New Delhi: The recently published study in the British Medical Journal (Oncology) found that there has been a shocking 79 per cent increase in new cancer cases among individuals under the age of 50 over the past three decades on a global scale.
The study encompassing 29 types of cancers across 204 countries and regions, including India found the number of cancer patients under 50 surged from 1.82 million in 1990 to a staggering 3.26 million in 2019. Also, the corresponding deaths due to these cancers increased by 28 per cent during the same period.
The dramatic rising trend witnessed in cancer cases calls for advanced tests and resources to meet the growing demand for timely detection and treatment. Non-invasive or minimally invasive approaches are more desirable in the era of personalised medicine to know the molecular composition and characterization of a patient’s tumour.
One such approach is Liquid Biopsy which has the potential to help clinicians screen for disease, stratify patients, and follow patients undergoing surveillance and also offer an opportunity to detect early lesions in cases where tissue biopsy is difficult, as per NIH National Cancer Institute.
Genomic Liquid Biopsy is an approach that uses body fluids such as blood, urine, saliva, stool, and sputum from patients suspected to have early-stage cancer as well as those at high risk of developing cancer. This refers to detecting circulating tumor cells (CTC), circulating tumor DNA (ctDNA), circulating exosomes and other analytes in body fluids, such as serum, plasma, and urine which help in molecularly characterising the tumour and monitor genetic changes over time.
The utilization of liquid biopsy has witnessed a notable upsurge in recent years shared Dr Manish Singhal, Senior Consultant, Oncology, Indraprastha Apollo Hospital. He states that the escalation can predominantly be attributed to advancements in technology and the enhanced outcomes yielded that have garnered greater reliability, their indications have shown improvement, collectively enhancing the momentum that liquid biopsy has attained.
Liquid Biopsy over Tissue Biopsy
Currently, tissue biopsy is the “gold standard” for diagnosis of cancer. The medical procedure involves taking a small sample of the tissue where the cancer may be present so that it can be studied under a microscope for further analysis. Tissue biopsy offers reliable results however, some limitations like time taken, feasibility and cost still exist.
“Liquid biopsy obviates the need for patients to undergo tissue biopsies, a procedure not always easily repeatable. The dynamic nature of cancer is well-understood—cancer genomes evolve continuously, with mutations developing over time. The second notable utility stems from its ability to provide a comprehensive perspective of DNA. Given that the body sheds DNA from different locations, liquid biopsy captures DNA emanating from all segments of the tumor. In contrast, traditional biopsies are restricted to samples from a single site, prohibiting the gathering of data from multiple locations. Consequently, liquid biopsy stands capable of furnishing a more holistic understanding of DNA mutations. Moreover, it enables assessment of the overall tumor load and tumor mutation burden—essential indicators for treatment evaluation and prognosis,” explained Dr Manish Singhal.
To get a broader perspective on the scope of Liquid Biopsy, ETHealthworld spoke to genomics-driven research and diagnostics company-MedGenome which was the first to launch the liquid biopsy test in India in 2018.
Elaborating on choosing this cancer detection approach, Dr Vedam Ramprasad, CEO at MedGenome said, “When a 70-year-old individual undergoes a lung biopsy, there is a 10 per cent chance that the lung might collapse due to the procedure. This concern prompted us to explore liquid biopsy, which has been gaining prominence in recent years. In practice, we’re witnessing the effectiveness of liquid biopsies in various scenarios. About 50 per cent of the liquid biopsies we conduct are for cases where traditional biopsies are not feasible. This illustrates the transformative potential of this approach.”
A tissue biopsy may not be possible in almost 20 to 30 per cent of patients. Highlighting cases where a liquid biopsy can be beneficial Dr Suruchi Aggarwal, Head – Scientific Affairs, MedGenome said, “Tissue biopsy is very focused which may miss out important alterations present in other metastatic sites, but liquid biopsy is capable of detecting those as well. Liquid biopsy is also quite helpful where tumor biopsy is not possible due to reasons like the biopsy site being inaccessible or the patient being unwilling to undergo biopsy as it will mimic the DNA shed from the tumor. Hence, liquid biopsy is a test which is a promising alternative to tissue biopsy test and can be used as an adjunct also.”
In essence, the major advantages of liquid biopsy are its minimally invasive nature, avoiding the need for repetitive intrusive procedures, and its capacity to offer a panoramic view of DNA mutations by utilizing shed DNA from various bodily locations. These attributes highlight the significance and efficiency of liquid biopsy as a diagnostic tool in the realm of cancer management.
Future of Liquid Biopsy in Cancer Detection
The objective behind conducting a liquid biopsy lies in the analysis of the tumor genome, with the aim of identifying potential mutations that could respond to existing therapeutic agents. In the realm of medical practice, the liquid biopsy technique is typically employed when all available avenues of treatment have been explored, stated Dr Manish Singhal.
Sharing the positive outlook on liquid biopsy for cancer detection, Dr Ramprasad said, “The technology has already undergone successful clinical trials in the US and Europe, showing promising results in terms of sensitivity and specificity. By analyzing blood samples for specific mutations, it could become a routine preventive healthcare practice akin to regular blood tests.”
However, to make it accessible and practical for countries like India, where cost considerations are critical, Dr Ramprasad concluded by saying that there is a need to localize the technology, adapt it to our unique disease landscape, and work toward reducing its cost.
Liquid Biopsy holds immense potential to revolutionize cancer screening by offering a non-invasive, cost-effective, and early detection method, a crucial aspect in reducing cancer-related mortality rates.