Background: Patients with an elevated erythrocyte sedimentation rate (ESR) are often suspected of having malignant disease and are subjected to extensive investigations. Thus, the finding of an elevated ESR can result in considerable costs and might even be dangerous for the patient if invasive studies are ordered.
Objectives: Our aims were to establish (i) the prevalence of malignant diseases in hospitalized patients and out-patients with elevated ESR; and (ii) the long-term incidence of malignant diseases in patients during 5 years after unsuccessful investigation for elevated ESR.
Methods: A cross-sectional survey was carried out in 128 patients admitted to the Department of General Internal Medicine, University of Kiel and in 94 out-patients under the care of a GP. A retrospective cohort study of 50 patients was also carried out by contacting GPs of patients discharged from hospital after unsuccessful investigation.
Results: In the hospitalized patients, the ESR was elevated in 53.1% (68/128) and was normal in 46.9% (60/128). Malignancy was found in 25.0% (17/68) of patients with elevated ESR and in 15% (9/60) of patients with normal ESR (P = 0.16). Of the out-patients, 94 patients with elevated ESR were investigated, of whom 8.5% (8/94) had malignancies (P = 0.004 compared with hospitalized patients). In the follow-up study of 50 patients who had been discharged with the diagnosis "elevated ESR of unknown origin", follow-up information was available from 38 individuals. Of these, 71.0% (27/38) had not developed signs or symptoms of any disease at the time of investigation. Malignant disease had developed in only 5.3% (2/38).
Conclusion: The prevalence of malignancy in patients with elevated ESR is low, in both the clinical and the general practice setting. Elevation of ESR is not an early sign of malignant disease and does not justify extensive investigation in a patient who has no symptoms which are suggestive of a tumour.