The race to perfect the liquid biopsy

Precision medicine alongside liquid biopsy brings us closer than ever to revolutionising the management of lung cancer.

Lung cancer has the highest global mortality rates of all cancers, due to the fact that many cases are only detected at advanced stages of disease. Whilst lung cancer grows more prevalent than ever, we are seeing increasing development in precision medicine techniques and non-invasive methods of obtaining samples such as liquid biopsy. 85% of lung cancers are classified as non-small cell lung cancer. Ultimately treatments are similar across 3 sub-types, however research suggests varying responses to drug treatment due to differing genetic characteristics.

Liquid biopsies would revolutionise cancer care

Currently, we use imaging techniques such as CT scans, MRIs and X-rays, followed by surgical biopsies to detect and diagnose tumours. Liquid biopsies refer to blood tests that analyse circulating tumour debris, shed into the blood, as an alternative to tumour biopsies which are more invasive. Scientists can use highly sensitive genetic techniques in tandem with liquid biopsy, such as Next Generation Sequencing (NGS). This is a powerful, high-throughput genetic sequencing technology;  such methods allow us to detect of cancers and dictate tailored treatments, saving lives and preventing reoccurrence.

Using liquid biopsy alongside genomic profiling techniques such as NGS, means we can easily access and profile genetic material and identify specific gene mutations. This will allow us to choose a tailored treatment which is more effective for the specific cancer and hence drastically improve the success of the treatment. With real time genetic information (facilitated by liquid biopsy) regarding the molecular characteristics of the disease, we can apply targeted, novel treatments which act on mutated (cancer) cells unlike older treatments which may destroy healthy cells in their path. Not only would this mean more positive treatment outcomes, but also provide the patient with a better quality of life due to the ease of sampling blood and serial repeats for real-time monitoring. Therefore, liquid biopsies would revolutionise cancer care on multiple fronts. 

Liquid biopsy is right on the cusp of starting a revolution

It is estimated that up to 55% of people with non-small cell lung cancer may experience recurrence of disease. This can be due to small groups of residual cancer cells which are too small to be seen on scans.  However, as the sensitivity of the genetic tests improve, we may be able to detect the remaining cells in the blood and treat people ahead of symptom presentation before the cells can proliferate again.

Revolutionising the management of lung cancer would involve drastically improving long term survival through detection, treatment, monitoring, and preventing recurrence through detecting relapse and resistance genotyping. It is certainly conceivable that liquid biopsy, combined with techniques such as NGS may facilitate this revolution. However, for widespread clinical use, the optimisation of test sensitivity and extraction techniques must be achieved to justify the replacement of established methods. More research is needed to determine these facts and it’s constantly accelerating. Only then, with the correct validation and facilities can we use the liquid biopsy to its full capacity. Glimmers of the future have already been seen in the FDA approval of the companion diagnostic Guardant360 CDx for osimertinib: testing patient eligibility based specific biomarkers. Oncologists have already deemed this as completely transformational for this group of patients in delivering highly precise and effective treatments. An interview with a precision oncologist revealed that, “liquid biopsy is right on the cusp of starting a revolution”, and the case is not “if” we will see results, but “when”.