The Expression Of Bcl-2 And Ki-67 Protein In Non-Hodgkin's Lymphoma And Their Role Of Autologous Hematopoietic Stem Cell Transplantation For Malignant Lymphoma

Background: The main reason of malignant lymphoma(ML) was cell apoptosis inhibition and cell proliferative acceleration. Therefore,the examination of factors related with apoptosis and proliferation could aid the prognosis evaluation. Bcl-2 was a famous apoptosis-antagonizing protein; Ki-67 was an important proliferative antigen.Objective: 1. To evaluate the expression of Bcl-2 and Ki-67 in non-Hodgkin's lymphoma (NHL). 2. To study the role of Bcl-2 and Ki-67 in autologous hematopoietic stem cell transplantation (AHSCT) for malignant lymphoma (ML).Methods: 1. Bcl-2 protein and Ki-67 antigen were measured by immunohistochemistry (IHC) on paraffin-embedded slices in 61 cases of NHL and in 30 cases of ML who received AHSCT. 2. Survival analysis was done by the Kaplan-Meier method and log-rank test. Multivariate analysis was carried out using Cox proportional hazard model.Results: 1. The positive rate of Bcl-2 expression in B cell NHL was higher than that in T cell NHL (P<0.05), but there was no difference in the expression of Ki-67 between two types of NHL. 2. For B cell NHL, the 3-year survival rate for patients with Bcl-2(+) and Bcl-2(-) were 22.22% and 55.56%, respectively (P<0.05). But for T cell NHL, there was no significant difference of survival time between the positive and negative Bcl-2 group ( 3-year survival time: 42.86% vs 61.54% , P>0.05). 3.The3-year survival rate for NHL patients with Ki-67(+) and Ki-67(-) were 37.50% and 53.33%, respectively (P>0.05). 4. For B cell NHL, the 3-year survival rates for patients with both positive Bcl-2 and Ki-67 and both negative were 16.67% and 66.67%, respectively(P<0.01). 5. For patients with ML who received AHSCT, the 3-year disease free survival (DFS) of Bcl-2(+) group was 35.71% , while that Bcl-2(-) group was 88.89%. There was significant difference of DFS between the two groups. Meanwhile, for these patients, the 3-year DFS of Ki-67(+) and Ki-67(-) were 43.75% and 85.71%, respectively (P<0.05). 6. Multivariate analysis showed that the expression of Ki-67 antigen was the only independent prognostic factor.Conclusion: 1. There was direct relationship between Bcl-2 protein expression and the prognosis in B cell NHL. Combined examination of Bcl-2 and Ki-67 can be utilized to predict the prognosis of patients with B cell NHL 2. The expression of Bcl-2 and Ki-67 were closely related with relapse after AHSCT in patients with ML. They were useful molecular makers for predicting the prognosis of patients with ML after AHSCT.