Longitudinal assessment of cognitive function in patients with breast cancer and lymphoma receiving chemotherapy

Background Cancer-related cognitive impairment is a significant concern, yet data assessing long-term changes from pre-treatment baselines are limited. Methods In this large nationwide study, patients with breast cancer and lymphoma and controls were assessed at pre-chemotherapy, post-chemotherapy, 6-month, and 1- and 2-year follow-ups. Cognitive function was measured using self-reported and performance-based assessments. The analysis included 225 participants: breast cancer (41 patients/36 controls) and lymphoma (73 patients/75 controls). Cognitive trajectories were estimated using longitudinal linear mixed models, adjusting for demographic, clinical, and psychosocial factors. A minimal clinically important difference cut-off identified changes over time in perceived cognitive impairment. Results Patients with breast cancer reported greater cognitive complaints than controls, with declines in FACT-Cog Total (β = -17.17, p < .001), Perceived Cognitive Impairment (β = -11.09, p < .001), and Perceived Cognitive Abilities (β = -3.60, p = .03) from pre-chemotherapy to 2-year follow-up. Declines were observed in memory (RAVLT Immediate Recall: β = -1.53, p = .04), and executive function (phone fluency: β = -1.53, p = .02) at 1 year. Patients with lymphoma also showed more complaints, with declines in Perceived Cognitive Impairment (β = -6.19, p = .01), poorer RAVLT Immediate (β = -1.62, p < .001), Delayed Recall (β = -1.72, p < .001), and phone fluency (β = -2.46, p < .001) from pre-chemotherapy to 1-year follow-up. Conclusion Compared to controls, patients with breast cancer and lymphoma showed persistent cognitive worsening up to 1-year post-treatment, and patients with breast cancer reported perceived impairment at two years compared to controls.