The Expression And Significance Of PKC-θ And P16/INK4α In GIST

Objective To investigate the clinicopathologic features of GIST.To investigate the correlations among clinical diagnosis,treatment, prognosis and the expression of PKC-θand p16/INK4αin GIST.Methods (1)Cutting sections and HE staining were carried out in 87 GIST and the clinicopathologic dates were reviewed.The all cases were divided into four groups according to Fletcher's scheme.And CD117,SMA ,CD34 and S-100 were examined in every group by immunohistochemical method.(2) PKC-θand CD117 immunohistochemistry was carried out not only in 87 cases of GIST and 2 cases of leiomyoma,2 cases of leiomyosarcoma,5 cases of schwannoma,6 cases of malignant schwannoma ,3 cases of thymic carcinoma,and 5 cases of seminoma,renal chromophobe cell,malignant melanoma.(3) p16/INK4αimmunohistochemistry was carried out in 67 GISTs with following-up dates.Results (1)87 cases in this study were divided into 4 groups,including subclassification of very low risk of aggressive behavior(Ⅰ,17 cases),of low risk(Ⅱ,23 cases),of intermediate risk(Ⅲ,cases) and of high risk(Ⅳ,24 cases).χ2 test of 62 cases whom had been followed up for 18 to 123 months showed a statistically significant difference present betweenⅣandⅢ(P<0.005),ⅣandⅠandⅡ(P<0.005),but there was no significant difference present betweenⅢandⅠandⅡ(P>0.05).There are some following additional factors in some tumors:coagulative,nuclear atypia,bleeding,calcification.CD117 expression was detected in 71(81.6%),CD34 in 62(71.3%).There was no predictive value for CD117 expression in 4 subclassification of GIST.(2) Among 87 GISTs,77 cases(88.5%) were positive for PKC-θand 71 cases(81.6%) for CD117.There were 12 PKC-θexpression GISTs in 16 CD117 negative expression.And percentage of epithelioid tumors expressed PKC-θ(9/11).There were 83 cases(95.5%) of GIST expressed CD117 and/or PKC-θ,and there were 4 GISTs immunohistechemically negative for CD117 and PKC-θ.χ2 test showed the expressions of PKC-θhad no correlation with expression of CD117(χ2=1.389,P>0.05),but correlated with subclassification of GISTs using Fletcher's scheme and PD.In another 15 cases of gastrointestinal mesenchymal tumors and 18 cases of various tumors, CD117 expression in six type of tumors except schwannoma and...