Since the development of microarray technologies, there has been significant investment in the potential for gene-expression profiling to drive innovation in clinical diagnostics and therapy. Now, twenty years since the first prototype was developed, we assess the impact on clinical management of cancer patients through new diagnostic tools and treatment strategies developed as a result of this technology, and present a perspective to both the limitations and future promise of molecular profiling in the clinic.

The beginnings of the microarray revolution

The origins of DNA microarray technology date back to the late 1980s, when Stephen P.A. Fodor pioneered the first microarray system, the Affymetrix GeneChip® (Figure 89.1; 1). With Affymetrix commencing commercial sales of the GeneChip® system for research use in 1994, and the publication in 1995 by Patrick Brown and colleagues at Stanford University assessing gene expression in Arabidopsis thaliana, the research landscape was changed irrevocably (2). While Affymetrix continued to dominate the field, the Human Genome Initiative provided the impetus for researchers to actively pursue development of alternative types of DNA microarrays, with many other platforms entering the arena (3). By the mid-1990s, microarray technology had moved from a boutique technology to an integral component of the medical research toolbox and was responsible for attracting major investment into the biotechnology and pharmaceutical sector with the focus firmly on understanding the molecular basis of human disease and informing treatment decisions.