''Chemo brain'' unrelated chemotherapy for breast cancer

NEW YORK, jUNE 16 (Reuters) Drug therapy given before the primary chemotherapy for breast cancer does not appear to worsen mental processes, or ''cognitive function,'' German investigators report in the journal Cancer. Suspicions that it does may have been influenced by cases of mental decline that occurred before treatment began.

''Most evidence of so-called chemo brain (or chemo fog) comes from cross-sectional studies without pre-chemotherapy assessment,'' Dr Kerstin Hermelink from Ludwig-Maximillian University, Munich, told Reuters Health. ''In these trials, cognitive compromise present already after diagnosis might mistakenly have been attributed to chemotherapy effects.'' Hermelink and colleagues assessed the course of cognitive function before and after exposure to cytostatic treatment in just over 100 women with breast cancer.

Before the start of therapy, the average scores for 5 of 12 cognitive tests were below normal, the authors report, and the group's average score for one test was better than the norm.

Twenty-one weeks later, toward the end of chemotherapy, there was an overall improvement in scores that reached statistical significance in six tests. Only one test showed significant deterioration after chemotherapy.

Excluding patients with confounding factors, 22 per cent showed predominant deterioration, and 32 per cent showed predominant improvement after chemotherapy, the researchers note.

Age and intelligence were not associated with the change in test results, the report indicates. And while anxiety and depression did not correlate with the change in test results, but they did correlate with self-reported cognitive complaints.

''Breast cancer patients who decline chemotherapy for fear of cognitive impairment should be informed that cognitive compromise often occurs already in the wake of diagnosis,'' Hermelink said.

''During chemotherapy, cognitive function is stable in most patients, and decline is as likely as improvement.'' Nevertheless, ''More research is necessary before patients can be reassured that chemotherapy does not impair cognitive function,'' Hermelink said, adding that results of the 1-year follow-up should be available soon.

REUTERS JK RS0844