This study is designed to evaluate the efficacy of Ferinject® in improving acute isovolemic anemia after gastrectomy for gastric cancer in terms of Quality of life(QOL )and objective measures (Hb and iron parameters).

Furthermore, the tolerability and safety of Ferinject® treatment will be evaluated.

Randomized patient-blind placebo controlled study. Hb level of 10 g/dl will be used as a cut-off value for our study based on the guidelines published by American Society of Clinical Oncology and the American Society of Hematology for the treatment of cancer-related anemia, recommending Hb<10 g/dl as a treatment threshold.

Ferinject® to be administered based on Hb and body weight per approved summary of product characteristics (SmPC).

5 - 7 days after gastrectomy for gastric cancer, consented patients with 7g/dl≤Hb<10g/dl will be administered Ferinject® or placebo (normal saline) based on the results of randomization.

• Study Group Ferinject®to be administered as IV drip infusion or undiluted bolus injection with a minimum administration time of 15minutes (for 1000mg single administration) for body weight ≥50 Kg or 6 minutes (for 500mg single administration) for body weight <50Kg .

Note, Ferinject® should be administered to a maximum of 20mg iron/kg. Therefore in patients with a body weight <50kg, administration of Ferinject® should be limited to 500mg at baseline . All patients with a serum ferritin value <15ng/mL at week 4 visit that a second dose (of 500mg iron or equivalent placebo) will be given.(Study group: Ferinject®500mg, Control Group:Placebo)

• Control Group Placebo will be in the form of normal saline administered over same time period as equivalent Ferinject® administration. IV drip infusion or undiluted bolus injection with a minimum administration time of 15 minutes (200mL as infusion or 20mL as bolus injection) for body weight ≥50 Kg or 6 minutes (100mL normal as infusion or 10mL as bolus injection) for body weight <50 Kg.

Inclusion Criteria:

• ≥ 20 years old
• 7g/dl ≤ Hb < 10g/dl at 5 - 7 days after gastrectomy for gastric cancer
• signed written informed consent

Exclusion Criteria:

• a concurrent medical condition(s) that would prevent compliance or participation or jeopardize the health of the patient
• hypersensitivity to any component of the formulation
• active severe infection/inflammation
• History of transfusion, erythropoietin, > 500 mg intravenous iron administration within 4 weeks prior to screening.
• History of acquired iron overload.
• Pregnancy or lactation.
• Decreased renal function (defined as creatinine clearance < 50 mL/min calculated by Cockcroft-Gault)
• Chronic liver disease or increase of liver enzymes (ALT, AST) > 3 times the upper limit of normal range.
• Participation in any other interventional study within 1 month prior to screening.