Abstract
BACKGROUND: Cancer-related cognitive impairment is a significant concern, yet data assessing long-term changes from pretreatment 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, 1-year, 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 cutoff 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 (Rey Auditory Verbal Learning Test [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 with controls, patients with breast cancer and lymphoma showed persistent cognitive worsening up to 1-year posttreatment, and patients with breast cancer reported perceived impairment at 2 years compared with controls.