High MRE11 Expression Level Predicts Poor Survival in Upper Tract Urothelial Carcinomas

Upper tract urothelial carcinoma (UTUC) is an aggressive malignancy with characteristics of high metastasis and poor prognosis. There are some particularly different features of UTUC between the Asian and Western countries. Double-strand break repair protein MRE11 is a component of the MRN complex that is involved in the DNA repair pathway. Emerging studies have focused on the role of MRE11 in human malignancies with conflicting results. We aimed to establish the relationship between MRE11 expression and the oncological outcome of UTUC. This study retrospectively reviewed 150 patients who underwent radical nephroureterectomy with pathologically confirmed UTUC. Pathologic slides were reviewed, and clinical parameters were collected. An immunohistochemical study was performed, and the cytoplasmic and nuclear-staining results of UTUC were recorded. The expression of MRE11 was analyzed to identify correlations with various clinicopathological parameters, metastasis-free survival, and cancer-specific survival (CSS). MRE11 expression was significantly correlated with patients with a high pathologic stage (P=0.001), perineural invasion (P=0.015), and tumor necrosis (P=0.034). Upon univariate analysis, a high MRE11 expression was associated with poor metastasis-free survival (P=0.014, 95% CI 1.18, 4.38) and poor CSS (P=0.001, 95% CI 2.45, 27.75). Upon multivariable analysis, a high MRE11 expression was associated with poor CSS (P=0.019, 95% CI 1.28, 15.65). In summary, MRE11 expression could serve as a potential predictor of prognosis in patients with UTUC.