Perceived cognitive function in breast cancer survivors: evaluating relationships with objective cognitive performance and other symptoms using the functional assessment of cancer therapy-cognitive function instrument

Context: Perceived cognitive impairment (PCI) has been shown to be one of the most common symptoms after breast cancer treatment. However, this symptom does not always correlate with objective cognitive performance and is often highly associated with other patient-reported symptoms.

Objectives: Using a sample of breast cancer survivors (BCS), this study examined relationships among the Functional Assessment of Cancer Therapy-Cognitive (FACT-Cog) scale, a self-report questionnaire that measures PCI; impact on quality of life (QoL); comments from others (other); perceived cognitive ability (PCA); objective cognitive performance on tests of verbal memory, speed of processing, and executive functioning; and other symptoms (fatigue, depression, anxiety, and sleep disturbance).

Methods: The BCS who were aged 40 years or older and at least one year post-chemotherapy treatment were enrolled. Participants completed questionnaires and a brief neuropsychological assessment.

Results: A total of 88 BCS who were on average 56.7 (SD 8.5) years old and 5.3 (SD 4.1) years post-treatment participated; 94% reported clinically significant PCI. The PCI was significantly correlated with some objective measures of immediate and delayed verbal memory and executive function, whereas PCA was associated with all these measures. The PCI and PCA were both significantly associated with depressive symptoms, fatigue, and anxiety, but only PCI was related to poor global sleep quality.

Conclusion: The PCA was highly correlated with objective neuropsychological performance and may be clinically useful in identifying problems with verbal memory and executive functioning in BCS.