Haemoglobin and fatigue in cancer patients: inseparable twins?

Tiredness is one of the most common symptoms in patients with cancer, and, because of its multifaceted manifestation in this population today, it is g enerally termed the "fatigue syndrome". Causal relationships are complex an d multidimensional. Research suggests that the type and stage of cancer pla y an important role, and that side effects of cancer treatment as well as p sychological factors may be involved. A causal relationship between fatigue and a certain degree of anaemia has been suggested. Whilst it is acknowled ged that severe anaemia causes "fatigue", the influence of mild, chronic an aemia on quality of life is not yet clear. It is the aim of this prospectiv e, descriptive study to investigate the correlation between "fatigue" in ca ncer patients and their haemoglobin levels. Haemoglobin was measured in 444 cancer patients with different types and stages of cancer and treatment mo dalities. Concurrently, fatigue was assessed with the new Fatigue Assessmen t Questionnaire (FAQ). In addition, the Karnofsky Index was assessed and de pression and anxiety were measured with the Hospital Anxiety and Depression Scale. Results: Cancer patients with a haemoglobin level below 11 g/dl suffered fr om fatigue more than patients with higher haemoglobin levels (r = -0.196, p <0.001). The correlation of "fatigue" was most prominent with physical fat igue such as reduced physical performance or weakness. The Karnofsky Index correlated significantly with the haemoglobin concentration. Patients with lower haemoglobin levels showed more signs of depression than those with hi gher levels. Conclusions: The grade of anaemia correlates with intensity of fatigue in c ancer patients and also with depression. Both can be related to the advance d disease situation. Data suggest that if levels of haemoglobin are lower t han 11 g/dl, subjective fatigue should be specifically assessed to plan tre atment according to the patients' need. It remains to be substantiated when and which treatment is indicated to alleviate fatigue and to support quali ty of life in the individual anaemic cancer patient.