Anemia is defined as a decrease in the red blood cell mass circulating in the bloodstream, and derives from an imbalance in the production and loss of erythrocytes. Symptoms and signs associated with anemia result from impaired oxygen delivery to the tissues. Common symptoms include fatigue, malaise, weakness, dyspnea on exertion, palpitations, and chest pressure. Patients may manifest additional overt signs such as pallor, tachycardia, impaired mentation, high-output congestive heart failure, shock, and death. The 1968 World Health Organization (WHO) criteria define anemia as hemoglobin less than 12 g/dl in women and hemoglobin less than 13 g/dl in men. The current working definition of anemia is a hemoglobin level that is two standard deviations below the mean hemoglobin level for a given sex and age.
Among patients with cancer, anemia is a prevalent complication of both the disease and its treatment. Nearly 50% of patients have laboratory evidence of anemia at the time of diagnosis with cancer, although it may be initially quite subtle and insidious in onset. With hematologic malignancies, anemia is coincident in as many as 70% of patients. Cancer patients with a particularly increased risk for anemia are those with a low hemoglobin before the diagnosis of cancer, those with lung or gynecologic cancers, and those receiving platinum-based therapy, and female sex (1). Due to the prevalence of anemia with cytotoxic chemotherapy, grading systems have been established to standardize reporting of myelosuppression in clinical studies and to guide clinical decision-making. The grading system offered by the National Cancer Institute is presented in Table 18-1 (2).
TABLE 18-1NCI GRADING SYSTEM FOR ANEMIA ||Download (.pdf) TABLE 18-1 NCI GRADING SYSTEM FOR ANEMIA
|Grade ||Severity ||Hemoglobin (g/dl) |
|0 ||Normal ||12.0–16.0 (women) |
| || ||14.0–18.0 (men) |
|1 ||Mild ||10.0–lower limit of normal |
|2 ||Moderate ||8.0–<10.0 |
|3 ||Severe ||6.5–<8 |
|4 ||Life threatening ||Life threatening |
|5 ||Death ||Death |
Anemia has been shown to decrease quality of life in cancer patients (3). The correlation between fatigue and hemoglobin level is particularly strong, establishing fatigue as a modifiable risk factor for clinical trials of transfusion or erythropoietins (EPOs). A negative impact of anemia on cancer patient prognosis and survival has been reported in both solid and hematologic malignancies (4). Because anemia in the cancer patient is frequently multifactorial, the appropriate diagnostic evaluation and therapeutic interventions must be individualized to fit the cause, the severity of anemia, and the clinical setting. The mainstay of treatment is treating the underlying cause or supportive care with packed red blood cell transfusions and EPO with or without iron supplementation.
Hematopoiesis and the size of each compartment within its developmental hierarchy, including red blood cell production, are tightly controlled by a dynamic balance of hematopoietic stem cell (HSC) self-renewal and differentiation through subsequent compartments to mature effector ...