Background: Curative thoracic radiotherapy (CTRT) with concurrent chemotherapy has been considered as standard treatment approach for stage-III non-small cell lung cancer (NSCLC). The hematological and esophageal toxicities that have been encountered during CTRT would affect the immunonutritional status of the patients. The aim of this study is to evaluate the prognostic value of the change in pre- and post-treatment prognostic nutritional index (PNI) in stage-III NSCLC patients.
Methods: Eighty seven consecutive stage III NSCLC patients' data were collected. Pre-radiotherapy (RT) and post-RT PNI values were calculated and the impact of prognostic value of PNI change on overall survival (OS) was evaluated by univariate and multivariate Cox regression analyses. A cutoff value of PNI change was obtained by receiver operator characteristic (ROC) curve analysis.
Results: The cutoff value was found to be a 22% decrease in PNI by ROC curve analysis in terms of effect on OS. The median OS of low and high PNI decrease groups were 22.5 and 16.5 months respectively (P = 0,001). In univariate and multivariate analyses PNI decrease of ≥ 22% was found to be an independent poor prognostic factor for OS (P = 0.012) and hazard ratio (95% confidence interval)= 2.05 (1.16-3.62).
Conclusion: The PNI change would be a convenient parameter to assess the immunonutritional status of the patient at the end of CTRT. A decrease of more than 22% of PNI value may predict poor prognosis.
Keywords: Prognostic factor; prognostic nutritional index decrease; stage-III non-small cell lung cancer (NSCLC); survival; thoracic radiotherapy.