Association among prognostic nutritional index, post-operative infection and prognosis of stage II/III gastric cancer patients following radical gastrectomy

Background/objective To investigate the influence of pre-operative immunological and nutritional status, assessed by the prognostic nutritional index (PNI) score, on post-operative infection, and the potential additive effects of low PNI and infection on prognosis after radical resection of stage II/III gastric cancer (GC). Methods The medical records of 2352 consecutive stage II/III GC patients who underwent radical gastrectomy were retrospectively reviewed. The independent predictors for infections were identified using univariate and multivariate analyses. Cox regression analysis was used to assess any associations between PNI, infection and OS. Results A total of 160 (6.8%) cases developed infections and low PNI (< 43.9) was confirmed as an independent predictor. Both PNI < 43.9 and infections independently predicted poor OS (hazard ratio: 1.163, 95% confidence interval: 1.007–1.343; HR: 1.347, 95%CI: 1.067–1.700), and an additive effect was confirmed as patients with both low PNI and infection had worst OS. Further stratified analyses showed that complete peri-operative adjuvant chemotherapy (PAC, ≥ 6 cycles) could significantly improve OS in patients with low PNI and/or infection, which was comparable to those with PNI ≥ 43.9 and/or infection ( P = 0.160). Conclusions Infection was the most common complication after gastrectomy and PNI < 43.9 was identified as an independent predictor. Low PNI was associated with poorer OS in stage II/III GC, independent of infections, and low PNI and infections had a synergistic effect that was associated with worst OS. However, complete PAC could significantly improve OS in these patients. Thus, strategies to decrease infection and complete PAC should be further investigated.