Prognostic significance of baseline nutritional index for patients with esophageal squamous cell carcinoma after radical esophagectomy

Background Radical esophagectomy is the cornerstone of curative treatment for patients with resectable esophageal squamous cell carcinoma (ESCC). Patient survival after surgery for ESCC is mainly associated with pathological tumor progression. Recently, the impact of baseline immune-nutritional status of various types of patients with cancer on survival has been highlighted. The purpose of the present study was to investigate the association between the baseline prognostic nutritional index (PNI) and postoperative short-and long-term results after esophagectomy for patients with ESCC. Methods In total, 202 patients with ESCC who underwent radical esophagectomy at our institution between 2002 and 2010 were enrolled. PNI was calculated as 10x serum albumin (g/dL) + 0.005 x total lymphocyte counts (per mm3). Receiver operating characteristic (ROC) curves were generated for multiple logistic regression analysis using 5-year overall survival as the endpoint to determine an optimal PNI cutoff value, in which patients were classified into two groups: high PNI and low PNI. We evaluated the significance of PNI on postoperative morbidity and long-term survival using univariate and multivariate analyses. Results The mean PNI was 48.9 +/- 4.6 (range 37.2-64.0). The area under the ROC curve in multiple logistic regression analysis was 0.5367. The projected 5-year survival rate was optimal at a PNI of 44.1. Hence, the PNI cutoff point was set at 44, with subjects classified by PNI level into the low (PNI < 44) or high (PNI = 44) PNI groups. Of 202 patients, 173 (85.7 %) and 29 (14.3 %) were classified as having high and low PNI, respectively. No significant differences were noted between the two groups regarding patient background, including age, sex, pT, pN, and pStage, or postoperative complications. However, overall survival (OS) and relapse-free survival (RFS) were significantly worse in the low PNI group than in the high PNI group. The 5-year OS and RFS rates in the high PNI vs. low PNI groups were 67.2 vs. 41.2 % (P = 0.007) and 61.5 vs. 38.8 % (P = 0.008), respectively. Multivariate analysis revealed that PNI was a significant prognostic factor for both OS (hazard ratio, 1.826; 95 % confidence interval, 1.015-3.285; P = 0.044) and RFS (hazard ratio, 1.862; 95 % confidence interval, 1.121-3.095; P = 0.016). Conclusion Preoperative PNI is an independent prognostic marker of both OS and RFS for patients with potentially curative ESCC. A careful follow-up for tumor recurrence after surgery is required for ESCC patients with low PNI.