Expression Of Ki-67,PCNA And MCM2 In Gastro Intestinal Stromal Tumors And Its Clinical Significance

Objective To investigate the expression of ki-67,PCNA and MCM2 protein in gastrointestinal stromal tumors (GISTs) and its relationship with the invasive risk level.Methods 26 GISTs were grouped into low-risk, intermediate-risk and high-risk. The expression of ki-67,PCNA and MCM2 protein were detected in 26 GIST and 10 normal tissues from the distal resection margin of colorectal cancer (control group) by immunohistochemical technique, and quantified ki-67,PCNA and MCM2 protein's expression by calculating a labeling index(L I).The L I of the three proteins in every group were compared, and an analysis of the association between the three proteins and the invasive risk level of GISTs was also carried out.Results (1) The L I of ki-67,PCNA and MCM2 in GISTs group were 15%(0%-70%),32.5%(0%～80%),30%(0%～90%) respectively, and they were 5%(0%～10%),17% (0%～25%),15%(0%～20%) respectively in control group. The differences between the two groups were statistical significance (P<0.01). (2) The L I of ki-67 were 5%(0%～10%),15%(0%～30%),35%(10%～70%) in low-risk, intermediate-risk and high-risk respectively. The L I of PCNA were 25%(5%～30%),24.5%(0%～40%),50%(15%～80%) in low-risk, intermediate-risk and high-risk respectively. The L I of MCM2 were 10.5%(1%～20%),20%(0%～40%),47.5%(10%～90%) in low-risk, intermediate-risk and high-risk respectively. The L I of ki-67 and MCM2 were compared respectively in low-risk, intermediate-risk and high-risk, and the differences were statistically significant (P<0.01).The statistical analysis showed that The L I of PCNA had significant difference between low-risk and high-risk, intermediate-risk and high-risk respectively (P<0.01).But there had no significant difference between low-risk and intermediate-risk (P>0.05). (3)The expression of ki-67,PCNA and MCM2 were associated with infiltration, metabasis and tumor diameter (P<0.05), but had nothing to do with patients'age, sex and initial occurring position (P>0.05). (4)Compared with the L I of ki-67, the LI of PCNA was higher and the difference was statistically significant (P<0.01).The L I of MCM2 was higher than ki-67, and the difference was statistical significance (P<0.01). The difference of the L I between PCNA and MCM2 was not significant (P>0.05).Conclusion:(1) The expression of ki-67 in GISTs was associated with the invasive risk level, and the L I was increased with the heightening danger classes. So ki-67 could be used for assessing the invasive risk level of GISTs. (2) The L I of PCNA in high-risk was obviously higher than that of low-risk or intermediate-risk.So it might be a useful marker to discriminate high-risk and low-risk/ intermediate-risk of GISTs.But it cannot be used for discriminate low-risk and intermediate-risk. (3)Compare with ki-67 and PCNA, MCM2 was better as proliferative marker.