A Comparative Study of the Efficacy and Safety of Immune Monotherapy versus 
Immunotheray Combined with Chemotherapy in Elderly Patients Aged 75 Years 
and Above with Advanced Non-small Cell Lung Cancer

Abstract

Background and objective The malignant tumor that has the highest global morbidity and death rate is lung cancer, which primarily affects the elderly. The therapy landscape for non-small cell lung cancer (NSCLC) has transformed with the introduction of immune checkpoint inhibitors (ICIs). The purpose of this study was to compare the safety and efficacy of immune monotherapy and immunotheray combined with chemotherapy in patients with advanced NSCLC aged 75 years and above. Methods This study retrospectively analyzed 111 patients with advanced NSCLC who were at least 75 years old and received treatment at the First or Fifth Medical Centers of the People's Liberation Army General Hospital from January 2018 to October 2022. These patients underwent first-line or second-line treatment, with 70 receiving immunotherapy combined with chemotherapy and 41 receiving immunotherapy alone. Propensity score matching (PSM) was used to match the baseline characteristics of the patients, including age, Eastern Cooperative Oncology Group performance status (ECOG PS) score, and the number of treatment lines. The study endpoints included objective response rate (ORR), progression-free survival (PFS), overall survival (OS), and safety assessment. Results The median OS for the immunotherapy combined with chemotherapy group was 27.87 months, and the median PFS was 11.50 months. The median OS for the immune monotherapy group was 34.93 months, and the median PFS was 17.00 months. There were no significant differences in OS (P=0.722) and PFS (P=0.474) between the two groups, but a significant difference was observed in ORR (P=0.025). After PSM matching, each group comprised 27 patients. The median OS for the immunotherapy combined with chemotherapy group was 17.70 months, the median PFS was 8.97 months. The median OS for the immune monotherapy group was 17.87 months, and the median PFS was 11.53 months. No significant differences were observed in OS (P=0.635), PFS (P=0.878) and ORR (P=0.097). In terms of safety, the overall incidence of adverse events (AEs) before matching was 62.86% in the immunotherapy combined with chemotherapy group, which was higher than 41.46% in the immune monotherapy group (P=0.029), while there was no difference in the incidence of AEs of grade 3 or above between the two groups (P=0.221). After matching, AEs occurred in 17 (62.96%) patients in the immunotherapy combined with chemotherapy group and 13 (48.15%) in the immune monotherapy group. There were no significant differences in the overall incidence of AEs (P=0.273) or the incidence of grade 3 or above (P=0.299) between the two groups. Conclusion Immunotherapy combined with chemotherapy does not significantly improve OS or PFS in patients with NSCLC aged 75 years and above when compared to immunotherapy alone, and this conclusion was further validated by the analysis after PSM. The safety assessment suggests that before matching, the incidence of AEs of any grade in the immunotherapy combined with chemotherapy group was higher. Still, the two groups had no difference in the incidence of AEs of grade 3 or above. Following matching, the tolerability of the treatment was similar in both groups. According to the safety assessment, the unique circumstances and course of treatment for geriatric patients with advanced NSCLC should be considered.

Keywords

• lung neoplasms
• the elderly patients
• immunotherapy