Prevalence of functional iron deficiency in patients with malignancies and its impact on fatigue-specific quality of life.

Background: Functional iron deficiency (FID) as defined by the European Society for Medical Oncology (ESMO) occurs in patients with malignant neoplasms and might be a target to improve fatigue-specific quality of life (QoL). The prevalence of FID in that population, especially in patients with a haemoglobin (Hb) of 10-11 g/dl and Hb > 11 g/dl, is unclear. The aim of this study was to obtain data on the prevalence of FID in patients with solid tumours and haematological malignancies independent of Hb and age, and to investigate the potential of FID as a target to improve fatigue-specific QoL. Patients and methods: This was a prospective, observational single-centre study assessing adult patients with malignancies 4 weeks before disease-directed therapy. Patients without known iron deficiency (ID), iron supplementation, therapy with erythropoiesis-stimulating agents, or red blood cell transfusions 8 weeks before inclusion were eligible. Fatigue-specific QoL data were assessed by the Functional Assessment of Chronic Illness Therapy-Fatigue (FACIT-F) questionnaire. Results: FID was found in 30% of 146 assessed patients, of which 77% had a Hb > 11 g/dl. FID was documented in 63% of patients with a Hb of 10-11 g/dl and in 26% of patients with Hb > 11 g/dl. The total scores for FACIT-F were not significantly different between patients with FID, absolute ID, and no ID. Conclusion: FID is highly prevalent also in patients with a Hb of 10-11 g/dl and Hb > 11 g/dl and should be distinguished from absolute ID. Fatigue-specific QoL was not influenced by iron status, and improvement of QoL by treating FID without anaemia in patients with malignancies is therefore unlikely.