Association between the Naples prognostic score and survival of patients diagnosed with stage IV lung cancer complicated by pulmonary infection

Objective To assess the association between the Naples Prognostic Score (NPS) and survival in stage IV lung cancer patients with pulmonary infection. Methods We conducted a retrospective analysis of 327 patients with stage IV lung cancer and pulmonary infection from January 2022 to January 2024. Data collected within 24 hours of admission included basic information, laboratory indices, and survival status. The NPS, calculated from albumin, total cholesterol, neutrophil/lymphocyte ratio, and lymphocyte/mononuclear cell ratio, was compared between survival and death groups. Logistic regression analyses identified biomarkers associated with in-hospital death risk, and the ROC curve evaluated the predictive efficacy of NPS and biomarkers. Subgroup analysis focused on patients receiving adjuvant immunotherapy. Results The cohort had a mean age of 73 ± 10 years, with 55.96% males. In-hospital mortality was 12.5% (41/327). Patients who died had significantly higher WBC, DD, CRP, and NPS levels upon admission (P < 0.05). NPS (OR = 1.11, 95%CI: 1.02–1.27, P = 0.02) and DD (OR = 1.04, 95%CI: 1-1.1, P = 0.04) were significantly linked to in-hospital mortality, particularly in immunotherapy patients. The AUC for NPS was 0.75, and combining NPS with DD increased the AUC to 0.81 (P < 0.001). Conclusion NPS at admission is significantly associated with survival outcomes in stage IV lung cancer patients with pulmonary infection, especially among those receiving immunotherapy. The combination of NPS and DD levels improves predictive accuracy, benefiting clinical decision-making and patient management.