C-reactive protein is significantly associated with prostate-specific antigen and metastatic disease in prostate cancer

To further analyse the relationship of c-reactive protein (CRP) levels to prostate cancer, by measuring CRP in men with prostate cancer and benign prostatic hypertrophy (BPH), as chronic inflammation has long been linked to cancers with an infectious cause and CRP is a nonspecific marker for inflammation, associated with prostate cancer incidence and progression. Data from 114 men, most of whom had had radioactive seeds implanted, were evaluated from November 1990 to April 2002. In addition, 27 men were included who had biopsy-confirmed BPH. CRP was assessed with an automated chemiluminometric high-sensitivity assay kit. There was no significant difference in CRP levels in men with localized prostate cancer or BPH but levels were significantly higher in men with bone metastases. There was also a significant correlation of CRP level with prostate-specific antigen (PSA) in those with cancer. Because PSA is correlated with disease stage, multiple linear regression was used with CRP as the dependent variable, and PSA and disease stage as independent variables. The regression was significant overall (P < 0.001) and the effect of disease stage on CRP (P < 0.001) was independent of the effect of PSA level (P = 0.001). The strong association of CRP with PSA, independent of tumour stage, suggests that inflammation might be fundamental in prostate cancer, and that chronic inflammation may be a legitimate target for prostate cancer chemoprevention and treatment.