Combined serum and bone marrow radioimmunoassays for prostatic acid phosphatase.

Combined serum and bone marrow radioimmunoassays for prostatic acid phosphatase provide a unique means for the early diagnosis and more accurate clinical staging of prostatic cancer. The combined screening technique appears to be helpful, particularly in providing a clinical assessment of the presence or absence of early, subclinical lymphatic and bone marrow metastases. Low titer elevations of bone marrow prostatic acid phosphatase by radioimmunoassay have been observed commonly in clinically understaged C prostatic cancer with normal technetium bone scans, indicating the presence of unrecognized stage D disease with bone metastases. The combined screening method also is of distinct clinical value in the early diagnosis of prostatic cancer and in monitoring the effects of specific therapy. In therapeutically responsive patients marked suppression of serum and bone marrow prostatic acid phosphatase is observed regularly with the radioimmunochemical method under study.