Metastatic prostate cancer with normal level of serum prostate-specific antigen

The clinical and pathologicalfeatures of metastatic prostate cancer withnormal level of serum prostate-specific antigen(PSA) were investigated. Four patients withmetastatic prostate cancer had serum PSA withinthe normal range at the diagnosis. All tumorswere poorly-differentiated adenocarcinoma. Endocrine therapy was performed as the initialtherapy in all patients. Despite subsequentlytreatment, all cases died of prostate cancer at2, 8, 9 and 38 months. During diseaseprogression, 3 of 4 patients had elevated serummarkers such as carcinoembryonic antigen (CEA),CA19-9, CA15-3, CA125, neuron-specific enolaseand pro-gastrin releasing peptide. Immunohistochemical examination of the initialbiopsy specimens revealed that 4 and 3 caseswere positive for CEA and chromogranin A,respectively. In advanced prostatecancer patients with low PSA level, thosemarkers may aid in the follow up of disease.