Lately, there has been a great evolution of immunotherapy in non-small cell lung cancer (NSCLC) due to its relationship with inflammation. There is also a growing interest in the changes produced in immune system with age (immunosenescence). However, it is unclear if these differences also exist among elderly patients with cancer compared to adult patients with the same diagnosis and this is the aim of our study.
We retrospectively studied patients diagnosed of NSCLC during January-December 2017 at the time of diagnosis, excluding patients with chronic infections or autoimmune diseases. Included cases were divided into two groups depending on age. Lymphocyte count by flow cytometry was gathered at baseline and we studied if there were statistically significant differences in lymphocyte populations between young (<70) and elderly patients (≥70). The non-parametric Mann-Whitney test was used.
81 patients were analysed; 32 in the young group and 49 in the elderly group. Regarding the innate immunity, the median value of NK lymphocytes showed to be higher in the cohort of patients ≥70 years (295 vs 191 cells/mm3; p = 0.0014). Oppositely, the median value of B-lymphocytes was lower in elderly patients (99 vs 128 cells/mm3; p = 0.0282). The Spearman coefficient for the correlation between age and B-lymphocyte count supports this data: ρ = 0.36 (moderate association). However, there was no difference between the median values of T-lymphocytes (p = 0.142). Interestingly, analysing T-lymphocyte subsets we found that median CD8 value was higher in the elderly group (464 vs 309.5 cells/mm3; p = 0.0226) but there was no difference in the CD4-lymphocyte subset (p = 0.4928).
Our results are similar to the ones reported in non-oncologic population, such as an increased number of NK-lymphocytes in elderly patients and a lower count of B-lymphocytes. Therefore, signs of immunosenescence can be seen in patients with NSCLC. However, subpopulations of lymphocytes show more accurately cell functionality. This is why we are performing deeper research regarding the changes in immune system produced with age in oncologic patients.
Clinical trial identification
Legal entity responsible for the study
Doctor Peset University Hospital.
Has not received any funding.
All authors have declared no conflicts of interest.