Intravenous Iron Supplementation Alone for Treatment of Anemia in Cancer Patients

Introduction: Anemia is a common issue in cancer patients and multifactorial pathogenesis is involved. Defining the cause of anemia is not easy, and patients usually left untreated with sub-optimal diagnoses of cause. Recently, evidence is emerging to suggest a role for intravenous (IV) iron alone in anemia with cancer patients. Herein, we evaluated the efficacy of IV iron for improvement of anemia in cancer patients.

Methods: Eligible patients were as followed; 1) adult patients aged 18 or more who were diagnosed with solid cancer or lymphoma, 2) who were treated with anticancer therapy within 2 months of enrollment, 3) whose hemoglobin (Hb) level of 8.0-10.5g/dL or who experienced a drop of Hb by 2 g/dL or more from baseline. Patients who meet the following criteria were excluded; 1) who received iron replacement or erythropoietin stimulating agent within 4 weeks or enrollment, 2) who has ongoing bleeding, 3) whose disease with bone marrow involvement , 4) ferritin > 800ng/ml and TSAT (transferrin saturation) ≥ 50%. At first visit after enrollment (visit 0), ferinject® (ferric carboxymaltose) 1000mg was administered intravenously. Thereafter, hemoglobin (Hb) response defined by increase of Hb ≥ 1.0g/dL or Hb correction ≥ 11.0g/dL (only if baseline Hb was 8.0-10.5g/dL) was assessed at visit 1, visit 2 and visit 3. The interval between each visit should be at least 2 weeks apart, but should not be exceeded 4 weeks.

Results: Between Oct 2010 and Jan 2017, a total of 100 patients were enrolled. Of these 100 patients, 89 patients who had followed at least once were analyzed in this study. The median age was 59 years (range, 24-82). Lung cancer was the most common (n=25, 28.1%) followed by breast cancer (n=23, 25.8%), gastrointestinal cancer (n=18, 20.2%), lymphoma (n=15, 16.9%) and other types of solid cancer (n=8, 9.0%). Almost patients received cytotoxic chemotherapy alone (n=49, 55.1%), and the rest received concurrent chemo-radiotherapy (n=4, 4.5%), target agent (n=4, 4.5%) and target agent plus radiotherapy (n=1, 1.1%). Of 89 patients, 61 patients completed 3 times of follow-up (68.5%) after IV iron treatment, whereas 21 (23.6%) and 7 patients (7.9%) completed 1 and 2 times of follow-up only. Overall, Hb response after administration of ferinject® was noticed in 57 out of 89 patients enrolled (64.0%). Regarding the timing of Hb response by follow up visit, 33, 18 and 6 patients showed Hb response at visit 1 (57.9%), visit 2 (31.6%) and visit 3 (10.5%), respectively. When excluding 16 patients (18.0%) with absolute iron deficiency anemia (IDA) defined by ferritin <30ng/mL or TSAT <20%, Hb response rate in remaining 73 patients was 57.5%. Of these 73 patients, there were 53 patients with functional IDA defined by ferritin 30-500ng/mL and TSAT <50%. No significant difference was observed in Hb response rate between patients with and without functional IDA (62.3% vs 45.0.%, p=0.183). There were 10 patients enrolled whose ferritin > 800ng/mL or TSAT ≥ 50%, in which 5 of 10 patients showed Hb response (50.0%).

Conclusion: IV iron supplementation alone showed promising result in improving anemia in cancer patients. This is only a preliminary report and analysis of biochemical parameters for selecting patients who may benefit from IV iron treatment is in progress.