Definition, classification and characterization of anemia in cancer

Anemia is defined as a condition of decreased red blood cell (RBC) mass, reflected in a decreased hemoglobin (Hb) and hematocrit (Hct) level. Signs traditionally used in the physical diagnosis of anemia are pallor of the conjunctivae, nail beds, face, palms, and palmar creases. Among these, only pallor of the conjunctivae, nail beds, and palms can be used in patients of any race. There is evidence suggesting that conjunctival pallor may be more sensitive than pallor of the nail beds and the palm, but conjunctival pallor as such is more frequently evident in association with Hb levels <9g/dl and may be absent even in the presence of such a degree of anemia (Nardone et al. 1990; Sheth et al. 1997; Strobach et al. 1988). Conjunctival pallor, however, should always be a reason to determine Hb level. Hb level should also be determined in the absence of conjunctival pallor when patients are suffering from fatigue, lethargy, dizziness, headache, depression, cognitive impairment, and exertional dyspnea, which are frequent symptoms of chronic anemia with Hb levels between 8–12 g/dl. Hb levels below 8 g/dl are usually associated with markedly reduced exercise capacity, difficulty breathing at rest, and rapid or irregular heartbeat at rest. There is also an increased risk of angina pectoris, myocardial infarction, and transient ischemic events (Barrett-Lee et al. 2000; Cella 1997, 1998; Groopman and Itri 1999; Sobrero et al. 2001; Yellen et al. 1997) (see also Chapter 13).