Background/objective: To investigate the impact of preoperative immunological and nutritional status, using the prognostic nutritional index (PNI), on completion of planned adjuvant chemotherapy (AC), and the potential additive effects of low PNI and incomplete AC on gastric cancer-specific survival (CSS) after curative resection of stage II/III gastric cancer (GC).
Methods: Medical records of 1288 consecutive stage II/III GC patients who underwent curative resection and planned to receive AC between November 2010 and December 2017 were retrospectively reviewed. The optimal cut-off value of PNI for CSS was determined by X-tile. The independent predictive factors for incomplete AC were identified using univariate and multivariate analyses. Cox regression analyses assessed the association of low PNI, incomplete AC and CSS.
Results: Of the 1288 patients, 406 (31.5%) completed at least six cycles of AC within 6 months following initial of AC (complete AC). Low PNI (<43.9, n = 386) was identified to be an independent risk factor for incomplete AC (<6 cycles). Both low PNI and incomplete AC independently predicted poor CSS (hazard ratio (HR): 1.287, 95% confidence interval (CI): 1.058-1.565; HR: 1.667, 95% CI: 1.342-2.071). Further analyses confirmed an additive effect with those with both low PNI and incomplete AC having an even worse CSS.
Conclusions: Low preoperative PNI significantly affects completion of AC. Low PNI and incomplete AC has an additive effect and is associated with even worse outcomes. Further prospective studies are needed to clarify whether perioperative nutrition intervention could improve completion of AC and improve prognosis of GC patients.