At present, few studies have examined the effect of iron therapy in iron deficient cancer patients without anaemia. However, studies in iron deficient patients with anaemia show that iron therapy can may be effective against both absolute and functional iron deficiency anaemia in association with a wide range of tumour types1. Intravenous iron therapy has been shown to translate into significant clinical benefits such as reducing the need for alternative therapies, reducing the need for blood transfusions in patients with gynaecological malignancies undergoing chemotherapy, and reducing the need for erythropoietin-stimulating agent (ESA) treatment, all of which may be associated with significant risks of morbidity or mortality1-4.
Effect of iron therapy on haemoglobin levels in patients with iron deficiency anaemia
Haemoglobin and haematocrit levels have also been shown to exhibit a greater increase following treatment with intravenous iron when compared with no iron therapy (see figure below), with an additional reduction in the need for blood transfusions observed in this group3,4.
Figure 3. Significant increases in haemoglobin with iron therapy in patients with cancer undergoing chemotherapy3
Copyright permission obtained from Dangsuwan et al, 2010.
Furthermore, a randomised controlled study has shown that correcting iron deficiency with intravenous iron therapy is as effective in achieving a haemoglobin response (haemoglobin increase >1 g/dL) for patients with absolute iron deficiency anaemia as ESA therapy for patients with non-iron deficient anaemia5.
Several clinical studies have demonstrated that correction of iron deficiency provides significant benefits in patients with cancer undergoing ESA therapy for iron deficiency anaemia. A meta-analysis of seven studies demonstrated that intravenous iron treatment resulted in a 28% increase in the rate of haemoglobin response (haemoglobin levels >12 g/dL or an increase >2 g/dL) compared with no iron therapy5. Intravenous iron therapy was also associated with a 24% reduction in the rate of blood transfusions both with ESA (RR 0.76 [95% CI 0.6–0.95]; p=0.02, overall effect), and without ESA (relative risk [RR] 0.52 [95% CI 0.34–0.80]; p=0.002, overall effect), and an increase in the number of patients achieving improvements in quality of life5. Iron therapy may also enable a reduction in the ESA dose in patients with iron deficiency anaemia and cancer6.
Oral iron versus intravenous iron therapy
Several clinical guidelines recognise the greater efficacy of intravenous versus oral iron therapy for iron deficiency anaemia7. A study comparing oral and intravenous iron therapy in patients with cancer receiving ESA therapy for anaemia demonstrate that both intravenous and oral iron increase the rate of haemoglobin response (haemoglobin levels >12 g/dL or an increase >2 g/dL) but that the extent of the increase is significantly greater with intravenous versus oral iron treatment (see figure below)8. Improvements in quality of life with intravenous iron were also markedly greater than with oral iron.
Figure 4. Haemoglobin responses (top) and quality of life outcomes (bottom) with iron therapy in patients with cancer and iron deficiency anaemia8
Copyright permission obtained from Auerbach et al, 2004.
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