NEW YORK (Reuters Health) Jun 21 - More than a third of women with breast cancer may exhibit some degree of cognitive impairment before receiving systemic chemotherapy, according to a report in the June 21st online edition of Cancer. The findings suggest that the disease itself, or associated conditions, may be responsible for so-called "chemobrain," say the authors.

Chemotherapy has been associated with changes in cognitive functioning in women with breast cancer, the authors explain, but pretreatment measures of neuropsychological functioning have rarely been taken into account.

Dr. Christina A. Meyers from The University of Texas M. D. Anderson Cancer Center, Houston, Texas and colleagues evaluated data from three separate studies that examined the effects of hormonal treatments and chemotherapeutic treatments on cognitive functioning in a population of women with non-metastatic breast cancer, all of whom underwent a comprehensive neuropsychological evaluation before treatment.

Approximately 35% of women were classified as having an impaired Overall Cognitive Function Index before initiation of adjuvant chemotherapy, the authors report. Changes were most evident in verbal learning and verbal memory, as well as one measure of psychomotor processing speed and attention. About a quarter of the women reported symptoms of anxiety and/or depression sufficient to result in a classification of clinically significant distress, the report indicates. These women were also more likely to manifest cognitive impairment.

Women with cognitive impairment did not differ significantly with regard to age, educational level, or other demographic, disease-related, or treatment-related variables, the researchers note, though women who were postmenopausal, had no history of receiving hormone replacement therapy, or had undergone lumpectomy/mastectomy were nearly twice as likely to be cognitively impaired as were women lacking these characteristics.

"Chemobrain is real," Dr. Meyers told Reuters Health. "It can be caused by the cancer, the cancer treatment, or other underlying medical conditions (borderline anemia, thyroid dysfunction, etc.), and it can be treated."

"My advice to patients is 'tell your doctor' because there are a number of things that can cause symptoms, so identification of what is wrong and why is important to guide interventions," Dr. Meyers said. "And we do have a number of interventions to attenuate the impact of adverse symptoms on the patients' ability to function."

Dr. Meyers concluded, "Our research direction now is looking at how these symptoms develop and who gets them (e.g., host genetic susceptibility, inflammatory response caused by the host immunologic response to cancer, what the cancer cells are producing, etc.), so we can develop targeted and effective treatment."

Dr. Lemmo's Comments

References

1. Cancer 2004.