Brain metastasis has become a major failure pattern with the prolonged survival of patients with non-small cell lung cancer (NSCLC). Prophylactic cranial irradiation (PCI) has been proven to play a significant role in small cell lung cancer, whereas its value in NSCLC is still controversial. Therefore, this article reviewed the role of PCI in NSCLC, high-risk factors of brain metastasis, timing, dose fraction and toxicity of PCI, etc.

Objective To investigate the expression of p53,p27 and mdm2 protein in gastrointestinal stromal tumor(GIST),and discuss the relationship between their expression and clincopathological characteristics.Methods Immunohistochemical staining was used to detect the expression of p53,p27 and mdm2 in 68 cases of GIST.Their relations with histo-morphology and biological behavior were analyzed statistically.Results In 68 cases GIST,the positivity of p53,p27 and mdm2 protein were 75%,54.41% and 27.94% respectively.The expression of p53 protein was inversely correlated with the fletcher degree,morphologic variant(P0.05) and tumor diameter(P0.01) of GIST.The expression of p27 protein was inversely correlated with the fletcher degree(P0.05) and tumor diameter of GIST(P0.01).The expression of mdm2 protein was inversely correlated with the morphologic variant(P0.01) of GIST.Conclusion These data shows the expression of p53,p27 and mdm2 are related to the ontogenesis and progression of GIST.p53,p27 and mdm2 may be prognostic indicators in GIST.