Clinical Impact of the Prognostic Nutritional Index as a Predictor of Outcomes in Patients with Stage II/III Gastric Cancer: A Retrospective Cohort Study

Background: The Japanese Gastric Cancer Treatment Guidelines recommend S-1 and S-1 plus docetaxel as postoperative chemotherapy for pathological stage II and III gastric cancer (GC). There is currently no strategy for using chemotherapy to treat high-risk recurrent pathological stage II/III. Previous studies reported that the several nutritional, immunological, and inflammatory markers examined the association with clinical outcomes after surgery for GC. Methods: Ninety patients with GC (stage II, n = 48; stage III, n = 42) for whom gastrectomy was performed at our institution between November 2009 and September 2018 were examined. Nutritional, immunological, and inflammatory markers were calculated from blood samples within 1 week before surgery. Results: The prognostic nutritional index (PNI) status correlated with the pathological stage and disease recurrence after surgery (p = 0.015 and p < 0.0001, respectively). Thirty-three patients had disease recurrence after gastrectomy (stage II, n = 11; stage III, n = 22). The PNI was significantly lower in the recurrent group than in the non-recurrent group (p = 0.0003). The PNI correlated with overall survival and recurrence-free survival after gastrectomy (p = 0.0021 and p = 0.0001, respectively). A multivariate analysis identified the PNI as an independent prognostic factor (p = 0.006). Conclusion: The PNI may be useful for predicting the outcomes of patients with pathological stage II/III GC and may contribute to the selection of an appropriate adjuvant chemotherapy regimen.