Survival Outcomes Associated With Short‐Acting Versus Long‐Acting G‐ <scp>CSF</scp> Use During First‐Line Chemoimmunotherapy for Advanced Lung Cancer: A Retrospective Study

While granulocyte colony-stimulating factor (G-CSF) is used to prevent and treat chemotherapy-induced neutropenia, it also regulates key immune cells and may therefore affect the efficacy of immunotherapy. Short-acting and long-acting G-CSF have similar efficacy in managing neutropenia, but they differ in effects on immune cells. However, the overall impact of G-CSF and its different formulations on survival in advanced lung cancer patients receiving chemoimmunotherapy remains unclear. This retrospective study enrolled patients with advanced primary lung cancer receiving first-line chemoimmunotherapy at Tianjin Medical University Cancer Institute and Hospital. The primary outcome was overall survival (OS). Inverse probability of treatment weighting (IPTW) was used to balance heterogeneity between groups. Kaplan Meier and Cox models were used to estimate OS and progression-free survival (PFS). Among 606 patients, 308 developed neutropenia and received G-CSF support (pegylated recombinant human G-CSF [PEG-rhG-CSF]: 183; recombinant human G-CSF [rhG-CSF]: 125); 298 without neutropenia received no G-CSF. After IPTW, no significant differences in PFS and OS were observed between G-CSF group and non-G-CSF group. Patients receiving rhG-CSF had significantly improved OS (42.6 vs. 28.2 months, p = 0.041) and PFS (15.4 vs. 9.4 months, p < 0.001) than those receiving PEG-rhG-CSF. Multivariable analysis confirmed rhG-CSF as a favorable independent prognostic factor for both PFS and OS. Among patients with advanced primary lung cancer receiving first-line chemoimmunotherapy, G-CSF support effectively abrogates the adverse survival impact of chemotherapy-induced neutropenia. Moreover, rhG-CSF was associated with improved clinical outcomes versus PEG-rhG-CSF. Prospective randomized trials are required to validate these findings and guide clinical practice.