Liquid Biopsies, the Future of Cancer Diagnostics.

Globally, nearly 1 in 6 people die from cancer. In 2015 alone, the disease was responsible for 8.8 million deaths – the equivalent of the entire population of London.

The traditional method of diagnosing cancer has been through a tissue biopsy – a difficult, invasive procedure which involves surgery to extract a tissue sample from the patient. This sample is subsequently tested to see if cancer is present or how it is developing.

Tissue biopsies are slow and costly procedures – they take up the time of surgeons and fill hospital beds all over the world, which is why the introduction of liquid biopsies – analysing the status of cancer via a blood test or similar, has had such an impact.

Monitoring Cancer

Performing multiple tissue biopsies is traumatic for the patient and costly for medical professionals. This means that even the least invasive tissue biopsy can’t be performed on a regular basis.

Liquid biopsies, on the other hand, can be administered more frequently, which means that certain cancers can now be more closely monitored than ever before.

Exosome are one company making this happen. They offer two liquid biopsies which monitor exosomal RNA and circulating tissue DNA (ctDNA) samples, monitoring the aggressiveness of lung and prostate cancer.

This form of monitoring is really useful – rather than just being able to say ‘yes’ or ‘no’ when it comes to a cancer diagnosis – companies can now say what the cancer is doing, and we’re a lot closer to also saying why it is developing in a certain way.

Genomic tests can also be performed on liquid biopsy samples. Two big competitors in this area are Guardant and Foundation Medicine. They work with blood draws from the patient, looking to analyse genomic differences in solid tumours that could help with treatment.

This form of genomic testing - analysing the building blocks of a solid-state tumour - is particularly useful for more advanced cancers, something which both these companies specialise in. This is explained well on Guardant’s website:

“Some genomic alterations are known to respond better to specific therapies. Guardant360 looks for all these clinically relevant alterations, giving your doctors the opportunity to tailor treatment to your cancer.”

Biodesix utilise both genomic and proteomic tests with their liquid biopsies – which also allows for effective patient monitoring, allowing for the recording of both tumour mutations and the impact of the patient’s own immune response to the tumour. In addition to analysing the building blocks of the treatment, the addition of proteomics also allows Biodesix to track the real-time changes taking place within the proteins of the patient. These proteins give structure, send signals and turn food into energy within the body, so monitoring changes within them can offer a great insight into how a condition is progressing.

Predicting Cancer

Liquid biopsies are great for monitoring patients who are already diagnosed with cancer, but the aim for everyone working in the industry is to find a test which can accurately diagnose cancer in previously asymptomatic patients.

In January 2018, an ‘enormously exciting’ development in cancer diagnostics made global headlines.

The CancerSEEK test looks for both ctDNA and proteomic changes – leading to it being able to find 70% of 8 types of cancer in more than 1,000 patients – a potentially major step to finding and stopping cancer much earlier.

One company hoping that they are close to finding a solution to this problem is Cellmax Life. Their test, which is already commercialised in Taiwan, specialises in testing for colorectal and prostate cancers in ‘healthy’ patients. They’re entering US testing in 2018 and are a really exciting company to look out for.

GRAIL are probably the most aptly named company pursuing the ‘holy grail’ of a cheap and universally applicable test which can diagnose a range of cancers in asymptomatic patients. With high profile investors including Bill Gates, Amazon and Google, they’ve been making serious waves in the space.

With backers including Bill Gates, Amazon and Google but with little data available about their progress they are another company that the whole industry will be watching.

Image from grail.com

With such high profile supporters and continued R&D spend in this area, the capabilities of liquid biopsies in the diagnosis, monitoring and treatment of cancer will only improve. Whilst they might not be common practice in hospitals today, at the current rate of progress it’s not an understatement to say that liquid biopsies could revolutionise the way in which we diagnose, mo