Clinicopathological Characteristics And Prognosis Of Primary Bone Diffuse Large B-Cell Lymphoma

Purpose:The purpose of this study is to assess the clinicopathological features and explore the prognostic factors of primary bone diffuse large B-cell lymphoma(PB-DLBCL),to analyze the similarities and differences between PB-DLBCL and systemic DLBCL with bone involvementMaterial and Methods:We collected 22 cases of PB-DLBCL and 28 cases of systematic DLBCL with bone involvement who were pathologically confirmed in the department of hematology of the second affiliated hospital of Zhejiang university school of medicine from January 2013 to January 2018.We compared differences of clinicopathological features between PB-DLBCL and systematic DLBCL with bone involvement and explored the prognostic factors of PB-DLBCL.With SPSS20.0,unpaired t test,Chi-square test,Kaplan-Meier and Cox regression risk model were used for statistical analysis.Results:Among the 22 newly diagnosed PB-DLBCL and 28 newly diagnosed systematic DLBCL with bone involvement,the median age of diagnosis was 59.6 years and 56.8 years,respectively.And the male-to-female ratio was 1.75 and 1.80.Compared with systematic DLBCL with bone involvement,PB-DLBCL patients were more likely to present with obvious bone pain(81.8%vs.50.0%,P=0.020)and soft tissue mass(80.0%vs.52.6%,P=0.034),and less likely to present with high lactic dehydrogenase(LDH)(27.3%vs.64.3%,P?0.009),high ?2 microglobulin(?2-MG)(22.2%vs.50.0%,P?0.047)and IPI?2(45.5%vs.80.8%,P?0.011).However,there were no great difference in age,sex,B symptom,performance status,calcium level,alkaline phosphatase level,virus infection,pathological subgroup,Ki67%,BCL2 expression,MYC expression,imaging of bone destruction or standardized uptake value between two groups.The median follow-up time is 25(1-72)months.21 PB-DLBCL and 26 DLBCL with bone involvement patients received therapies.The 1,2 year survival rates of two groups were 95.2%and 73.1%,81.0%and 65.4%respectively.The differences of overall survival(P?0.476)or progress free survival(P?0.330)were no statistical significance between two groups.Univariate analysis found that BCL<30%significantly prolonged PFS for PB-DLBCL patients.Conclusions:PB-DLBCL is more common in middle-aged and elderly males.Bone pain is main clinical manifestation.The major pathological subtype is non-GCB and major lytic lesions are long bones,pelvis and spine.Local bone pain,serum level of LDH and?2-MG,soft tissues around the bone lesions and IPI are helpful in identifying PB-DLBCL and DLBCL with bone involvement.BCL2 expression less than 30%prolongs PFS of PB-DLBCL patients.