Gastrointestinal stromal tumors: a multivariate prognostic analysis

Objective To explore the biological behaviours of gastrointestinal stromal tumors(GISTs) and to analyze the multifactors in their prognoses.Methods Tissue microarray(TMA) technique was used in 194 cases diagnosed as GISTs to detect the expression of CD117,CD34,α-SMA,desmin,S-100,p53,Ki-67 and PCNA in the tissues by the immunohistochemical method of EnVision.The biological behaviors of the tumors were also analyzed by following-up the patients.Results Overall survival rates for 1 year,3 years and 5-years were 93.5%,72.1%,and 63.2% respectively.On single factor analysis,prognosis was related(P0.05) to primary location,tumor size,mitotic counts of the tumor cells,whether focal necrosis existed,cellularity of the tumor,type of tumor cells,nuclear atypia,hemorrhage,Ki-67 labeling index,p53 expression and gender etc.The prognosis of first treated patients was also relative to operational method,whether there was invasion of the surrounding organs and tissues and there was mucosa invasion or not.Multifactoral analysis showed that tumor size,mitotic counts,necrosis,direct invasion to the surrounding tissue and gender were very important factors which related to the prognoses.Conclusion There are considerable factors which influence the prognoses of GISTs.When the tumor diameter is over 10?cm,mitotic counts are ≥10 per 50 high power fields,along with necrosis and mucosal invasion all suggests higher possibilities of a maglinant nature.Ki-67 labeling index ≥5% and p53 positive expression are helpful to provide the prediction of its invasive behavior;In small intestinal stromal tumors,only that the tumors size is≥5?cm can sufficiently indicate that the tumor is easily recurrent and metastasizing.There is no relationship between the expression of CD34,SMA,desmin,PCNA,S-100 protein and its prognosis.