On the cusp: from evolution to revolution
The clinical management of cancer patients has undergone a remarkable evolution in the past decade, with the concept of personalized medicine now well-entrenched in the treatment paradigm of a significant number of tumor types. Whereas treatment decisions used to rely on a combination of clinical observations, various macro-imaging techniques and general histopathological findings, oncologists now have a range of biomarker tests at their disposal to make a more informed drug choice.
Phase change: from solids to liquids
As innovative and promising as the tests detailed in the attached file are, despite the radically different sample requirements, they still represent a fundamentally unchanged approach in terms of what markers are being tested: each of the tests listed above looks for mutations/changes in expression levels of single genes or proteins (though some commercial laboratories allow for multiple individual markers to be requested at the same time, provided there is enough liquid in the sample).
Strength in numbers: from single-marker tests to pan-cancer testing panels
The inherent limitations of single-marker tests are two-fold:
- Genes do not act in isolation.
- Not all cancers exhibit mutations commonly found in that cancer type
More recently, several companies have launched and marketed commercial testing panels as integrated solutions: doctors are able to send samples for analysis to those companies’ dedicated laboratories, and will receive - often very detailed - reports on the genetic characteristics of the tumor, complete with treatment and/or clinical trial recommendations.
The sum of the parts: liquid pan-cancer testing panels
The two major new developments described in the attached file – clinically useful liquid biopsies and pan-cancer testing panels – arrived on the scene at around the same time. Several diagnostics companies sensed a real opportunity here, and started working on products that sat squarely at the center of where those two new technologies converged: pan-cancer testing panels based on liquid biopsies. The theory behind them is remarkably elegant: if circulating tumor DNA (or ctRNA) can be detected in a cancer patient’s blood, and if tumor DNA can be used to conduct pan-cancer testing panels, then a cancer patient’s blood should be a viable sample type for conducting such large multi-gene panels.
Looking ahead: the coming molecular intelligence revolution
While immensely useful from a clinical perspective, the approach is far from perfect, due to a number of fundamental limitations:
- Cancer cells are in a constant state of flux
- Genes do not act in isolation
- Even the most well-trained pathologists or oncologists are limited by the amount of information they can process
- Biomarker testing – whether single marker or multi-gene, whether tissue-based or liquid-based – is currently reactive
Three major areas of research are likely to make a significant impact:
- Labs on a chip, with remarkable sensitivities
- Continuous improvements in the cost, speed and reliability
- Perhaps most significantly, the inexorable rise of Artificial Intelligence