Clinical Study Of PD-L1 Inhibitor Combined With Chemotherapy In The Treatment Of Extensive Stage Small Cell Lung Cancer

Objectives:To investigate the clinical efficacy,safety,and hematological related indexes of PD-L1inhibitor combined with chemotherapy in the treatment of extensive stage small cell lung cancer.Methods:From January 2020 to December 2021,a total of 40 patients who were newly diagnosed with extensive stage small cell lung cancer in the First Hospital of Jilin University were selected.And the 40 patients were divided equally into two groups,one group was controlled and the other was observed.The first group of patients which were controlled was treated with the platinum-etoposide regimen,and the other group of patients that were observed was treated with the platinum-etoposide and duvalizumab.After the 40 patients were treated for 12 weeks,which lasted for 4 courses,the clinical efficacy,tumor markers,lymphocyte subsets of the two groups were compared.After 2 and 4 courses of treatment,NLR and PLR ratios were compared,and during the treating courses,the adverse reactions of the 40 patients were observed.Results:1.The clinical curative effect of the observed group was better than that of the controlled group,and the difference was statistically significant（P<0.05）.2.After 4 courses of treatment,the level of NSE in the observed group was obviously lower than that before treatment and that in the controlled group（P<0.05）.However,there were no significant differences in the levels of CEA and CYFRA21-1 between the observed group and the controlled group,and the same was true compared with the observed group before treatment.3.After 4 courses of treatment,the CD3⁺T lymphocyte percentage,CD19⁺B lymphocyte percentage,CD16⁺56⁺NK cell percentage,and CD4⁺/CD8⁺T lymphocyte ratio of the observed group were significantly higher than those of the controlled group（P<0.05）.4.After 2 and 4 courses of treatment,the NLR of patients in the observed group were significantly lower than those before treatment and the same period in the controlled group（P<0.05）.However,after 2 and 4 courses of treating,there was no significant difference in PLR between the observed group and the controlled group,and the same was true compared with the observed group before treatment.5.The incidences of adverse reactions between the two groups during treatment were no significant difference（P>0.05）.In the observed group,the incidence of immune-associated hypophysitis was 15%,and the incidence of immune-associated thyroid disorders was 10%.All the patients which had immune-related adverse events had no obvious clinical symptoms and belonged to low-level adverse reactions.Conclusions:Duvalizumab combined with chemotherapy has better clinical efficacy than chemotherapy alone in the treatment of newly diagnosed extensive stage small cell lung cancer patients.It can significantly reduce the level of tumor marker NSE and enhance the immune function of patients,and the adverse reactions are no different from chemotherapy alone.However,the incidences of immune-associated hypophysitis and thyroid disorders are slightly higher during treatment,so the levels of endocrine hormones and related clinical symptoms should be closely monitored during treatment.NLR ratio is expected to be one of the indicators to predict the prognosis of immunotherapy in patients with small cell lung cancer.