The value of gamma-seminoprotein in combination with prostate specific antigen in detecting prostate cancer.
BACKGROUND
The present study was undertaken to investigate the value of gamma-seminoprotein (gamma-Sm) and the gamma-Sm/prostate specific antigen (PSA) ratio in combination with serum PSA in detecting prostate cancer.


METHODS
Prostate specific antigen, gamma-Sm and the gamma-Sm/PSA ratio were evaluated in 112 patients with untreated prostate cancer and 90 patients without prostate cancer who had serum PSA and gamma-Sm levels above their respective detection limits.


RESULTS
When data for all of the patients were analyzed, serum PSA and gamma-Sm levels were significantly higher and the gamma-Sm/PSA ratio was significantly lower in patients with prostate cancer than patients without prostate cancer. The serum PSA and gamma-Sm levels significantly increased and the gamma-Sm/PSA ratio significantly decreased with advancing clinical stage in patients with prostate cancer. Among the patients with serum PSA levels ranging from 1.8 to 6 ng/mL, the gamma-Sm/PSA ratio was significantly lower (P < 0.05) and gamma-Sm levels were lower (P = 0.054) in the patients with prostate cancer than in those without prostate cancer, but serum PSA levels were not significantly different (P = 0.53). A receiver operating characteristic (ROC) analysis demonstrated that the areas under the ROC curves were 0.54 for PSA, 0.65 for gamma-Sm and 0.69 for the gamma-Sm/PSA ratio for prediction of prostate cancer in the PSA range from 1.8 to 6 ng/mL, although the ROC analysis suggested that the gamma-Sm/PSA ratio does not provide significant advantage over PSA in detecting prostate cancer when all of the patients were analyzed.


CONCLUSIONS
These results suggest that the gamma-Sm/PSA ratio and gamma-Sm may facilitate differentiation between patients with and without prostate cancer who have intermediate PSA levels.
Department of Urology, Keio University School of Medicine, Tokyo, Japan.
J
J
Nakashima
H
H
Nagata
M
M
Sumitomo
A
A
Miyajima
M
M
Tachibana
S
S
Baba
S
S
Jitsukawa
M
M
Murai
D000230:Adenocarcinoma / Q000097:blood* / Q000175:diagnosis; D019540:Area Under Curve; D014408:Biomarkers, Tumor / Q000097:blood*; D006801:Humans; D008297:Male; D011237:Predictive Value of Tests; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D012372:ROC Curve; D012680:Sensitivity and Specificity
D014408:Biomarkers, Tumor; D017430:Prostate-Specific Antigen