Next Generation Sequencing (NGS) – A Revolution in Cancer Diagnostics

Keerthi Ranganathan

Scientific Content Developer
4baseCare

In the era of personalised medicine, genomic testing has become an indispensable tool in clinical practice. Genomics is no longer restricted to research settings. Clinicians are more inclined to know the underlying genetic cause of diseases like cancer, for precise treatment planning and management of the disease. Next Generation Sequencing (NGS) is a revolutionised version of Sanger Sequencing (Chain Termination) which is a method of determining the order of the nucleotide sequence in a given genome. It has made stupendous contributions in many areas of research, clinical diagnostics, food industry, etc.

The first whole Human Genome Project (HGP) was done by the Sanger sequencing-based method, investing billions of dollars and dedicating almost over a decade of time. But with NGS, one can sequence the whole of the human genome, which is roughly about 3.2 giga bases in size, in a matter of two days. 

NGS has made a significant impact in the field of life science research before it made its entry in the molecular diagnostic sphere, especially in the field of Oncology and other genetic disorders. The reason for NGS to become such an indispensable tool is majorly its affordability, fast turnaround time for high sample volumes, ability to sequence hundreds to thousands of genes or gene regions simultaneously (information on DNA and RNA variant and Genomic Signatures) in lesser cost with less error, thus minimizing the side effects or over treatment.

The completion of the Human Genome Project In 2003 revealed that our DNA sequences are not the same and vary greatly among individuals. If our genetic sequence isn’t the same, how can the diseases that are caused due to genetic aberrations be the same, and more importantly, how can the treatment approach for them be the same.

Before the discovery of the whole human genome sequence, the clinicians approached the treatment of diseases with a ‘One size fits all’ concept where patients with the same disease would receive the same treatment. In such a case, some would benefit from the treatment, some would show adverse effects, and some would show no effect at all.

In one run, DNA sequencing by NGS includes whole-genome, whole-exome, and targeted sequencing, which focuses on a selection of genes of interest for a specific disease. An NGS can provide insights on the total genetic landscape of the disease with better resolution, providing enough information for the clinicians to manage the disease in a more personalised, effective, and precise way, while also leading to reduced clinical reporting time.

So, technology like NGS that can provide all the necessary information in less time with less tissue in a single go has revolutionised cancer treatment in the past few years. The most crucial aspect for a cancer patient is TIME, and when we are able to save such a significant amount of time with the NGS approach for cancer diagnostics and subsequent treatment guidance, what could be more rewarding for a cancer patient and also for the doctors.

NGS has revolutionised the concept of personalised treatment for better management of the disease and thus marked the beginning of the era of Precision Medicine.