Abstract:
Objective To explore the effects and impacts on peripheral blood immunosuppressive cell of first-line and second-line immunotherapy on non-small cell lung cancer (NSCLC).
Methods From January 2018 to October 2019, 27 patients with NSCLC were selected from Zhongshan Hospital, Fudan University. Seven were treated with first-line immunotherapy with PD-1 inhibitors, and 20 were treated with second-line immunotherapy. The clinical efficacy of PD-1 inhibitor first-line and second-line immunotherapy in 27 patients with NSCLC were analyzed, and the effects of different therapies on the main immune suppressor cells in peripheral blood including monocytic myeloid-derived suppressor cells (M-MDSCs), granulocytic myeloid-derived suppressor cells (G-MDSCs), and regulatory T cells (Tregs) were examined.
Results Among the first-line immunotherapy patients, 57.1% (4/7) had partial response (PR), 28.6% (2/7) had stable disease (SD), and 14.3% (1/7) had progressive disease (PD). Among the second-line immunotherapy patients, 15% (3/20) had PR, 55% (11/20) had SD, and 30% (6/20) had PD. Flow cytometry analysis showed that M-MDSCs in the first-line PD-1 inhibitor treatment group decreased significantly after the treatment, while there was no significant change in the second-line immunotherapy group. Furthermore, after the first cycle treatment, the first-line treatment group had lower levels of M-MDSCs than the second-line treatment group (P < 0.05), indicating lower immunosuppressive activity caused by M-MDSCs in the former group, whereas there was no corresponding change in G-MDSCs. In contrast, the level of Tregs increased significantly in both groups, especially in the second-line immunotherapy group. Moreover, the correlation analysis proved that the decline of M-MDSCs was related to the therapeutic effect (r=-0.04, P < 0.05), while the Tregs increase was not.
Conclusions Patients with advanced NSCLC receiving first-line immunotherapy have a better clinical therapeutic effect and lower level of immunosuppressive activity in the peripheral microenvironment than those receiving second-line immunotherapy.