Scientists at Moffitt Cancer Center found that the study participants on average had mild impairments in verbal abilities such as difficulty choosing words and visuospatial abilities like getting lost more easily.
The study noted that cognitive functioning varies across survivors, with some reporting no impairments and others reporting more severe or pervasive deficits.
"The objective of our analysis was to clarify existing research on cognitive functioning in patients who had received standard dose chemotherapy for breast cancer at least six months previously," said study lead author Heather S L Jim.
"Earlier studies had reported conflicting evidence on the severity of cognitive deficits, especially over the long term," Jim said in a statement.
Although this is an active area of research, an overall analysis of the studies had not been performed since 2006, explained the researchers.
"Our analysis indicated that patients previously treated with chemotherapy performed significantly worse on tests of verbal ability than individuals without cancer," said co-author Paul B Jacobsen.
"In addition, patients treated with chemotherapy performed significantly worse on tests of visuospatial ability than patients who had not had chemotherapy," he said.
Jim suggested that breast cancer patients treated with chemotherapy who have subsequent cognitive deficits should be referred to a neuropsychologist for evaluation and management of the deficits.
"Management usually involves developing an awareness of the situations in which their cognitive difficulties are likely to arise so that they can come up with strategies to compensate. Research shows that such strategies can make a big difference in daily life when cognitive difficulties do arise," he added.
The study was published in the Journal 'Clinical Oncology'.
