Invasion of non-invasion in diagnostics

Medicine has been changing rapidly with the application of In Vitro Diagnostics (IVD) and this change can be greatly seen with the availability of a slew of new diagnostic tests. Most of us think of imaging tests such as x-ray, CT (computerised tomography) scans and MRI (magnetic resonance imaging) which seem to be the common non-invasive tests presently available. Yet as efficient as imaging is they have limited application in deciphering the constitutional makeup at a cellular level.

 

Applications in cancer

The biggest fear factor for anyone who needs to check if they have cancerous tissues is the biopsy process itself. Not only is the process of going through a biopsy stressful, the biopsy tissue itself is a cross section of only a segment of the tumour, hence multiple biopsies are usually done. To make it even more challenging invasive biopsies can be done recurrently to check the status of disease progression. In advanced disease states with multiple sites finding the composition of the tumour would be another challenge. 

Fast forward to the present and there is a radical change in what is available now – the liquid biopsy. This is a simple blood test which can tell you at the cellular level if you have cancer even at early stages, furthermore it can give you the profile of the tumour so that precision chemotherapy can be administered if needed. This is based on the principle of circulating cells which is released by the tumour in the body. These cells can be identified based on their structural makeup and hence a definite diagnosis and treatment is possible. The most beneficial aspect about this type of technology is the precision and ease of use. 

Recently Guardant Health announced their 70 gene liquid biopsy study which showed a concurrence of 87% with normal solid tumour biopsies. This has many implications in healthcare. The most prominent would be the ability of a single test to be able to do what multiple biopsies would have done significantly reducing patient discomfort and over a period of time costs. 

Applications in obstetrics

Cancer is not the only area where this type of technology is being applied. Even in obstetrics, non-invasive pre-natal testing has started changing the paradigm especially in high risk mothers. Earlier a high risk mother following evaluation would undergo a scan and if at risk would have an amniocentesis (Amniotic Fluid Test). This would usually be done after the 14th to 16th week and carries a risk to the unborn child. The risk of miscarriage when doing this invasive procedure would be anywhere between 2% – 6% and would require considerable skill to do. Now the presence of non-invasive prenatal testing allows for a high risk individual to check all of these risks with a simple blood test. After the 10th week the foetal blood cell can be detected circulating in the blood supply of the mother and using a special technique is separated for identification. Once separate the baby’s DNA can be scanned with over 95% accuracy for Down’s syndrome and other common chromosomal birth defects without conducting any risky procedures.  Further analysis can reveal other inherited disorders which the child could be predisposed too.

 

Future applications

This is just the tip of the iceberg in terms of what can be offered. As technology improves offerings in diagnostics will also be plentiful. Of course since most of the applications that are being developed will be new and unique clinical utility will have to be integrated with protocols. What can be noticed however with these early applications is the presence of such tests will change how clinicians and patients respond to treatment and care. Clinical diagnostics continues to disrupt at a rapid rate paving the way for radical changes in clinical care bringing a positive outcome to all stakeholders involved.