays related symptoms and/or has a suspicious-looking lump. A tissue biopsy involves extracting cells from the tumour for further tests. With the help of molecular diagnostics, careful examination of tissue biopsy samples determines the presence of malignancy, enabling doctors to provide better diagnosis, prognosis and treatment decisions.  

Depending on where the tumour is located, the biopsy will involve a surgical intervention or procedure, which may be invasive, risky, painful, expensive and time-consuming. If the tumour is inaccessible, the diagnosis will be delayed or inaccurate. If the patient has other health conditions, further complications may prevent repeated biopsies if necessary.  

But today, though tumour biopsies remain the gold standard of cancer diagnosis and anti-cancer therapy, a new approach is being explored by researchers called “Liquid biopsy”.  

In this article, Helvetica Health Care (HHC) helps you discover what a liquid biopsy is and how this new approach can potentially complement or even replace conventional forms of cancer testing.  

Before we explore this concept in detail, here is a quick note on what we do. As a global health products and services provider, HHC provides a range of clinical/biological samples with needed characterisation, unique materials including POSITIVE HUMAN BLOOD, PLASMA and SERUM, and animal material, as well as BIOPSY SAMPLES.  

Although we operate from Geneva, Switzerland, our contacts enable us to source material in more than 50 countries worldwide and provide access to a network of clinical laboratories, transfusion and reference centres and pathology labs. In addition to this, we also offer a prospective collection of samples based on the parameters required and specifications and have access to large volumes of high-grade Human Serum (pooled or individual), as well as negative plasma in EDTA or Citrate. 

What are liquid biopsies?  

As the name suggests, liquid biopsies are tests that can trace cancer cells and cancer DNA found in bodily fluids. This avant-garde technology in cancer diagnosis allows doctors to acquire tons of vital information about a malignant tumour using simply blood, urine, plasma, cerebrospinal fluid or even saliva samples. These tests are, therefore, less invasive, simple, tolerable, convenient and repeatable.   

A liquid biopsy requires only 5 millilitres of blood, which makes the procedure quicker and easier to tolerate than a surgical biopsy. The collected fluid or blood sample is ‘spun down’ to retrieve 2 millilitres of blood plasma, which is then used to analyse tumour DNA. Early studies on liquid biopsies focused primarily on lung, breast, and prostate cancers, but this technology is anticipated to influence all types of cancer soon. 

What makes liquid biopsies important in cancer treatments?  

Before we move on to the importance of liquid biopsies, it is essential to highlight the role of blood plasma samples in cancer blood tests. A brief explanation of what blood plasma is will help you comprehend its significance in clinical research.

What is blood plasma? 

Blood plasma is the yellowish, liquid component of blood that remains after the blood cells (red blood cells, white blood cells, and platelets) have been removed. It constitutes approximately 55% of total blood volume and is composed of water, electrolytes, hormones, waste products, and proteins. One of the key proteins found in plasma is antibodies, which play a crucial role in immune responses.

How does blood plasma help cancer patients? 

Blood plasma is vital for cancer patients in multiple ways. Firstly, it is used to diagnose cancer through various blood tests, including the measurement of tumor markers. Secondly, plasma proteins, such as albumin and immunoglobulins, play a vital role in maintaining a patient’s overall health and immune system function during cancer treatment. Lastly, plasma-derived products can be used to manage some cancer-related complications, like anemia or low platelet counts.

To learn more about the functions of blood plasma and serum, please read our previous article. 

Let’s get on with liquid biopsies and their importance in cancer treatments. 

Tracing tumour DNA in the blood helps in better cancer detection 

Liquid biopsies use biofluids which are circulating and easily accessible sources of biomarkers. These biomarkers are cell-free and circulating tumour DNA (ctDNA). According to experts, scientists, and oncologists, these tests integrate tumour genetics with ctDNA analysis in a way that is not achievable with solid samples.  

Expert tumour biologists believe that examining a tiny tumour sample does not always give a complete picture of the extent of malignancy. This shortcoming prevents medical professionals from understanding the disease state, genetic mutations and metastases. Liquid biopsies involve DNA extraction from all cells, including those with genetic mutations and metastases that the doctor may be unaware of, thus giving a much more comprehensive view of the disease.  

Different types of liquid biopsies to test different tumours  

Liquid biopsies are versatile in the sense that different tests can analyse different types of tumour material, such as DNA, proteins, RNA, whole cells, etc. Different tumour molecules can be detected in various bodily fluids. As these fluids are readily accessible, collecting a sample is minimally invasive, and the test can be repeated more quickly than a tissue biopsy. 

Tumour DNA tracing enables early cancer detection and more targeted treatment decisions. 

One of the main benefits of liquid biopsy is its ability to detect malignancies early. Studies show that, in some cases, tumour DNA traces from the blood samples of patients help detect cancer well before a diagnosis is confirmed using conventional methods such as imaging tests. 

By studying traces of cancer’s DNA in the biofluids, oncologists can plan more targeted treatments for patients as they have a better understanding of disease progression or treatment resistance in terms of whether the patient is responding to the drug well globally or if the treatment is helping to shrink the tumours or even eliminate them.  

To know how HHC helps labs across continents in developing better solutions for public health improvement, call us now!