RESUMEN
AIM: To identify the incidence and etiology of anemia after gastrectomy in patients with long-term follow-up after gastrectomy for early gastric cancer. METHODS: The medical records of those patients with early gastric adenocarcinoma who underwent curative gastrectomy between January 2006 and October 2007 were reviewed. Patients with anemia in the preoperative workup, cancer recurrence, undergoing systemic chemotherapy, with other medical conditions that can cause anemia, or treated during follow up with red cell transfusions or supplements for anemia were excluded. Anemia was defined by World Health Organization criteria (Hb < 12 g/dL in women and < 13 g/dL in men). Iron deficiency was defined as serum ferritin < 20 µg/dL. Vitamin B12 deficiency was defined as serum vitamin B12 < 200 pg/mL. Iron deficiency anemia was defined as anemia with concomitant iron deficiency. Anemia from vitamin B12 deficiency was defined as megaloblastic anemia (mean cell volume > 100 fL) with vitamin B12 deficiency. The profile of anemia over 48 mo of follow-up was analyzed. RESULTS: One hundred sixty-one patients with gastrectomy for early gastric cancer were analyzed. The incidence of anemia was 24.5% at 3 mo after surgery and increased up to 37.1% at 48 mo after surgery. The incidence of iron deficiency anemia increased during the follow up and became the major cause of anemia at 48 mo after surgery. Anemia of chronic disease and megaloblastic anemia were uncommon. The incidence of anemia in female patients was significantly higher than in male patients at 12 (40.0% vs 22.0%, P = 0.033), 24 (45.0% vs 25.0%, P = 0.023), 36 (55.0% vs 28.0%, P = 0.004), and 48 mo (52.0% vs 31.0%, P = 0.022) after surgery. Patients with total gastrectomy showed significantly higher incidence of anemia than patients with subtotal gastrectomy at 48 mo after surgery (60.7% vs 31.3%, P = 0.008). The incidence of iron deficiency was significantly higher in female patients than in male patients at 6 (35.4% vs 13.3%, P = 0.002), 12 (45.8% vs 16.8%, P < 0.001), 18 (52.1% vs 22.3%, P < 0.001), 24 (60.4% vs 20.9%, P < 0.001), 36 (62.5% vs 29.2%, P < 0.001), and 48 mo (66.7% vs 34.7%, P = 0.001) after surgery. CONCLUSION: Anemia was frequent after gastrectomy for early gastric cancer, with iron deficiency being the major cause. Evaluation for anemia including iron status should be performed after gastrectomy and appropriate iron replacement should be considered.