Prognostic Value of a Novel Index Combining the Prognostic Nutritional Index and D-Dimer Levels for Gastric Cancer after Gastrectomy

Introduction: The prognostic nutritional index (PNI) and D-dimer level are two useful measures for gastric cancer prognosis. As they each comprise different factors, it is possible to employ a more useful combined indicator. This study therefore aimed to establish a PNI-D score - which combines the PNI and D-dimer level - and validate its usefulness as a prognostic marker.

Methods: We collected data from 1,218 patients with gastric cancer who had undergone radical gastrectomy (R0) between January 2004 and December 2015. Patients were divided into three PNI-D score groups based on the following criteria: score 2, low-PNI (≤46) and high D-dimer levels (>1.0 µg/mL); score 1, either low-PNI or high D-dimer levels; and score 0, no abnormality. We defined the PNI-D score as low (score 0 or 1) and high (score 2), respectively.

Results: The PNI-D score was significantly associated with overall, recurrence-free, and disease-specific survival (all log-rank p < 0.0001). The 5-year overall survival rates of patients with PNI-D scores of low and high were 88.1% and 64.7%, respectively; their 5-year recurrence-free survival rates were 86.7% and 61.3%, respectively; and their 5-year disease-specific survival rates were 99.3% and 76.5%, respectively. Cox multivariate analysis revealed that a high-PNI-D score was an independent, statistically significant prognostic factor for poor overall (p = 0.01) survival in patients with gastric cancer.

Conclusions: The PNI-D is an independent prognostic factor for patients with gastric cancer.