Serum gamma-seminoprotein determination in prostatic cancer.

Serum gamma-seminoprotein (gamma-Sm) was evaluated as a new marker for prostatic cancer in comparison with prostatic acid phosphatase (PAP). The sensitivity of gamma-Sm and PAP for untreated prostatic cancer was 81% and 67%, respectively. gamma-Sm showed a higher positive rate over all stages than in benign prostatic hypertrophy (BPH). There was no correlation between gamma-Sm and PAP in prostatic cancer. Improved sensitivity was obtained by simultaneous measurement of gamma-Sm and PAP. Specificity of gamma-Sm and PAP for BPH was 87% and 90%, respectively. gamma-Sm normalized after endocrine therapy for stage D2 more often than did PAP. These results indicate that gamma-Sm is another useful marker to evaluate prostatic cancer.