Cognitive function in long-term survivors after treatment for brain metastases compared with normative samples

Abstract

Background Few studies have examined cognitive function in long-term survivors with brain metastases (BM). The aim of this study was to assess performance-based cognitive function and compare it with normative samples. Methods Patients with ≥2-year survival after a first-time BM diagnosis completed neuropsychological tests assessing the following neurocognitive domains: processing speed, executive functioning, mental flexibility, visual learning and memory, verbal learning and memory, attention, and working memory. Test scores were converted into standardized z-scores using normative sample means and standard deviations (SD). The proportions of patients with an individual z-score of ≤−1 and ≤−1.5 SD below the normative sample means were calculated to indicate subclinical and clinically significant impairment. Results Forty-one patients (median age 58, 24 women) completed assessments at a median of 32 months (min–max: 26–47) after the BM diagnosis. On a group level, patients performed poorer than normative samples in tests within all domains except verbal learning and memory. The deviation was most pronounced in a subtest assessing mental flexibility. The proportion of patients with subclinical or clinically significant impairment ranged from 29% to 59% and 7% to 51% between domains, respectively. Seventy-three percent had at least subclinical and 59% had clinically significant impairment in at least 1 domain. Conclusions Long-term survivors with BM performed poorer than normative samples within nearly all neurocognitive domains, particularly executive functioning and mental flexibility. This domain is important for daily living and social functioning, and clinicians should provide information about the implications of BM and tailor patient care to optimize functioning and quality of life.