Diagnosing Cancer from a Drop of Blood
Pagel, K. – 2022
Cancer is the plague of our time. It is the leading cause of death worldwide, accounting for nearly one in six deaths. The mortality of cancer is reduced significantly when diagnosed and treated early enough, ideally before or immediately after the first symptoms occur. The current gold standard in cancer diagnostics are biopsies from suspect tissue, which are examined using histology. However, the excision of specimen is often a very unpleasant and painful experience for the patient and potentially suffers from sampling inaccuracy due to tissue inhomogeneity. An alternative strategy are so-called liquid biopsies: the sampling of circulating or excreted body fluids such as blood or saliva, which are subsequently screened for specific DNA or protein-based tumor markers using immune recognition or sequencing techniques. A limiting factor of this approach is that each molecular probe is sensitive to only one particular feature, which may not be sufficient to come to a reliable conclusion. Multiplexing the detection of multiple DNA and protein-based features is generally possible, but causes further problems such as cross-reactivity and exploding costs.