Expression and clinical significance of STIP1 in papillary thyroid carcinoma

The aim of this study was to detect stress-induced phosphoprotein 1 (STIP1) expression in papillary thyroid carcinoma (PTC) and to analyze its association with prognosis of PTC patients. Immunohistochemistry was performed to detect the expression of STIP1 in 113 PTC tissues and paired adjacent noncancerous tissues. The χ2 test was used to analyze the relationship between STIP1 expression and clinicopathological characteristics. Survival curves were plotted by the Kaplan-Meier method and compared using the log-rank test. Survival data was evaluated using univariate and multivariate Cox regression analysis. We identified abnormally elevated expression of STIP1 protein in PTC tissues compared to paired adjacent noncancerous tissues. Clinicopathological analysis showed that STIP1 expression was significantly correlated with tumor size (P = 0.017), lymph node metastasis (P = 0.007), and TNM stage (P = 0.026). Patients with higher STIP1 expression had shorter overall survival time, whereas those with lower STIP1 expression had longer survival time. Multivariate analysis suggested that STIP1 expression might be an independent prognostic indicator (P < 0.05) for the survival of patients with PTC. In conclusion, our findings provide evidences that positive expression of STIP1 in PTC may be important in the acquisition of an aggressive phenotype, and it is an independent biomarker for poor prognosis of patients with PTC.