Intravenous Iron Injection in Cancer Patients With Anemia

* Multifactorial pathogenesis is involved in anemia of cancer patients and defining the causes of anemia is not always simple. * Currently, treatment options available for anemia in cancer patients include red blood cell (RBC) transfusion, erythropoietin stimulating agent (ESA), and iron supplementation, accompanying considerable pros and cons for each treatment. * Previous studies have demonstrated benefit when treating with IV iron in combination with ESA and, more recently, evidence is emerging to suggest a role for IV iron alone. * In this study, investigator will assess the efficacy of intravenous iron for the treatment of anemia in cancer patients. * Improvement of anemia and the improvement of quality of life compared to conservative treatment of intravenous iron