Serum levels of endothelial and neural cell adhesion molecules in prostate cancer

BACKGROUND. Tumorigenesis and progression to metastatic disease are accompanied by changes in the expression of cell adhesion molecules (CAMs). Normally expressed CAMs, such as E-cadherin, are lost, while others, i.e., ICAM-1, VCAM-1, NCAM, and E-selectin, are altered and overexpressed in progressive disease and metastases. Abnormal levels of these latter CAMs have been observed in melanoma and carcinomas of the colon and breast, and NCAM is overexpressed in small-cell lung carcinoma (SCLC). The objective of this study was to determine if serum levels of ICAM-1, VCAM-1, NCAM, and E- selectin could differentiate patients with benign prostate hypertrophy (BPH) from those with prostate carcinoma (CAP) and identify prostate cancers with high potential for progression to metastatic disease. METHODS. Serum levels of these CAMs were determined by ELISA in serum from normal males and females and from patients with BPH and CaP before and after treatment. Sera from patients with breast carcinoma, colon carcinoma, melanoma, and small-cell lung carcinoma were also evaluated, as soluble CAMs have been reported to be elevated in these cancer patients. RESULTS. ICAM-1 levels were elevated in sera from patients with breast carcinoma (P = 0.0004) and melanoma (P = 0.0001). VCAM-1 levels were elevated in sera from patients with colon carcinoma (P = 0.0001). NCAM levels were elevated in the sera of patients with SCLC (P = 0.0001). Normal levels of ICAM-1, E-selectin, and NCAM were found in both BPH and pretreatment CaP patients. Median NCAM levels in hormone-refractive CaP patients were significantly greater than in BPH (P = 0.0005) and CaP patients with pathologically determined organ-confined (P = 0.0014) or nonorgan-confined disease (P = 0.0385). VCAM-1 levels were significantly elevated in both BPH patients (P = 0.0002) and CaP patients (P = 0.0002) when compared with levels for normal age-matched donors. None of the CAMs were found to offer an advantage over prostatic-specific antigen (PSA) for monitoring CaP patients following definitive radiotherapy, radical prostatectomy, or hormonal therapy. CONCLUSIONS. The results of this study indicate that serum ICAM-1, VCAM-1, NCAM, and E-selectin are not clinically useful biomarkers for differentiating CaP from BPH, for predicting progression, for identifying metastatic potential, or for monitoring treatment.