Prognostic Value Of CD47 Expression In Different Subtypes Of DLBCL

PurposeDiffuse large B-cell lymphoma(DLBCL)is a group of highly heterogeneous hematologic malignancies.The current first-line treatment regimen is rituximab combined with cyclophosphamide,doxorubicin,vincristine and prednisone.This regimen can cure approximately 60%of DLBCL patients,but the remaining refractory or recurrent patients will face a very poor prognosis.In order to improve the survival of these patients,it is extremely important to understand the underlying mechanism of drug resistance.Rituximab is thought to work by inducing an antibody-dependent cellular phagocytosis that may be inhibited in drug-resistant patients by CD47 expressed on the surface of tumor cells.A previous small sample study of our group found that CD47 expression was correlated with the prognosis of DLBCL.Meanwhile,CD47 monoclonal antibody could enhance the phagocytosis of macrophages to tumor cells through in vitro experiments.Therefore,by expanding the sample size and extending the follow-up time,this study-further explored the expression of CD47 molecule in DLBCL and its relationship with prognosis,so as to provide data reference for the clinical application of CD47 monoclonal antibody in the future.MethodIn this study,108 patients with diffuse large B cell lymphoma diagnosed by pathology were retrospectively analyzed,and clinical and survival information was obtained by electronic medical record system and telephone follow-up.The expression of CD47 in pathological tissues was obtained by immunohistochemical method.The relationship between CD47 expression and clinical characteristics and between CD47 and progression-free survival and overall survival were analyzed statistically.Result1.There were 58 patients with low expression of CD47,the 5-year progression-free survival rate was 76.3%,and the 5-year overall survival rate was 78.1%.The 5-year progression-free survival rate and 5-year overall survival rate for patients with middle expression of CD47(n=28)were 65.5%and 64.5%respectively.The 5-year progression-free survival rate was 42.9%and the 5-year overall survival rate was 53.2%in 22 patients with high expression.The overall difference was statistically significant(P=0.004 for PFS,P=0.001 for OS).2.Multivariate survival analysis showed that CD47 score,independent of gender and IPI score,was an independent prognostic factor for progression-free survival(HR=1.676,P=0.009)and also an independent prognostic factor for overall survival(HR=1.953,P=0.001).3.In patients with positive MYC expression,the proportion of CD47 middle or high expression was 20/26.In patients with negative MYC expression,the proportion of CD47 middle or high expression was 18/35.The difference was statistically significant(P=0.042).4.In patients with bone marrow involvement,the proportion of CD47 middle or high expression was 14/16;In patients without bone marrow involvement,the proportion of CD47 middle or high expression was 35/90.The difference was statistically significant(P<0.001).Conclusion1.The expression level of CD47 is related to MYC expression level and is related to bone marrow involvement.2.The expression level of CD47,independent of IPI score,is an independent prognostic factor for progression-free survival and overall survival.