Cognitive function prior to systemic therapy and subsequent well-being in older breast cancer survivors: Longitudinal findings from the Thinking and Living with Cancer Study.

OBJECTIVE: To investigate the relationships between self-reported and objectively measured cognitive function prior to systemic therapy and subsequent well-being outcomes over 24 months in older breast cancer survivors. METHODS: Data were from 397 women aged 60 to 98 diagnosed with non-metastatic breast cancer in the Thinking and Living with Cancer Study recruited from 2010-2016. Cognitive function was measured at baseline (following surgery, prior to systemic therapy) using neuropsychological assessments of attention, processing speed, and executive function (APE), learning and memory (LM), and the self-reported FACT-Cog scale. Well-being was measured using the FACT-G functional, physical, social, and emotional well-being domain scales at baseline and 12 and 24 months later, scaled from 0 (low) to 100 (high). Linear mixed-effects models assessed the relationships between each of baseline APE, LM, and FACT-Cog quartiles with well-being scores over 24 months, adjusted for confounding variables. RESULTS: At baseline, older survivors in the lowest APE, LM, and FACT-Cog score quartiles experienced poorer global well-being than those in the highest quartiles. At 24 months, older survivors tended to improve in well-being, and there were no differences according to baseline APE or LM scores. At 24 months, mean global well-being was 80.3 (95% CI: 76.2-84.3) among those in the lowest vs 86.6 (95% CI: 83.1-90.1) in the highest FACT-cog quartile, a clinically meaningful difference of 6.3 points (95% CI: 1.5-11.1). CONCLUSIONS: Among older breast cancer survivors, self-reported, but not objective cognitive impairments, were associated with lower global well-being over the first 2 years of survivorship.