Levels of circulating intercellular adhesion molecule-1 in patients with metastatic cancer of the prostate and benign prostatic hyperplasia

Abstract

Current reports suggest a role for intercellular adhesion molecule-1 (ICAM-1) in the progression of malignancy. The availability of a new antibody makes it possible to measure circulating ICAM-1 (cICAM-1) in human body fluids including serum; this might help in monitoring tumour burden and in providing additional prognostic information. In this study, serum levels of cICAM-1 were measured by an ELISA assay in patients with benign prostatic hyperplasia (BPH; n = 20) and metastatic cancer of the prostate (CaP; n = 25). Serum ICAM-1 concentrations were also measured in a group of healthy men (n = 8). The mean +/- S.E.M. cICAM-1 level for BPH was 339.52 +/- 15.30 ng/ml compared with 263.55 +/- 18.54 ng/ml for CaP. Even though the difference between the two groups was significant (P < 0.005), there was a marked overlap between the individual values in both groups, thus minimising the prognostic value of these measurements in prostate cancer. Endocrine therapy had no notable effect on the serum levels of cICAM-1. The mean +/- S.E.M. cICAM-1 concentrations in serum from a younger group of healthy volunteers was 204.1 +/- 10.38 ng/ml, and this value was significantly lower than that measured in serum from either BPH or CaP. We also undertook some immunohistochemical studies to examine the distribution of ICAM-1 in prostate tissue. We observed focal epithelial cell membrane staining which was exceedingly patchy in both the BPH and cancer specimens. On the basis of these studies, we suggest that cICAM-1 levels do not provide additional information on patients with metastatic CaP.