Murine double minute 2 and its association with chemoradioresistance of esophageal squamous cell carcinoma.

BACKGROUND: Definitive chemoradiotherapy (dCRT) has been established as the standard treatment for esophageal squamous cell carcinoma (ESCC). However, many patients develop persistent or recurrent disease following dCRT. We investigated factors related to chemoradioresistance and treatment outcomes in patients with ESCC who underwent salvage esophagectomy after dCRT. PATIENTS AND METHODS: We selected 38 patients with persistent disease and 24 with recurrent disease who underwent salvage esophagectomy after dCRT, immunolocalized p53, p16, p27, murine double minute 2 (MDM2), cyclin D1, Ki-67, and epidermal growth factor receptor, and correlated the findings with clinicopathological features. RESULTS: MDM2 positivity was significantly higher among patients with persistent disease than among those with recurrent disease (p<0.0001). In addition, negative p16 expression was a predictor of poor prognosis among patients with persistent disease. CONCLUSION: MDM2 overexpression plays an important role in chemoradioresistance of ESCC; furthermore, negative p16 expression can predict poor prognosis of patients with persistent disease.