Presence of prostate cells in bone marrow biopsies as a sign of micrometastasis in cancer patients.

The presence of prostate cancer cells in bone marrow of patients with clinically localized disease is associated with increased chance of disease recurrence. The presence of prostate specific antigen (PSA) in bone marrow aspirates has been used to indicate the presence of micrometastasis. The aim of this study was to present a prospective study of prostate cancer patients to determine the presence of cells that express PSA in aspirates taken from bone marrow and to compare with bone marrow biopsy samples. Results indicated a significant difference between the frequency of cells detected in bone marrow aspirate and biopsy samples (P<0.0002) when all patients were considered. There was no difference between the frequencies of cells detected in bone marrow aspirate and biopsy of patients analyzed before treatment. However, there was a significant (P<0.003) difference between them after treatment. There was also a significant difference in the frequency of PSA positive cells detected (P<0.005) in Stages I to IV as well as in the frequency of cells detected (P<0.0002) when analyzed according to Gleason score. The present results explain the lack of correlation between positive aspirates and prognosis in numerous clinical cases.