[Clinical characteristics of 46 pediatric diffuse large B-cell lymphoma and treatment outcome]

Objective: To summarize the clinical data of diffuse large B-cell lymphoma (DLBCL) in children and to evaluate the efficacy of Beijing Children's Hospital B cell lymphoma protocol in the treatment of pediatric DLBCL. Methods: The data (clinical, pathology, lab and image data) of 46 pediatric DLBCL admitted to the treatment group of Beijing Children's Hospital from January 2005 to June 2017 were collected and analyzed retrospectively. According to the risk factors of staging, existence of poor prognosis genes and giant tumors, stratified treatment was carried out according to the international standard modified LMB89 regimen with high dose and short course. The Kaplan-Meier method was used to calculate the event free survival (EFS) and the overall survival (OS). Results: (1) Among the 46 cases, there were 33 males and 13 females. The median age was 8.0 years. The time from the initial symptom onset to the diagnosis was more than 15 days in 45 children. Fourteen cases had B group symptoms (fever, night sweat, and weight lost), 25 cases had extranodal disease, 39 cases were stage Ⅲ and Ⅳ, 12 cases had bone marrow involvement, 3 cases had jawbone involvement. Thirty cases were group B and 16 cases were group C in the treatment group. (2) Initial symptoms: 6 cases had cervical mass, 20 cases had abdominal mass, 10 had abdominal pain with acute abdomen, 8 cases had fever, 2 cases had snore or upper respiratory tract obstruction. (3) Pathology result: 40 cases were germinal center B cell DLBCL, 6 cases were non germinal center B cell DLBCL, no case had the MYC gene rupture, double hit lymphoma and triple hit lymphoma. (4) Complication and evaluation: the tumor lysis syndrome was seen in 3 cases initially, severe infection and delayed treatment was seen in 1 case, no treatment related death. The first evaluation showed all cases were sensitive to chemotherapy (shrink>25%), the second evaluation showed 1 case had residual disease, the others were complete remission. (5) Treatment and outcome: the 5 year-EFS was the same with 5 year-OS, both were (97.8±2.2) %. Two cases relapsed after treatment off, early relapse was seen in 1 case, and died because of abandoning treatment. Late relapse was seen in 1 case and got a complete remission after Rituximab+group C protocol treatment. Conclusions: Pediatric DLBCL was common in school aged boys, most cases were at middle and late stage at the time of diagnosis. DLBCL had a good prognosis after the treatment with Beijing Children's Hospital's B cell lymphoma protocol, but late relapse could be seen.