Ferric Carboxymaltose Versus Iron Sucrose for Iron Deficiency Anemia After Radical Gastrectomy for Gastric Cancer

• Ferric Carboxymaltose (FCM) (Drug): Single-dose intravenous infusion administered on postoperative day 1.
• Iron Sucrose. (Drug): Repeated intravenous infusions to reach equivalent total iron dose.

Primary outcomes

• Hemoglobin response rate at 3 weeks post-treatment [3 weeks after treatment initiation]: Proportion of patients with hemoglobin increase ≥15g/L or absolute hemoglobin ≥110g/L at 3 weeks after study drug administration
• Proportion of participants meeting hemoglobin response criteria at postoperative Week 3 [Postoperative Week 3]: Hemoglobin response is defined as hemoglobin increased by ≥15 g/L from baseline (pre-medication on postoperative Day 1), OR absolute hemoglobin level ≥110 g/L at Week 3. Participants receiving allogeneic red blood cell transfusion will be excluded from response statistical analysis. Baseline hemoglobin value is collected before study drug administration on postoperative Day 1.

Secondary outcomes

• Mean change in hemoglobin and hemoglobin normalization rate at postoperative Week 3 and Week 8 [Postoperative Week 3, Postoperative Week 8]: Mean ΔHb (hemoglobin difference vs baseline) at Week 3 and Week 8; Hb normalization standard: male ≥120 g/L, female ≥110 g/L.
• Changes in iron metabolism indicators and serum phosphorus at Week 3 and Week 8 [Postoperative Week 3, Postoperative Week 8]: Changes from baseline in serum ferritin, transferrin saturation and serum phosphorus at postoperative Week 3 and Week 8.
• Allogeneic blood transfusion demand within 8 weeks after radical gastrectomy [Baseline to postoperative Week 8]: Transfusion proportion, average units of transfused red blood cells and total transfusion frequency of each participant from baseline to postoperative Week 8.

Sex: All, ages: 18 Years to 75 Years

Inclusion Criteria:

* Age 18 to 75 years, sex male or female, and body weight ≥ 50 kg.
* Histopathologically confirmed gastric cancer (TNM stage I-III according to the AJCC 8th edition) and have undergone curative (R0) resection.
* Postoperative anemia defined as a hemoglobin (Hb) level < 100 g/L within 24 hours after surgery (i.e., on postoperative day 1), meeting the diagnostic criteria for postoperative anemia in gastric cancer patients.
* Evidence of iron deficiency, as indicated by:
* serum ferritin < 30 μg/L, or
* serum ferritin < 100 μg/L and transferrin saturation (TSAT) < 20%, confirming iron-deficiency anemia.
* Eastern Cooperative Oncology Group (ECOG) performance status score of 0-2.
* Adequate hepatic, renal, and coagulation function, defined as:
* ALT and AST ≤ 2.5 × upper limit of normal (ULN),
* serum creatinine ≤ 1.5 × ULN,
* prothrombin time international normalized ratio (INR) ≤ 1.5.
* Estimated life expectancy ≥ 3 months.
* Voluntary written informed consent and ability to comply with the trial treatment and follow-up procedures.

Exclusion Criteria:

Non-iron-deficiency anemia (e.g., hemolytic anemia, thalassemia, megaloblastic anemia, aplastic anemia, tumor-related non-iron-deficiency anemia, etc.) or disorders of hemoglobin synthesis.

* Known hypersensitivity to ferric carboxymaltose, iron sucrose injection, or any of their excipients.
* Evidence of iron overload (serum ferritin > 1000 μg/L) or a history of hemochromatosis.
* Severe hepatic or renal impairment, defined as:
* ALT/AST > 2.5 × upper limit of normal (ULN),
* serum creatinine > 1.5 × ULN,
* or coagulopathy (INR > 1.5);
* or active bleeding (e.g., major postoperative anastomotic hemorrhage, intra-abdominal bleeding, etc.).
* Receipt of oral iron, intravenous iron, or erythropoiesis-stimulating agents (ESAs) / erythropoietin (EPO) within the past 3 months prior to screening.
* Concurrent other malignancies, severe cardiovascular disease (e.g., heart failure, history of myocardial infarction, severe arrhythmias), uncontrolled infectious disease (e.g., sepsis), or immunodeficiency disorders.
* Pregnant or breastfeeding women, or women who plan to become pregnant during the trial period.
* Inability to comply with the treatment and follow-up procedures (e.g., due to cognitive impairment, psychiatric disorders), or any other condition that, in the investigator's judgment, would render the participant unsuitable for inclusion in the study.

• zhaojian Niu, MD, PhD, Principal investigator, The Affiliated Hospital of Qingdao University