Cognitive impairment is related to a reduced count of T-lymphocytes in older patients diagnosed with non-small cell lung cancer (NSCLC)

Background: Aging is a risk factor for cancer and cognitive impairment, and both have been related to changes in the immune system (immunosenescence) and chronic inflammation (inflammaging) of elderly individuals. Therefore, it would be interesting to know if there is a connection between immunological variations and cognitive function in oncologic patients, especially in lung cancer, in which, inflammation plays a crucial role in tumor development and progression. Our objective is to assess, in older patients diagnosed with non-small cell lung cancer (NSCLC), differences in parameters of the immune system depending on their cognitive status. Methods: We retrospectively analyzed patients >= 70 years diagnosed with NSCLC with evaluated cognitive function, from January 2017 to April 2019. Lymphocyte count was gathered at baseline and checked for differences in lymphocyte counts between patients with a Pfeiffer result of 0-2 vs. 3-10 mistakes. Multiple regression models were used to assess the impact of clinical parameters on lymphocyte count. Results: Seventy patients were analyzed. Sixty had a normal cognitive function, while ten had an impaired cognitive status; these were significantly older. Multivariate analysis showed that patients with cognitive impairment had lower levels of total, T and CD8+ T-lymphocytes (P=0.011, 0.011 and 0.019, respectively). Older age was only correlated to higher level of CD8+ T-lymphocytes (P=0.0390). Odds ratio for the risk of cognitive impairment depending on the level of T-lymphocytes was 0.996 (95% CI: 0.995-0.998), P=0.037. Conclusions: T-lymphocyte count is lower in patients diagnosed with lung cancer and cognitive impairment. These findings suggest that clinical features are closely related to immunological status in older patients with NSCLC. Therefore, age cannot always explain immunosenescence, and geriatric assessment could help.