Diagnosis and management of tumor-related anemia Cancer related anemia (CRA) refers to anemia that occurs during the development of the disease and during the treatment of tumor patients, and is one of the common concomitant diseases of malignant tumors. Factors that cause CRA include: tumor itself: tumor depletion, blood loss, hemolysis, bone marrow invasion. Tumor treatment: bone marrow suppression due to radiotherapy. From a pathophysiological point of view, tumor-associated anemia can be caused by decreased erythropoiesis, excessive erythrocyte destruction, blood loss or a combination of these factors, as well as other complex causes such as poor diet and insufficient iron intake (common in tumor patients). Inadequate erythropoiesis may be caused by defects in EPO cell production, impaired hemoglobin synthesis, bone marrow suppression, or renal failure. Erythrocyte destruction arises from many factors, including intrinsic factors (e.g., enzyme defects) or tumor chemotherapeutic agents (e.g., antimetabolites), malignancy itself stimulating autoimmune hemolysis (e.g., chronic lymphocytic leukemia), or inflammatory cytokines produced by the tumor (e.g., tumor necrosis factor). Blood loss may be due to acute bleeding or tumor-associated coagulation disorders (e.g., diffuse intravascular coagulation). In oncology patients, multiple factors such as iron deficiency, vitamin B12 or decreased folate production can lead to decreased peripheral erythropoiesis. CAR can be classified according to red blood cell morphology: anemia severity grading NCI, WHO and domestic grading vary. Treatment of CRA 1. Blood transfusion therapy In principle, blood transfusion therapy should not be considered until the hemoglobin level of patients with tumor-associated anemia significantly decreases to 79/dL or 89/dL. And when Hb<79/dL or when there is an urgent clinical need to correct hypoxia, or when chronic symptomatic anemia that does not respond to EPO therapy and severe anemia that does not have time and opportunity to receive EPO therapy can be considered for transfusion therapy. 2 .EPO treatment 3 .CRA treatment expert consensus