Effects of different doses and sites of radiotherapy on immune cell
subsets in peripheral blood of patients with lung cancer
Abstract
Objectives: Few studies focused on the effects of radiation for
different metastatic sites or radiotherapy doses on immune cell subsets.
Therefore, this study investigated the effect of different irradiation
doses and sites on the systemic immunity of patients with lung cancer.
Method: Peripheral blood samples from 48 patients with lung cancer were
collected, and the lymphocyte subsets were examined by flow cytometry.
Results: In patients with non-small cell lung cancer (NSCLC) who
received thoracic radiotherapy, the percentage of B lymphocytes after 20
fractions of radiotherapy was significantly lower than that recorded
after 10 fractions (P=0.0046). In addition, the CD4+ naïve T-cell
subsets at each different detection time point were significantly lower
than the baseline (P=0.0304, <0.0001, <0.0004,
respectively). In NSCLC patients with brain metastases who received
brain radiotherapy, the percentage of B lymphocytes was significantly
lower than the baseline (P=0.039). In patients with SCLC who received
radiotherapy for the primary tumor, the percentage of CD4+ naïve T-cell
subsets after 20 fractions was significantly lower than that observed
after 10 fractions of radiotherapy (P=0.0444). There was no significant
difference in other lymphocyte subsets at different time points or
irradiated sites. Conclusion: Radiotherapy has a certain
immunosuppressive effect. In addition, thoracic radiotherapy has an
inhibitory effect on the proportion of T cells, whereas it does not
significantly affect the proportion of T cells when irradiation of
metastatic sites. It is suggested that the dose of radiotherapy in other
metastatic organs of patients with lung cancer needs to be further
escalated.