1987 Volume 78 Issue 5 Pages 844-852
An immunoassay for the prostate specific antigen (PA) has been reported to be useful for detecting the early stage of prostatic carcinoma and for monitoring its clinical courses.
We evaluated the clinical significance of PA in prostatic carcinoma measured by radioimmunoassay.
We determined 3.0ng/ml as the upper normal limit, since forty-one healthy males showed serum PA level of 2.46±0.36ng/ml (mean±S. D.).
Serum PA level of BPH patients was 4.33±2.69ng/ml (mean±S. D.) which was statistically higher than that of healthy males or of non prostatic disease patients. This result provided 10.0ng/ml of serum PA level as the upper limit in this disease.
Serum PA in prostatic carcinoma tended to increase as the clinical stage progressed. PA level of stage D was statistically higher than that of stages A, B or C (p<0.05). When 10.0ng/ml was regarded as the upper limit of BPH, the positive rate of PA in each stage was 0% in stage A, 55.5% in B, 40.0% in C and 73.1% in D. The positive rate exceeding 50% in stage B suggested thet PA determination could detect more patients with early stage cancer (stage B) than PAP did. And the simultaneous determination of PAP which is routinely measured, and PA could be more clinically useful since PAP negative but PA positve patients were found in 44.4% of them in stage B.
Furthermore, the level of PA determined during the follow-up reflected the patients' clinical status, suggesting that the determination of PA is useful for monitoring the clinical course of patients.
Serum PA level was correlated to that of PAP (r=0.66), but the correlation tended to be small, when the level of PA was near or below 10.0ng/ml.
The definite correlation was not found between the level of PA and the histopathological differentiation of prostatic carcinoma. Nor was any correlation observed between the level of serum PA and androgen receptor contents in the cytosol of prostatic carcinoma. These results may imply that the level of PA reflects the biological aspect of carcinoma different from the tumor differentiation and androgen receptor content.
