Anemia is a condition in which the number of circulating red blood cells is lower than normal causing a decrease in oxygen delivery to tissues in the body. The Mayo Clinic reports that a normal hematocrit, which is the percentage of red blood cells in the blood, ranges between 32 and 43 percent in adults. A review in the September 2009 issue of "The Oncologist" reports the prevalence of anemia in patients with solid tumors is near 40 percent and is approximately doubled in patients with blood cancers. This source also notes that the incidence of anemia increases with the duration of chemotherapy. Iron deficiency exacerbates anemia because iron is incorporated into the oxygen carrying protein, hemoglobin in red blood cells.
Combination Therapy
Cancer-related anemia is normally treated with the drugs epoetin and darbepoetin that stimulate red blood cell production in the bone marrow. However, a review in the March 2009 issue of the journal "Cancer" notes between 30 and 50 percent of patients is unresponsive to these drugs. The lack of response is related to iron deficiency because if iron is unavailable hemoglobin cannot be made and therefore drugs that stimulate red blood cell production are ineffective.
Intravenous Iron Supplements
The review in the journal "Cancer" reports that two large studies conducted in the United States found that intravenous administration of iron in conjunction with epoetin significantly improved blood profiles in people with cancer-related anemia. Another study in the April 2008 issue of the "Journal of Clinical Oncology" reports that an intravenous dose of 200 mcg of iron in combination with darbepoetin and chemotherapy that took place every three weeks improved blood profiles and reduced the number of required blood transfusions.
Oral Iron Supplements
An article in the July 2006 issue of "Oncology" reports that administering iron supplements orally to cancer patients to treat anemia is not recommended because of poor intestinal absorption and the high likelihood of gastrointestinal side effects. Additionally, the review in "Cancer" says that studies that have evaluated the efficacy of oral iron supplementation in conjunction with drugs for stimulating red blood cell production for treating cancer-related anemia demonstrate it is no more effective than placebo.
References
- "The Oncologist"; Anemia Management in Oncology and Hematology
- "Cancer"; Iron Supplementation and Erythropoiesis-Stimulatory Agents in the Treatment of Cancer Anemia; Paolo Pedrazzoli et al.; March 2009
- PubMed: The Role of Intravenous Iron in Cancer-Related Anemia
- PubMed: Randomized, Multicenter, Controlled Trial Comparing the Efficacy and Safety of Darbepoetin Alpha Administered Every 3 Weeks with or without Intravenous Iron in Patients with Chemotherapy-Induced Anemia
- MayoClinic: Anemia: Tests and Diagnosis
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