The Evolution of Affordable Technologies in Liquid Biopsy Diagnostics: The Key to Clinical Implementation

SIMPLE SUMMARY: This review aims to highlight the usage of circulating tumour DNA and circulating tumour cells in various manners for the care of cancer patients. The different technologies that are currently employed using these biomarkers are mentioned and contrasted with another whilst also discussing their limitations such as affordability and scalability. The review also aims to bring light to newer emerging technologies in the space of liquid biopsy that have yet to be approved by a regulatory board but have been developed with the notion of affordability and scalability in mind. These factors of technology are found to be important in order to provide cutting edge diagnostic and monitoring regimes as they can lead to personalised treatments and patient stratification for all. ABSTRACT: Cancer remains a leading cause of death worldwide, despite many advances in diagnosis and treatment. Precision medicine has been a key area of focus, with research providing insights and progress in helping to lower cancer mortality through better patient stratification for therapies and more precise diagnostic techniques. However, unequal access to cancer care is still a global concern, with many patients having limited access to diagnostic tests and treatment regimens. Noninvasive liquid biopsy (LB) technology can determine tumour-specific molecular alterations in peripheral samples. This allows clinicians to infer knowledge at a DNA or cellular level, which can be used to screen individuals with high cancer risk, personalize treatments, monitor treatment response, and detect metastasis early. As scientific understanding of cancer pathology increases, LB technologies that utilize circulating tumour DNA (ctDNA) and circulating tumour cells (CTCs) have evolved over the course of research. These technologies incorporate tumour-specific markers into molecular testing platforms. For clinical translation and maximum patient benefit at a wider scale, the accuracy, accessibility, and affordability of LB tests need to be prioritized and compared with gold standard methodologies in current use. In this review, we highlight the range of technologies in LB diagnostics and discuss the future prospects of LB through the anticipated evolution of current technologies and the integration of emerging and novel ones. This could potentially allow a more cost-effective model of cancer care to be widely adopted.