Anemia: A Manageable Side Effect Gastrointestinal Stromal Tumors
In contrast to other common side effects experienced by patients undergoing treatment for cancer—such as nausea and vomiting, diarrhea, and hair loss—anemia is often a “silent” side effect with insidious symptoms. Fortunately, a simple blood test can detect anemia, and effective treatment for the condition exists.
Anemia is an inadequate supply of red blood cells, resulting in a decrease in the oxygen carrying capacity of the blood. Chemotherapy, radiation therapy, and blood loss during surgery are all common causes of anemia in cancer patients. As chemotherapy drugs kill rapidly dividing cells in the body, they may destroy cancer cells and normal cells, such as those in the bone marrow responsible for red blood cell production. Red blood cells contain the protein hemoglobin, which carries oxygen to all parts of the body. Low levels of red blood cells, and the hemoglobin they contain, cause a reduction in the amount of oxygen that can be carried to the body. The decreased delivery of oxygen in anemia patients causes the following symptoms:
- Fatigue or tiredness
- Trouble breathing
- Rapid heartbeat
- Dizziness, light-headedness, inability to concentrate, or headache
- Chest pain
- Difficulty staying warm
- Loss of sex drive
- Pale skin
- Diminished cognitive function
Severe anemia may require blood transfusions, which have associated risks of infection, rejection, and increased medical costs. Furthermore, severe anemia may cause a delay in the delivery of cancer treatment, resulting in compromised chances of a cure or best possible long-term survival. However, anemia is a manageable side effect: Treatments are available to improve anemia and its symptoms.
Advances in Treatment
Two agents, Procrit® and Aranesp®, are currently available for the treatment of anemia in cancer patients. These agents stimulate the body to produce more red blood cells, ultimately reducing or completely reversing anemia. Aranesp is a longer-acting form of Procrit, meaning it produces the same results with less frequent dosing. Patients with anemia may also be treated with iron supplements.
Research is also focusing on the use of Aranesp or Procrit to prevent anemia from occurring altogether in patients who are considered at high risk of developing anemia. These risk factors include additional existing medical issues, starting therapy with a low hemoglobin level, or receiving a treatment associated with high rates of anemia.
Studies in Management of Anemia
Researchers associated with the National Central Cancer Treatment Group (NCCTG) recently conducted a study to evaluate treatment with Procrit in cancer patients receiving chemotherapy. This study included 330 patients with incurable cancer who had chemotherapy-related anemia. Patients either received Procrit once per week for 16 weeks or placebo (inactive substitute). During the study, only 25 percent of patients treated with Procrit required a red blood cell transfusion, compared to nearly 40 percent for those receiving placebo. Hemoglobin levels were significantly increased in nearly 73 percent of patients treated with Procrit, whereas only approximately 32 percent of patients who received placebo had raised hemoglobin levels. Overall, patients reported significantly less fatigue and an improved quality of life with increased hemoglobin levels.
The clinical study that prompted Federal Drug Administration (FDA) approval of Aranesp included over 300 patients with advanced cancer who were undergoing chemotherapy. Patients were treated with either Aranesp or placebo. Over a 12-week period, only 26 percent of patients treated with Aranesp needed blood transfusions, compared to more than twice that amount (60 percent) of patients who received placebo.
Several studies have verified the clinical impact of preventing anemia and the accompanying improved quality of life. Quality of life parameters typically include fatigue, cognitive function, ability to spend time with friends and family, and an improved outlook on life.
The Future of Anemia Treatment
Although anemia is a common and debilitating side effect often experienced by cancer patients, effective and convenient treatment is available. Fortunately, it is a side effect that is easily manageable with Aranesp or Procrit. As patients with cancer are living longer due to earlier detection and improved treatment, attention to quality of life is important; prevention or treatment of anemia in these patients may greatly improve their health and wellbeing. Results from future clinical trials will help physicians understand possible ways to prevent anemia in high-risk patients as well as understand the potential long-term effects of anemia and its treatment in patients with cancer.