Cognitive Impairment in Cancer Patients Treated with Immune Checkpoint Inhibitors: A Cross-Sectional Study

Background and Objectives: Immune checkpoint inhibitors (ICIs) have transformed cancer care, but their impact on cognition is unclear. This study examined the prevalence and clinical correlates of cognitive impairment in patients receiving ICIs. Materials and Methods: In this two-center, cross-sectional cohort of 189 adults with solid tumors treated with ICIs, cognitive function was assessed using the Montreal Cognitive Assessment (MoCA). Cognitive impairment was defined as MoCA ≤ 21. Age, sex, education, Eastern Cooperative Oncology Group (ECOG) performance status, treatment line, number of metastatic sites, and ICI exposure were compared between cognitive groups using chi-square tests. Univariate and multivariate logistic regression models were used to identify independent predictors of cognitive impairment. Results: The median age was 65 years and 73% of patients were male. Overall, 102 of 189 participants (54%) met criteria for cognitive impairment. Patients with impaired cognition were more often aged ≥65 years, female, and educated at or below high school level, and more frequently had ECOG ≥ 1, second- or later-line ICI therapy, and ≥2 metastatic sites (all p < 0.05). In multivariate analysis, independent predictors of cognitive impairment were age ≥ 65 years (OR: 2.98, 95% CI 1.45–6.12, p = 0.003), female sex (OR: 2.48, 1.09–5.67, p = 0.030), lower education (OR: 3.10, 1.35–7.07, p = 0.007), later-line therapy (OR: 3.51, 1.56–7.88, p = 0.002), ECOG ≥ 1 (OR: 3.38, 1.46–7.83, p = 0.004), and ≥2 metastatic sites (OR: 2.85, 1.37–5.90, p = 0.005). Conclusions: More than half of patients receiving ICIs exhibit objective cognitive deficits. Systematic cognitive screening in high-risk subgroups may allow for earlier recognition of impairment and more timely supportive care.