RESUMEN
<p><b>OBJECTIVE</b>To evaluate the value of serum prostate specific antigen (PSA), free PSA (FPSA) and PSA density (PSAD) in early diagnosis of prostatic cancer.</p><p><b>METHODS</b>Sixty-eight patients with benign prostate hyperplasia (BPH), 28 with prostatic intraepithelial neoplasia (PIN) without canceration, and 32 with prostatic cancer, all diagnosed by prostatic biopsy, were enrolled in this study. Serum PSA and FPSA were measured and FPSA/PSA ratio and PSAD calculated for each patient, and the data analyzed to explore the association of these indices with prostatic cancer.</p><p><b>RESULTS</b>Serum PSA level and PSAD were markedly different between the cancer patients and non-cancer patients (P<0.001 and P<0.01, respectively). FPSA/PSA ratio also differed between them (P<0.05). The same results were also found between BPH and cancer patients. Significant difference was noted in serum PSA and PSAD between PIN and cancer patients (P<0.01), but not in FPSA/PSA ratio (P>0.05). No marked difference was observed in serum PSA, FPSA/PSA ratio and PSAD between BPH and PIN patients.</p><p><b>CONCLUSION</b>Serum PSA provides a very important clue for early diagnosis of prostatic cancer, and more accurate diagnosis can be obtained by considering also FPSA/PSA ratio. PSAD may also assist in the early diagnosis of prostatic cancer.</p>