Wang J, Xu W, Mierxiati A, et al. - A total of 449 individuals with neuroendocrine prostate cancer (NEPC), including 352 cases of pure NEPC and 97 cases of neuroendocrine (NE) differentiation, together with 408,629 cases of prostate adenocarcinoma at diagnosis were reclaimed from the Surveillance, Epidemiology, and End Results program (2010-2015) by the researchers in order to elucidate the clinical features of the primary NEPC and primary adenocarcinoma with NE differentiation. In comparison with NE differentiation and prostate adenocarcinoma, pure NEPC had greater rates of visceral metastases but a lower rate of bone metastasis. Furthermore, individuals diagnosed with pure NEPC vs individuals with NE differentiation and prostate adenocarcinoma had a poorer outcome. The adjusted HRs for prostate-specific antigen (PSA) lower than or equal to 4.0 ng/mL were 2.24 and 1.57 in the NE differentiation group and in the pure NEPC group, respectively, using PSA 4.1 to 10 ng/mL as the reference. Hence, individuals with NE differentiation had various clinical features and a better prognosis as that of individuals with pure NEPC. Moreover, in individuals with either NEPC or NE differentiation, low-serum PSA levels were correlated with a poorer prognosis.