A prognostic biomarker classically identifies patients with differing risks of a specific outcome, such progression or death [25, 26]. Recently, the prognostic biomarker was defined as a single trait or signature of traits that separates a population with respect to the outcome of interest, regardless of the types of therapies or treatments [27]. For example, under this description, if a particular biomarker were prognostic, the result (clinical response) of patients with biomarker-positive status would be improved than that of patients with biomarker-negative status in both the test and standard treatments. The prognostic biomarker can decide populations into groups whose result will be poor or good following the test and standard treatments,
