Patients with active cancer had significantly higher serum levels of fibrinogen (mean ± SD: 4.44 ± 1.82 g/L vs. 3.56 ± 1.02 g/L; t = 3.49, P < 0.01), D-dimer (median [IQR]: 2.23 mg/mL [0.98–10.76] vs. 0.35 mg/mL [0.27–0.48]; Z = −9.55, P < 0.01), and CRP (median [IQR]: 18.40 mg/L [5.45–46.00] vs. 3.90 mg/L [2.80–6.33]; Z = −7.35, P < 0.01) but significantly lower levels of hemoglobin (mean ± SD: 119.79 ± 25.68 g/L vs. 143.61 ± 18.57 g/L; t = −6.63, P < 0.01) than those without. Here, CRP is linked to cancer.