Objective: Although the baseline prognostic nutritional index (PNI) is a well-known prognostic factor in lung cancer, the clinical significance of its fluctuation during treatment remains unclear. This study aimed to evaluate the prognostic value of dynamic changes in the PNI and to determine whether improvements in nutritional and immune status are correlated with survival outcomes. Methods: A total of 478 patients diagnosed with lung cancer were retrospectively analyzed. The PNI was calculated on the basis of serum albumin levels and total lymphocyte counts. The baseline value was termed PNI1, and the posttreatment value was termed PNI2. The dynamic changes in PNIΔ were categorized as increased, stable, or decreased. Relationships between these dynamic parameters and Overall Survival and Progression-Free Survival were assessed using Kaplan–Meier and Cox regression analyses. Results: The median follow-up was 19.9 months. Patients with higher PNI1 and PNI2 scores had significantly longer OS and PFS. Notably, patients who demonstrated an increase in PNIΔ during the treatment course had significantly longer overall survival than those with stable or decreased scores (p = 0.023). Multivariate analysis revealed that while cancer type and the posttreatment PNI (PNI2) were identified as independent prognostic factors (p = 0.007 for PNI2), the dynamic improvement in the PNI emerged as a critical indicator of a better clinical trajectory according to univariate analysis. Conclusion: This study demonstrates that the PNI is not merely a static baseline marker but also a dynamic biomarker that reflects the host’s response to treatment and disease. An increase in PNI values during treatment is associated with improved survival, suggesting that dynamic monitoring of nutritional and immune status provides valuable prognostic information for patient management in lung cancer patients.
Mingsar et al. (2026) studied this question.