Relapsed/refractory pediatric B‐cell non‐Hodgkin lymphoma treated with rituximab combination therapy: A report from the Japanese Pediatric Leukemia/Lymphoma Study Group

Pediatric relapsed/refractory (R/R) B-cell non-Hodgkin lymphoma (B-NHL) has been reported to be extremely difficult to cure, but rituximab is expected to be effective in improving the prognosis of pediatric R/R B-NHL patients. Here, we assessed the treatment and prognosis of pediatric R/R B-NHL in the rituximab era in Japan.We collected information on patients with R/R B-NHL who were registered with the Japanese Pediatric Leukemia/Lymphoma Study Group (JPLSG) B-NHL03 protocol, a nationwide multicenter trial for newly diagnosed patients. We assessed the treatment and outcome of 33 pediatric R/R B-NHL cases.Twenty-eight patients received rituximab combination therapy as salvage treatment. R-ICE (rituximab, ifosfamide, carboplatin, and etoposide), the most common regimen, was used in 22 patients as first-line salvage therapy. Twenty-three patients received hematopoietic stem cell transplantation (HSCT). Among all 33 patients, 23 (70.0%) achieved partial remission or complete remission. Their 5-year overall survival rate was 48.5%, which was far superior to that in both our previous study and in another study on pediatric R/R B-NHL. Four toxic deaths associated with viral infection occurred after allogeneic HSCT following on rituximab combined salvage therapy. Risk factor multivariate analysis for survival in patients receiving rituximab combination therapy showed central nervous system combined relapse had inferior outcome.The prognosis of pediatric R/R B-NHL in a Japanese cohort remained poor but is showing improvement in the rituximab era. Rituximab combination therapy is effective for R/R B-NHL patients who did not receive rituximab as primary treatment. We need to consider possible viral infections in allogeneic HSCT after rituximab treatment.