Next-Generation Screening for Colorectal Cancer, an Incremental Approach to a Global Disease

New screening tests for early detection of colorectal cancer and its precursors are rapidly emerging with the focus on noninvasive tests which can be used in both structured opportunistic and population-based organized screening programs. Novel technologies are identifying new combinations of promising markers. Conducting large prospective clinical trials of efficacy requires very large numbers of subjects constituting intended-use populations. These trials are often preceded by studies using smaller numbers of "convenience"samples to derive panels of relevantmarkers and algorithms to combine themand define what constitutes a positive test. The article by Gagrat and colleagues in this issue reports results from one such study designed to yield a "next-generation"multitargeted (mt-sDNA) stool test. This report exemplifies the advantages and limitations of this approach.