Abstract

Oral iron promotes intestinal tumourigenesis in animal models. In humans, expression of iron transport proteins are altered in colorectal cancer. This study examined whether the route of iron therapy alters iron transport and tumour growth. Colorectal adenocarcinoma patients with pre-operative iron deficiency anaemia received oral ferrous sulphate (n = 15), or intravenous ferric carboxymaltose (n = 15). Paired (normal and tumour tissues) samples were compared for expression of iron loading, iron transporters, proliferation, apoptosis and Wnt signalling using immunohistochemistry and RT-PCR. Iron loading was increased in tumour and distributed to the stroma in intravenous treatment and to the epithelium in oral treatment. Protein and mRNA expression of proliferation and iron transporters were increased in tumours compared to normal tissues but there were no significant differences between the treatment groups. However, intravenous iron treatment reduced ferritin mRNA levels in tumours and replenished body iron stores. Iron distribution to non-epithelial cells in intravenous iron suggests that iron is less bioavailable to tumour cells. Therefore, intravenous iron may be a better option in the treatment of colorectal cancer patients with iron deficiency anaemia due to its efficiency in replenishing iron levels while its effect on proliferation and iron metabolism is similar to that of oral iron treatment.

Abstract

BACKGROUND Anemia is common with esophagogastric adenocarcinoma, increasing mortality, blood transfusions, and reducing quality of life (QOL). No clear evidence exists for safe and effective treatment. METHODS Anemic patients (Hb <12 g/dl women, <13 g/dl men) with esophagogastric adenocarcinoma were recruited before initiation of palliative chemotherapy. Patients were randomized to standard care or single dose of intravenous iron isomaltoside (IVI) before chemotherapy. Post-chemotherapy changes in hemoglobin (Hb), ferritin, transferrin saturations (TSAT), blood transfusions, and QOL were recorded for three cycles of chemotherapy. RESULTS Twenty-seven patients were randomized to standard care (n = 13) or IVI (n = 14). No significant change in Hb was seen (standard care MD -0.6 g/dl 95% CI -0.1-1.1 g/dl, P = 0.336; IVI MD +0.5 g/dl 95% CI -0.1-1.1 g/dl, P = 0.903). An increase in ferritin was seen with IVI after cycle one of chemotherapy (standard care 116 ng/ml; IVI 770 ng/ml, P < 0.05). No difference in blood transfusions was seen between groups (P = 0.851). IVI improved QOL with physical well-being, emotional well-being, anemia-specific QOL, trial outcome index, and total scores all exceeding minimum clinically important difference. No improvement was seen with standard care. CONCLUSIONS This feasibility study suggests IVI improves quality of life and ferritin. Larger adequately powered studies are required to definitively conclude if hemoglobin and blood transfusion changes with IVI.