After administering a therapy with curative intent, patients and physicians have 1 key question in mind: is the cancer cured? Unfortunately, because of the limitations of our current standard of surveillance, we can never be sure that all the tumor cells have been eradicated and therefore never be sure of a cure. An implication of this view is that even patients who have responded to treatment still need posttherapy prognostic factors to predict the patient’s outcome after treatment.