[Evaluation and diagnosis for castration resistant prostate cancer: CRPC]

When considering the diagnosis of castration resistant prostate cancer (CRPC), one of the possible approaches consists of performing examination and diagnosis to determine the presence of CRPC. The definition of CRPC is simple-disease progression despite a serum testosterone value below 50 ng/dL after androgen deprivation therapy (ADT). It is similar to an earlier definition--"an initial relapse" occurring after primary ADT. Therefore, it is important to determine the histopathological type of CRPC to establish a course of treatment thereafter. Regarding the "examinations" and "diagnosis" for the staging of CRPC, it is likely that the circulating tumor cell assay and quantitative imaging examinations will be needed, instead of bone scintigraphy, in the future.