Dynamic contrast-enhanced MRI predicts PTEN protein expression which can function as a prognostic measure of progression-free survival in NPC patients

Objectives The objective of our study was to investigate whether a phosphatase and tensin homolog deleted on chromosome 10 (PTEN) expression was associated with dynamic contrast-enhanced MRI (DCE-MRI) parameters and prognosis in nasopharyngeal carcinoma (NPC). Methods Two-hundred-and-forty-five (245) patients with NPC who underwent pretreatment biopsy, expression of PTEN detected by immunohistochemistry of biopsy, and radical intensity-modulated radiation therapy (IMRT) with or without chemotherapy were included. Tumor segmentations were delineated on pretreatment MRI manually. The pharmacokinetic parameters (K-trans, K-ep, V-e, and V-p) derived from dynamic contrast-enhanced MRI (DCE-MRI) using the extended Toft's model within the tumor segmentations were estimated. The following demographics and clinical features were assessed and correlated against each other: gender, age, TNM stage, clinical-stage, Epstein-Barr virus (EBV), pathological type, progression-free survival (PFS), and prognosis status. DCE parameter evaluation and clinical feature comparison between the PTEN positive and negative groups were performed and correlation between PTEN expression with the PFS and prognosis status using Cox regression for survival analysis were assessed. Results A significantly lower K-trans and K-ep were found in NPC tumors in PTEN negative patients than in PTEN positive patients. K-trans performed better than K-ep in detecting PTEN expression with the ROC AUC of 0.752. PTEN negative was associated with later TNM stage, later clinical-stage, shorter PFS, and worse prognosis. Moreover, N stage, pathological type, K-ep, and prognostic status can be considered as independent variables in discrimination of PTEN negative expression in NPCs. Conclusions PTEN negative indicated a shorter PFS and worse prognosis than PTEN positive in NPC patients. K-trans and K-ep derived from DCE-MRI, which yielded reliable capability, may be considered as potential imaging markers that are correlated with PTEN expression and could be used to predict PTEN expression noninvasively. Combined radiological and clinical features can improve the performance of the classification of PTEN expression.

Automated summary

In patients with nasopharyngeal carcinoma, PTEN negative status is associated with later TNM stage, later clinical-stage, shorter progression-free survival (PFS), and worse prognosis. K-trans and K-ep derived from DCE-MRI, with reliable capability, may serve as potential imaging markers correlated with PTEN expression for noninvasive prediction. Combining radiological and clinical features can enhance the classification performance of PTEN expression.