GP5 and cancer: GP5 has evidenced validity: using multiple datasets compiled from clinical trials and prospective observational studies that included patients with multiple cancer sites; Pearman and colleagues found that (1) the mean GP5 response increased with adverse event (AE) toxicity grade; (2) the number of AEs experienced increased monotonically with worsening responses to GP5; and (3) HRQoL, as measured by the EuroQol-5 dimension (EQ-5D), decreased monotonically with worsening responses to GP5 [15].