The Expressions of E2F1 and p53 in Gastrointestinal Stromal Tumors and Their Prognostic Significance

ABSTRACT

BACKGROUND: E2F1 plays a critical role in the G1-to-S phase transition by inducing various genes that encode S phase-activating proteins and that modulate such diverse cellular functions as DNA synthesis, mitosis and apoptosis. The purpose of this study was to assess the E2F1 expression in relation to the clinicopathologic parameters and other tumor markers in gastrointestinal stromal tumors. METHODS: Immunohistochemical stainings for obtaining the E2F1, p53, and Ki-67 labeling indices were performed on a tissue microarray of 72 gastrointestinal stromal tumor specimens. The clinicopathologic parameters that were analyzed including the risk grade system by Miettinen et al. and the disease-free survival (DFS) rate. RESULTS: 1) An E2F1 expression was correlated with a larger tumor size, a p53 expression and a shorter period of DFS (p=0.014, p=0.007, and p=0.039). 2) A p53 expression was significantly associated with a high risk grade, a larger tumor size, high mitotic counts and a shorter period of DFS (p=0.003, p=0.044, p<0.001, and p<0.0001). 3) A high-risk grade and the epithelioid type were significantly associated with a shorter period of DFS (p=0.0006 and p=0.0008). CONCLUSIONS: E2F1, as well as p53, may be a potentially novel independent prognostic factor for predicting a worse outcome for those patients suffering with Gastrointestinal stromal tumors.