HER2 Revisited: Reflections on the Future of Cancer Biomarker Research

Abstract

AbstractIn this chapter, we revisit the successful story of the HER2 biomarker for breast cancer, to reflect on the conditions of its inception, some of the reasons for its success, and the challenges met along the way. HER2 is a standard in the field of cancer biomarker research, against which all biomarkers are measured. It is also one of the central arguments used for illustrating the feasibility and desirability of precision oncology. But critically revisiting the story of HER2 shows us that it too faced a winding road from its discovery in the lab to its use in the clinic, and that it currently operates in a context of high levels of biological complexity and persistent uncertainties, in particular with regard to cancer heterogeneity and its implications. By drawing a parallel between the story of HER2 and a ‘scientific bandwagon’, we examine some of the legal, social, and economic challenges and dilemmas that HER2 faces, and conclude with some reflections on the future of cancer biomarker research. Notably, we highlight the need for a greater focus on ‘good enough’ biomarkers, particularly in the setting of precision oncology driven by hyper-precision and the wish for molecular certainty. We emphasise the importance of being open about the low success rate of 1% of published biomarkers which reach clinical practice when justifying the risks and opportunity costs of precision oncology.