Abstract
The prognostic nutritional index (PNI) has been associated with disease progression and overall survival among cancer patients. Nonetheless, the association between PNI and mortality risk in adult cancer patients within the United States remains unexplored. This study aims to elucidate the connection between PNI and prognostic outcomes in American adult cancer patients. This cohort study derived data from the National Health and Nutrition Examination database, involving 4366 American adults diagnosed with cancer between 1999 and 2018. The nutritional status was assessed using the PNI, with higher PNI scores indicating a more favorable nutritional status. The study employed Kaplan-Meier curves and Cox proportional hazard regression to investigate the impact of PNI on various outcomes, including all-cause mortality (ACM), cardiovascular mortality (CAM), and malignancy tumor mortality (MTM) among adult cancer patients. Furthermore, restricted cubic spline models were used to examine the potential nonlinear relationship between the variables by creating hazard ratio (HR) curves at four specific points. The median follow-up duration was 84 months, during which 1530 (35.04%) cases of ACM occurred, including 331 (13.67%) CAM and 449 (10.45%) MTM. COX regression analysis revealed a significant inverse association between PNI and patient prognosis, with HRs of 0.95 (95% CI: 0.93-0.96, p < .001) for ACM, 0.93 (95% CI: 0.90-0.96, p < .001) for CAM, and 0.94 (95% CI: 0.91-0.97, p < .001) for MTM. Both Kaplan-Meier analyses and restricted cubic spline curves showed significant differences in mortality rates related to PNI (p < .001, nonlinear p < .001). Our study provides compelling evidence of a clear association between PNI and reduced risk of ACM, CAM, and MTM in adult cancer patients in the United States. These findings underscore the significance of incorporating PNI as a possible prognostic indicator for individuals diagnosed with cancer.