Prognostic significance of body mass index and prognostic nutritional index in stage II/III gastric cancer

Introduction Preoperative body weight and nutritional status are related to prognosis in patients with gastric cancer; however, the prognostic impact of postoperative in these variables is unclear. We aimed to investigate the association of preoperative/postoperative body mass index (BMI) and prognostic nutritional index (PNI) with prognosis in patients with gastric cancer. Materials and methods We retrospectively 1868 patients with stage II/III gastric cancer treated with gastrectomy between January 2006 and December 2010. We divided the populations into 3 groups according to BMI; underweight, normal, and overweight. Patients were divided into 3 groups according to BMI (underweight, normal-weight, overweight). PNI was classified into low and high (cutoff value; 49.7). The association of preoperative BMI/PNI and their changes (6 months postoperatively) with clinicopathologic characteristics were evaluated. Results Preoperative underweight and low PNI were related to poor prognosis (log-rank p < 0.001 for both). There was a positive correlation between preoperative BMI and PNI (mean preoperative PNI: 51.13 [underweight], 53.37 [normal-weight], and 55.16 [overweight]; p < 0.001). Preoperative BMI and PNI were independent prognostic factors for disease-free survival along with age and TNM stage (p < 0.001 for both). BMI changes from normal-weight to underweight and from overweight to normal/underweight were related to poor prognosis (log-rank p = 0.021 and p = 0.013, respectively). PNI changes were related to prognosis in both the preoperative low and high PNI groups (p < 0.001 and p = 0.019, respectively). Conclusion Preoperative BMI and PNI and their postoperative changes are related to prognosis in patients with stage II/III gastric cancer. Careful nutritional intervention after gastrectomy can improve prognosis.