Circulating biomarkers in cancer care: what possible use?

The practice of the physician has changed greatly in the last 100 years. Yet, the fundamental role remains constant: it is the physician's function to make a diagnosis, assess prognosis, choose and deliver the most effective treatment and then to assess the adequacy of that treatment (both in terms of effectiveness and safety). Whereas our predecessors were almost entirely reliant on clinical history and examination findings in conducting these assessments, the 21st century physician is aided by a plethora of blood tests, imaging investigations, electrophysiological recordings and morphological and molecular analyses of tissue samples. For many patients, the totality of these newer tests contributes relatively little to their journey, whilst, for some, key tests can dictate the direction of travel and, sometimes, the ultimate destination