The correlation between high sensitive C-reactive protein and bone metastasis of patients with newly diagnosed prostate cancer

Abstract

Objective To assess the correlation between high sensitive C-reactive protein and bone metastasis of patients with newly diagnosed prostate cancer. Methods From Jan. 2010 to Dec. 2015, a total of 294 consecutive patients with newly diagnosed prostate cancer by prostate biopsy were enrolled in this study. The median age was 70(65-75) years. There were 90(30.6%) patients with a positive DRE (digital rectal examination). The median prostate volume, PSA and PSAD were 36.5 ml(25.2-53.1 ml), 32.95 ng/ml(14.49-82.89 ng/ml) and 0.90 ng/(ml·cm3)[0.44-1.95 ng/(ml·cm3)], respectively. There were 37(12.6%) patients with a Gleason score ≤ 6, 97(33.0%) with a Gleason score of 7 and 160(54.4%) with a Gleason score ≥ 8. Clinical stage was also evaluated, including 94(32.0%) diagnosed as T1 stage, 132(44.9%) T2 stage, 50(17.0%) T3 stage, and 18(6.1%) T4 stage. Regional lymph node metastases were found in 29(9.9%) patients. All patients underwent bone scan and 59 patients showed bone metastases. One patient showed pulmonary metastases by computed tomography (CT). The difference of hs-CRP level between patients with bone metastasis and without bone metastasis was analyzed by Mann-Whitney U test. The difference of bone metastasis rate between the patients with elevated hs-CRP level (hs-CRP>3.0 mg/L) and normal hs-CRP (hs-CRP≤3.0 mg/L) level was analyzed by Chi-squared test. Logistic regression was used to evaluate the effect of hs-CRP, prostate specific antigen (PSA), prostate specific antigen density (PSAD), Gleason score and clinical stage on bone metastasis. Areas under operating characteristic curves (AUC) were used to compare the predictive value of hs-CRP, PSA and PSAD. Results The hs-CRP level of the 294 patients ranged from 0.77 mg/L to 6.33 mg/L, with a median of 1.80 mg/L. The median ( interquartile range ) of hs-CRP was 6.90 mg/L (1.95-13.74 mg/L) in patients with bone metastasis which is higher than 1.43 mg/L (0.70-4.32 mg/L) in those without bone metastasis (P<0.05). The level of PSA, Gleason score and clinical stage were also significantly different between the two groups (P<0.05). The rate of bone metastasis in patients with elevated hs-CRP was 37.2%(42/113), higher than that of patients with normal hs-CRP(P<0.001). According to the logistic regression analysis, hs-CRP(OR=1.149, 95%CI 1.080-1.222, P<0.05), PSA(OR=1.013, 95%CI 1.002-1.023, P<0.05)and Gleason score(OR=2.515, 95%CI 1.198-5.279, P<0.05) were significant independent predictors for bone metastasis. AUC of hs-CRP was 0.720 and the cutoff value was 3.1 mg/L. Conclusions High hs-CRP is significantly correlated with bone metastasis. Measurement of hs-CRP plays an important role in predicting bone metastasis among patients with newly diagnosed prostate cancer. Key words: High sensitive C-reactive protein; Prostate Cancer; Bone metastasis