Prognostic nutritional index predicts lateral lymph node metastasis and recurrence free survival in papillary thyroid carcinoma.

BACKGROUND

Preoperative hematological parameters are predictors of pathological features and recurrence-free survival (RFS) in various malignancies. However, comprehensive studies of preoperative indicators associated with papillary thyroid carcinoma (PTC) are scarce. The present study investigated the association between preoperative indicators and RFS in patients with PTC. Accordingly, we explored the clinical impact of the prognostic nutritional index (PNI) on lymph node metastasis and RFS in patients with PTC.

METHODS

A total of 619 PTC patients were retrospectively reviewed between Jan 2013 and Dec 2017. Laboratory values were measured and calculated. Receiver operating characteristic curves were generated to calculate the cutoff value. Univariate and multivariate analyses using the COX proportional hazard model were performed for RFS. The effects of PNI and age on RFS were investigated by the Kaplan-Meier method. Clinical characteristics and PNI were tested with the chi-square test. Univariate and multivariate logistic analyses were conducted to evaluate the predictive value of PNI for lymph node metastasis.

RESULTS

In the multivariate Cox analysis, age, PNI and lymph node metastasis were independent prognostic indicators for RFS. The Kaplan-Meier method showed that the lower PNI group and age older than 55 years group displayed poor RFS. A low preoperative PNI was remarkably correlated with age, sex, extrathyroidal invasion, T stage, N stage and TNM stage. PNI was the only preoperative hematological indicator for lateral lymph node metastasis.

CONCLUSIONS

Among the preoperative hematological indicators, PNI may serve as a promising and effective predictor for RFS and lateral lymph node metastasis in PTC patients.