C-reactive protein and erythrocyte sedimentation rate in differential diagnosis between infections and neoplastic fever in patients with solid tumours and lymphomas.

The goals of our work were to study prospectively the possibility of differentiating between infections and neoplastic fever in adult cancer patients on admission, by means of C-reactive protein (CRP) and erythrocyte sedimentation rate (ESR) or of follow-up CRP values. Patients and methods were as follows: the final infection group consisted of 56 patients and the noninfection group of 10 patients with neoplastic fever; CRP was measured on days 0, 3 and 5 and ESR at entry. The main results showed that the median CRP did not differ between the groups (91 mg/l vs 102 mg/l) on entry, while the ESR level was higher in the neoplastic fever group (50 mm/H vs 89 mm/H, P = 0.023). On admission, both markers had low area under receiver operating characteristic curves for the demonstration of infection (CRP 0.42; ESR 0.27). The CRP level dropped significantly in the infection group within 5 days (P = 0.009). We conclude that neither of the markers was useful in differentiating between infections and neoplastic fever on admission, but that the follow-up CRP values were advantageous in this respect.