Prognostic nutritional index predicts severe complications, recurrence, and poor prognosis in patients with colorectal cancer undergoing primary tumor resection

BACKGROUND: The prognostic nutritional index is reportedly related to postoperative outcomes. OBJECTIVE: The aim of this study was to elucidate the clinical importance of the prognostic nutritional index in patients with colorectal cancer who were undergoing primary tumor resection. DESIGN: This is a retrospective study from a single institution. SETTINGS: This study was conducted at a colorectal surgery service in an academic teaching hospital. PATIENTS: The 556 patients with colorectal cancer who were undergoing surgery between March 2005 and August 2014 were eligible for this study. MAIN OUTCOME MEASURES: The preoperative prognostic nutritional index was calculated. Classification and regression tree analysis was performed to determine the prognostic nutritional index cutoff value. The associations of the prognostic nutritional index status with clinicopathological factors and postoperative outcomes were examined using univariate and multivariate analyses. RESULTS: Classification and regression tree analysis demonstrated that 45.5 was the optimal cutoff value. The low status (≤45.5) was correlated with older age, low BMI, low estimated glomerular filtration rate, CEA positivity, carbohydrate antigen 19-9 positivity, preoperative chemotherapy, tumors invading muscular or deeper layers, distant metastasis, poor differentiation, severe postoperative complications, tumor recurrence, and poor survival. In multivariate analysis, the low status was an independent risk factor for severe postoperative complications (OR = 2.06 [95% CI, 1.22-3.50]; p = 0.007) and low overall survival (HR =3.98 [95% CI, 2.38-6.89]; p < 0.001). LIMITATIONS: Our data set was collected retrospectively from a single institution. In addition, our study was only for preoperative prognostic nutritional index status, not considering the postoperative host status. CONCLUSIONS: The preoperative prognostic nutritional index predicts severe complications, recurrence, and poor prognosis in patients with colorectal cancer who are undergoing primary tumor resection. Investigation of the nutritional and immunologic statuses using the prognostic nutritional index could be a useful clinical approach.