Expression Of Tumor Suppressor Genes Rb,p16 And Prognosis Of Gastric Carcinoma

Objective: To study the relationship between the expression of tumor-supressor genesRb,p16 and prognosis of gastric carcinoma. Methods: Expression of tumor-suppressorgenes Rb and p16 was examined by immunohistochemical method of ElivisiontTM plus inparaffin slice from 30 resectional gastic carcinoma tissue and 20 normal gastric tissue.Results: 1.The positive rate of Rb and p16 were 73.33% and 53.33% respectively ingastric carcinoma tissue and both 100% in normal gastric tissue (P=0.015 and P=0.0003).2.In 30 cases of gastric carcinoma, 9 cases have no lymphatic metastasis and theexpression of Rb were positive; 21 cases have lymphatic metastasis and among them 12cases the expression of Rb were positive, the positive rate was 57.1% , P=0.029. In 14cases with carcinoma mass diameter <5 cm and 16 cases with carcinoma mass diameter≥5 cm, the positive rate of Rb was 92.9% and 56.3% respectively, P=0.04. 3.In 19 casesof the depth of inflilatration was T1+T2 and 16 cases of the depth of inflilatration wasT3+T4, the positive expression of p16 were 73.3% and 18.2% respectively, P=0.007.The positive expression of p16 were 8/9 (88.9%) cases in the cases of no lymphaticmetastasis and 8/21(38.1%) cases in the cases of lymphatic metastasis, respectively,P=0.017. The positive rate of p16 in the clinical stageⅠ+Ⅱand Ⅲ+Ⅳwere 77.8%and 16.7% respectively, P=0.002. 4.In gastric carcinoma tissue, the rank correlationcoefficient of the expression of Rb and p16 was -0.3994. 5. The survival curve in thepositive cases of Rb expression was higher than that in the negative, log-rank test showedthat x2=12.099,P<0.05; the survival curve in the positive cases of p16 expression wasalso higher than that in the negative, x2=6.677, P<0.05. 6.Compared with the group thatboth expression of Rb and p16 were negative, the group that both expression werepositive had higher survival curve, x2=17.267,P<0.05;and the case fatality of the twogroups that both positive and both negtive were 8.3%and 100% respectively, P=0.0027.Compared with the group that only one of the expression of Rb and p16 was positive, thegroup that both expression were positive had higher survival curve too, x2=7.505,P<0.05;and the case fatality of the two groups that both positive and only one positivewere 8.3% and 64.3% respectively, P=0.0052. Conclusion: 1.Both the expression of Rband p16 existed deletion in gastic carcinoma tissue. 2.There was significant correlativitybetween the expression of Rb and the size of the gastric carcinoma and lymphaticmetastasis. The expression of Rb was significantly relative to the depth of gastriccarcinoma inflilatration, lymphatic metastasis and clinical stages. 3.In gastric carcinomatissue, the expression of Rb was significantly negatively relative to the expression of p16.4.The survival rate in the cases of Rb and p16 positive expression were siginificantlyhigher than that in the negative cases. 5.Compared with the two groups that bothexpression of Rb and p16 were negative and only one of that was positive, the group thatboth expression were positive had significantly higher survival rate and lower casefatality. 6.Either Rb or p16 possesses prognostic value in gastric cancer, howevercombinating the two would be more valuable than either of one alone.