# The prognostic significance of the geriatric nutritional risk index in postoperative parotid gland carcinoma

## TL;DR

This study shows that the Geriatric Nutritional Risk Index (GNRI) can predict survival outcomes in patients who have had surgery for parotid gland carcinoma.

## Contribution

The study identifies GNRI as an independent prognostic factor and develops new nomograms for predicting survival in postoperative parotid gland carcinoma patients.

## Key findings

- GNRI is an independent prognostic factor for postoperative parotid gland carcinoma patients.
- New nomograms for DFS and OS outperform traditional AJCC staging with C-indexes above 0.7.
- The nomograms show strong clinical utility with AUC scores exceeding 0.7 and positive decision curve analysis.

## Abstract

The impact of the Geriatric Nutritional Risk Index (GNRI) on the prognosis of postoperative parotid gland carcinoma (PGC) remains unclear. This study investigates the role of GNRI in predicting disease-free survival (DFS) and overall survival (OS) in postoperative PGC patients and develops a predictive model. We conducted a retrospective analysis of 389 postoperative PGC patients treated from May 2008 to June 2019 at two regional medical centers in China. The independent prognostic factors were identified by univariate and multivariate Cox regression analyses. Then, two nomograms were established based on these independent prognostic factors and verified by a series of methods. The GNRI was identified as an independent prognostic factor in postoperative patients with PGC. A higher GNRI value indicated a worse prognosis for the patient. Based on the recognized independent prognostic factors—such as surgical margin, perineural invasion, extranodal extension (ENE), age-adjusted Charlson comorbidity index (ACCI), American Joint Committee on Cancer (AJCC) stage, and GNRI—two nomograms for overall survival (OS) and disease-free survival (DFS) were developed. The concordance index (C-index) for DFS was 0.712 and 0.730, while for OS it was 0.697 and 0.722 in the training and validation groups, respectively. These results demonstrate a significant improvement over the traditional AJCC staging system. Additionally, the area under the curve (AUC) values in both the training and validation sets were impressive, with all AUC scores exceeding 0.7. Decision curve analysis (DCA) also indicated substantial clinical benefits. The GNRI is an important predictive index in postoperative patients with PGC, which is not limited to the elderly. The newly developed nomograms provide a new tool of prognostic evaluations for postoperative patients with PGC.

The online version contains supplementary material available at 10.1038/s41598-025-08609-8.