Significance of Onodera’s prognostic nutritional index in patients with colorectal cancer: a large cohort study in a single Chinese institution

The preoperative nutritional and immunological statuses have an important impact in predicting the survival outcome of patients with various types of malignant tumors. Our study aimed to explore the clinical significance and predictive prognostic potential of Onodera’s prognostic nutritional index (PNI) in patients with colorectal carcinoma. This retrospective study included a total of 1321 patients who were diagnosed with colorectal cancer and who had been surgically treated between January 1994 and December 2007. The PNI level was determined according the following formula: 10 × serum albumin (g/dL) + 0.005 × total lymphocyte count (per mm³). The impact of PNI on clinicopathological features and overall survival (OS) was determined. The optimal cutoff value of PNI was set at 45. Patients in the low-PNI group had a greater potential to have aggressive histological features, advanced tumors (T), nodal involvement (N), metastasis (M), and TNM stage than those in the high-PNI group. The low-PNI group had a worse OS than the high-PNI group (5-year survival rate 56.1 vs 64.8 %, respectively; P < 0.05). Furthermore, the PNI value was an independent prognostic factor for colorectal cancer in this study. The OS was significantly lower in the low-PNI group than in the high-PNI group in patients with TNM stage II and III diseases. Preoperative PNI is a simple and useful marker to predict clinicopathological features and long-term survival outcome in patients with colorectal carcinoma. PNI analysis should be included in the routine assessment of patients with locally advanced colorectal cancer.