Δ133p53/FLp53 Predicts Poor Clinical Outcome in Esophageal Squamous Cell Carcinoma

Background: p53 isoform Delta 133p53 is directly transactivated by p53 and antagonizes p53 activities in cancer progression. However, its correlation with prognosis and cancer recurrence in esophageal squamous cell carcinoma (ESCC) is still unclear. Patients and Methods: Expression of Delta 133p53 and Delta 133p53/full-length p53 (FLp53) in tissues and serums of 180 ESCC patients was evaluated using qRT-PCR. Patients were divided into high- and low-expression groups according to the cutoff value determined by X-tile 3.6.1 software. Survival analysis was performed by the Kaplan-Meier method. Univariate and multivariate Cox survival analyses were applied to assess the hazard ratios (HRs). Results: Tissue Delta 133p53 expression and Delta 133p53/FLp53 ratio were significantly increased in ESCC tissue compared with adjacent normal tissue. Pre-operative Delta 133p53 expression and Delta 133p53/FLp53 ratio in tissue or serum samples were positively associated with TNM stage and post-operative recurrence. Kaplan-Meier curve and multivariate cox regression analyses revealed that the tissue and serum Delta 133p53/FLp53 ratios (cutoff value: 2.9160) were independent prognostic factors for overall survival (OS) and progression-free survival (PFS) in ESCC patients and showed no statistical difference in receiver-operating characteristic curve (ROC) analysis, while serum Delta 133p53 showed no significant prognostic value. More importantly, the serum Delta 133p53/FLp53 ratio in ESCC patients was significantly decreased within 72 h post tumor resection and patients with a consistently high serum Delta 133p53/FLp53 ratio (=2.9160) had higher recurrence rates than those with consistently low ratio values. In addition, dynamic detection in each follow-up timepoint showed that serum Delta 133p53/FLp53 ratios were higher than 2.9160 upon recurrence, and they even increased prior to radiologic progression. Conclusion: The serum Delta 133p53/FLp53 ratio can be a novel predictor for survival outcome and may serve as a real-time parameter for monitoring recurrence in ESCC patients after surgery.