Prognostic impact of the timing of immunotherapy in first‐line immunochemotherapy for patients with advanced lung adenocarcinoma: A propensity score‐matched analysis

Immunochemotherapy combinations have been the standard first-line therapy for advanced lung adenocarcinoma (LUAD) without driver mutations, wherein concurrent chemotherapy and immunotherapy are conventionally anchored in the established dosing regimen. A few studies have suggested that the timing of immunotherapy in combinations may have a significant impact on the efficacy. However, this issue has not been addressed in an advanced LUAD cohort. We aimed to investigate the prognostic significance of the timing of immunotherapy in first-line immunochemotherapy combinations for patients with advanced LUAD. We retrospectively analyzed 508 patients with advanced LUAD without driver mutations who received immunochemotherapy as initial systemic treatment. The patients were divided into two groups-the induction and non-induction groups-with induction defined as receiving chemotherapy alone before concurrent immunochemotherapy. The bias between different groups was minimized using propensity score matching (PSM). We found both the PFS and OS of the patients in the induction group were significantly longer than those in the non-induction group before (PFS: p < 0.0001, OS: p < 0.0001) and after PSM (PFS: p = 0.0045, OS: p = 0.00073). After adjusting for confounders, induction chemotherapy was still a significant favorable factor for both PFS (p = 0.001) and OS (p = 0.001). In subsequent analyses, we found that both ≥2-cycles induction (PFS: p = 0.000, OS: p = 0.000) and 1-cycle induction (PFS: p = 0.013, OS: p = 0.002) were superior to non-induction and these differences were still significant after PSM. Our findings highlight the notable benefits of induction chemotherapy for patients with advanced LUAD treated with first-line immunochemotherapy combinations.