Reproducing the normal and the pathological in personalized cancer medicine clinical trials

The medical practice termed Personalized Medicine ideally uses all the patient’s possible characteristics in predicting disease predisposition and response to therapy, but primarily employs the individual’s unique molecular make-up in the tailoring of treatment. This change in medical practice also entails an epistemic shift towards ‘molecularization’: individuals and disease are now understood and governed through life’s basic building blocks. In this paper we argue that underlying personalized medicine is a continued understanding of the pathological state as a quantitative deviation from a normal state. In this we build on the critique of French philosopher Georges Canguilhem who positioned the quantitative interpretation of the pathological in nineteenth century medical thinking. Personalized cancer medicine takes each patient’s cancer as singular, implying that there is no ‘normal’ baseline for comparing individual pathology. We analyze cases of personalized cancer clinical trials from recent years to show that each displays a quantitative understanding of the pathological reminiscent of past thinking in two main modes: a molecularized interpretation of cancer pathology and a quantitative measuring of targeted therapy efficacy. We situate the analysis in broader discussions of historical medical shifts and in current studies of personalized medicine, to outline implications of this form of continuity.