Effect of Onodera′s prognostic nutritional index on the prognosis of esophageal squamous cell carcinoma after intensity-modulated radiotherapy / 中华放射肿瘤学杂志

ABSTRACT

Objective:To investigate the relationship between Onodera′s prognostic nutritional index (PNI) and prognosis of patients with esophageal squamous cell carcinoma (ESCC) after definitive chemoradiotherapy or radiotherapy, aiming to provide a convenient, effective and accurate predictive indicator for evaluating the long-term survival of patients after treatment.Methods:Clinical data of 231 ESCC patients treated with definitive chemoradiotherapy or radiotherapy at the Fourth Hospital of Hebei Medical University from 2013 to 2015 were retrospectively analyzed. The PNI values of each patient at different radiotherapy periods were calculated and the ROC curve was used to determine the optimal cutoff value of PNI before radiotherapy, 231 patients were divided into the better-nourishment group ( n=86) and worse-nourishment group ( n=145). Kaplan- Meier method was used for survival analysis. Cox proportional hazards model was utilized to analyze the relationship between different nutritional status and prognosis. The short-term clinical efficacy and incidence of acute toxicities were statistically compared between two groups. Results:The mean values of PNI before, at week 3, week 6 and 1 month after radiotherapy were48.68±5.08, 39.68±4.87, 43.74±4.89 and48.31±4.92, respectively. The optimal cutoff value of pretreatment PNI was 49.25, the area under the curve (AUC) was 0.655, the sensitivity and specificity were 68.6% and 60.9%, respectively. The 5-year overall survival (OS) and progression-free survival (PFS) rates in the better-nourishment group (PNI≥49.25) were 36.0% and 31.3%, significantly better than 19.3% and 18.6% in the worse-nourishment group (PNI<49.25)( P=0.001, P=0.039). Multivariate analysis showed PNI before the therapy was an independent prognostic factor for OS ( P=0.021). Stratified analysis demonstrated that Stage Ⅰ/Ⅱ and concurrent chemotherapy patients in the better-nourishment group all obtained significantly better OS than their counterparts in the worse-nourishment group ( P=0.007, P=0.004). In addition, the objective response rate in the better-nourishment group was significantly higher than that in the worse-nourishment group ( P=0.047), whereas the incidence of ≥3 grade radiation esophagitis was lower than that in the worse-nourishment group ( P=0.060). Conclusions:Pretreatment PNI is a convenient and reliable indicator for predicting the long-term survival of ESCC patients after definitive chemoradiotherapy or radiotherapy. Patients with higher PNI have relatively better prognosis and radiotherapy tolerance, especially in those with early stage or concurrent chemotherapy.