Assessment of serum radioimmune and enzymatic prostatic acid phosphatase and radioimmune creatine kinase BB for monitoring response to therapy in metastatic prostatic carcinoma.
Objective documentation of tumor response in patients with metastatic prostatic cancer is difficult. To evaluate a radioimmunoassay for creatine kinase BB, two commercial radioimmunoassays for prostatic acid phosphatase, and an enzymatic acid phosphatase measurement in monitoring the status of advanced prostatic carcinoma, we assayed sera from 34 patients with Stage D-2 disease prior to and during systemic treatment with combination chemotherapy or hormonal manipulation. Prior to treatment, the creatine kinase BB level was elevated less often (48%) than all three assays for acid phosphatase (83 to 91%). During therapy, all four test results both increased and decreased whether the patients were responding to or progressing on therapy. Test results usually declined when patients had documented responses to therapy, particularly when hormonal therapy was used. However, when patients progressed on therapy, test results also declined at least as often as they increased. No test was consistent enough to serve as a sole indication of tumor response. The three acid phosphatase assays performed similarly, with no evident advantage of radioimmunoassay over the enzymatic assay. Creatine kinase BB was generally inferior to all three acid phosphatase assays.
D000135:Acid Phosphatase / Q000097:blood*; D003402:Creatine Kinase / Q000097:blood*; D006801:Humans; D007124:Immunoenzyme Techniques; D008297:Male; D008991:Monitoring, Physiologic / Q000379:methods*; D011467:Prostate / Q000201:enzymology*; D011471:Prostatic Neoplasms / Q000201:enzymology* / Q000628:therapy; D011863:Radioimmunoassay
D003402:Creatine Kinase; D000135:Acid Phosphatase