[Clinical Observation of Immunotherapy Efficacy and Adverse Effects in Chinese Patients with Lung Squamous Cell Carcinoma].

BACKGROUND

Immune checkpoint inhibitors (ICIs) improved survival of partial patients with lung squamous cell carcinoma (LUSC). However, it was still insufficient of data in older patients. This study aimed to investigate the efficacy and toxicity of immunotherapy in patients with LUSC in Chinese population of real world.

METHODS

A total of 185 LUSC patients underwent pathological diagnosis were involved from January 2018 to January 2022. Patients were divided into elderly group (age ≥70 years) and younger group (age <70 years). The efficacy of mono-immunotherapy or combined with chemotherapy to chemotherapy in first-line treatment was compared. The expression of programmed cell death ligand 1 (PD-L1) and tumor mutational burden (TMB) were evaluated. Response Evaluation Criteria in Solid Tumors (RECIST) version 1.1 was used to evaluate the efficacy, and Common Terminology Criteria for Adverse Events (CTCAE) version 4.03 was used to evaluate immune-related adverse. Kaplan-Meier and Log-rank test was performed. Cox regression was used in prognostic analysis.

RESULTS

Combined therapy acquired significantly higher overall response rate (ORR) compared with chemotherapy alone in elderly group (P<0.05), and also in younger group, despite the difference was not significant (P>0.05). The median progression-free survival (mPFS) and median overall survival (mOS) in elderly group were similar with younger group (P>0.05). Both combined group and immunology alone demonstrated prolonged mPFS in first-line compared with chemotherapy in elderly group. And combined group demonstrated significantly prolonged mPFS compared with chemotherapy in younger group (P<0.01). There was no difference of mOS between different regimes in two groups. Elderly LUSC patients had higher PD-L1 positive rate (≥1%) and similar TMB compared with younger group. There was no relationship between mPFS and mOS with the expression of PD-L1 and TMB. Immunology combined with chemotherapy demonstrated better mPFS compared to chemotherapy in first-line therapy with TMB-High (P<0.05), and inferior mPFS with TMB-Low despite the difference was not significant (P>0.05). Cox regression model demonstrated that clinical stage was an independent predictor and prognostic factor. The incidence of immune-related adverse was 58.0% (51/88) and grade 3 or above 25.0% (22/88). The most common grade 3 adverse events were rash, immune-associated pneumonia, and fatigue.

CONCLUSIONS

Immunology combined with chemotherapy increased ORR, mPFS and mOS of Chinese patients with LUSC in first-line therapy compared with chemotherapy. There was no difference of efficacy and adverse effects rate between elderly group and younger group. The adverse effects of immunology in elderly patients with LUSC were controllable.