Anemia and fatigue in cancer patients

Abstract

Although strong evidence indicates that fatigue can be caused by anemia, little is known about the relationship between the extent and rate of hemoglobin loss and the development of fa tigue. Anemia, an insufficiency of red blood cells to maintain adequate tissue oxygenation, is the most common hematologic abnormality associ ated with cancer. It usually results from a de crease in red blood cell production, resulting from either direct tumor invasion of bone mar row or the anemia of chronic disease. Fatigue is a subjective sensation, often described as tired ness, exhaustion, lethargy, or malaise. The mechanism that precipitates or sustains fatigue is probably multifactorial and includes the re lease of inflammatory cytokines and the onset of the acute-phase inflammatory response. Other factors that contribute to cancer-related fatigue include the underlying disease, treatment of the disease, intercurrent systemic illnesses, sleep disorders, immobility and lack of exercise, chronic pain, and psychosocial factors. A review of cancer-related anemia and fatigue is pre sented, which focuses on the clinical decision- making process regarding the management of these syndromes when they exist concurrently.