The pattern of serum markers in patients with androgen-independent adenocarcinoma of the prostate

In this exploratory study, our objectives were to correlate the serum and b one marrow concentrations of putative markers of prostate cancer progressio n in patients with advanced androgen-independent prostate cancer (AIPC), to assess the frequency and quantity of relative expression of these markers, and to correlate the expression of the markers with extent of disease (EOD ) and overall survival. In a cohort of 50 patients with AIPC with bone meta stases, we obtained serum and bone marrow samples and measured prostate spe cific antigen (PSA), serum interleukin-6 (sIL-6), bone marrow interleukin-6 , serum chromogranin A (sCgA), bone marrow chromogranin A, and prostate spe cific membrane antigen (PSMA) by immunoassays. EOD was determined by quanti fying identifiable bone lesions on radionuclide bone scans. Each variable w as categorized into two groups (low and high) based on the median found in this cohort or on the cutoff based on normal limits when available. Analyse s were performed in two subsets of patients with EOD either <20 or greater than or equal to 20. Results showed that: (1) PSA is associated with EOD bu t not with outcome; (2) sIL-6 and sCgA may be intermediate markers of early progression in AIPC, because they are predictive of outcome only in patien ts with EOD <20; (3) elevated PSMA is associated with elevated sIL-6 but no t with PSA, suggesting that PSMA may be a useful marker in AIPC; and (4) th e ratio of PSA to putative markers of progression may reflect the complex c lonal progression of prostate cancer. We conclude that patients with advanc ed AIPC exhibit one of two patterns of serologic marker expression: in some patients the disease status is reflected by PSA, and in others it is refle cted by other markers. If these data are prospectively confirmed, this woul d help group patients with advanced AIPC into clinically relevant categorie s. (C) 2000 Elsevier Science Inc, All rights reserved.