Serum keratinocyte growth factor measurement in patients with prostate cancer

PURPOSE: Keratinocyte growth factor (KGF) is a stromally derived growth factor important in mediating androgen induced activities in benign prostatic hyperplasia (BPH) and prostate cancer. We assessed whether serum KGF could be used as a molecular marker in patients with prostate cancer. MATERIALS AND METHODS: Using a modified double sandwich enzyme-linked immunosorbent assay, we measured serum KGF in 56 men with prostate cancer and 81 men with BPH. Comparative analyses were made with total serum prostate specific antigen (PSA), disease stage and clinical grade. RESULTS: Following optimization, a sensitive and reproducible assay for serum KGF measurement was developed. Serum KGF levels tend to be higher in men with BPH compared to those with prostate cancer (1,242 and 828 pg./ml., respectively). A weak but significant linear relationship between PSA and KGF (p = 0.034) was found in patients with BPH. There was no association between KGF and tumor grade or stage but there was a strong positive linear relationship between PSA and KGF (p = 0.006, R(2) = 68.3%) in low grade tumors. In those men with serum PSA less than 10 ng./ml. KGF levels were significantly higher in BPH compared to prostate cancer cases (965 +/- 245 and 133 +/- 61.3 pg./ml., respectively, p = 0.0058). Using a KGF threshold range of 500 to 900 pg./ml., specificity for detecting BPH was 88% to 100% and the positive predictive value was 92% to 100%. CONCLUSIONS: We have optimized a reproducible and sensitive enzyme-linked immunosorbent assay system for the measurement of serum KGF. Overall KGF levels tend to be lower in patients with prostate cancer than with BPH. In patients with serum PSA less than 10 ng./ml. serum KGF levels were significantly higher in the BPH compared to the prostate cancer group. A large prospective study is indicated to assess the role of serum KGF measurement in patients with prostate cancer.