Every Day
January - April 2008 Issue
Cancer and Cancer Treatment May Affect Thinking Ability
David S. Sabsevitz, PhDMedical College of Wisconsin Neuropsychologist
Neuro-Oncology Cognitive Clinic
When someone has cancer, he or she may experience a lesser known side effect of the disease and/or treatment. The side effect involves changes in cognition — a person’s ability to think. Dr. David Sabsevitz discusses how cancer and cancer treatment can affect the way the brain works.
Q. What is cognition?Cognition is a broad term that refers to our ability to think, reason and perceive. It includes such mental abilities as attention, memory, language and problem-solving to name a few.
Q. How do cancer and cancer treatments affect cognition?Cancer can affect cognition in many different ways. When cancer is in the brain, it can alter the way the brain works and cause a wide variety of cognitive symptoms. With only a limited amount of space in the skull, a brain tumor can alter cognition by placing pressure on surrounding healthy brain tissue as it grows and in the process disrupt the functioning of that brain area. Brain tumors can also spread into healthy tissue and in doing so damage those brain cells. The size and location of the tumor largely determine the type of cognitive symptoms experienced. There is also some evidence to suggest that cancer outside of the brain can affect the way we think although much less is known about what causes this change.
Cancer treatments can also affect cognition. When cancer is in the brain, surgery can be used to remove the tumor or as much of the tumor as possible. During surgery, healthy brain tissue near the tumor may be damaged. Surgical removal of healthy brain tissue, which is often unavoidable when removing a brain tumor, may cause cognitive changes directly attributable to the area of the brain removed or damaged.
Chemotherapy is used to treat a wide range of cancers and has been shown to be effective in killing cancer cells; however, chemotherapy can also damage healthy cells. The type and dose of chemotherapy, how long treatment lasts and whether it is combined with other forms of treatment seem to play a role in determining risk for cognitive problems. It is estimated that at least 30 percent of women who receive chemotherapy to treat breast cancer experience cognitive changes during and, in some cases, for some time after chemotherapy. Chemotherapy for other types of cancers can also affect cognition. The effect of chemotherapy on the brain is sometimes referred to as “chemobrain” or “chemofog.”
How chemotherapy affects the brain is not well-understood and research is currently going on to help answer this question.
Radiation therapy is also used to treat cancer. When radiation is directed to the brain, such as in the treatment of brain cancer or when used to reduce the chances of cancer spreading to the brain from other areas of the body, changes in cognitive can occur. Radiation therapy can alter our thinking by damaging the tissue in our brain, in particular, the “white matter” of the brain, which is very important for rapid communication between brain regions.
Finally, physical side effects of the cancer and cancer treatments, such as fatigue, pain, and other forms of discomfort, psychological distress associated with having cancer and undergoing cancer treatments, medical complications such as seizures, anemia, or endocrine dysfunction, and certain medications used to treat these side effects and complications can also cause cognitive symptoms.
Q. What are some typical cognitive problems?It varies from patient to patient and largely depends on where the cancer is located and what treatments the patient is undergoing and/or has completed. Commonly reported cognitive problems include difficulty concentrating, inability to multitask, mental slowing, memory loss, problems understanding or problems organizing thoughts.
Q. Do all cancer patients experience cognitive problems?No. Not all patients will experience cognitive symptoms as they go through treatment. In fact, many patients do not experience changes in their thinking and in some cases, cognition can actually improve while going through treatment, such as when a brain tumor shrinks in response to treatment.
Q. What is the role of a neuropsychologist in treating a person with cognitive problems?A neuropsychologist specializes in evaluating and understanding the effect of brain injury on behavior and cognition. He or she evaluates patients for cognitive changes, recommends treatment and identifies ways to help a patient relearn and/or compensate for impaired cognitive functions.
Q. What kinds of treatments are available for cognitive problems?Medications are available that can help improve attention and memory as well as lessen fatigue in cancer patients. Speech therapy and cognitive rehabilitation can be used to retrain damaged areas in the brain and help patients learn strategies to work around their cognitive problems. A psychotherapist can also help patients cope with emotional issues related to their disease and/or treatment. All of these specialists are part of the care team at Froedtert & the Medical College of Wisconsin.
Source: Every Day Date: Jan - April 2008 Issue |