Abstract. Relapsed or refractory B-cell non-Hodgkin's lymphoma (B-NHL) patients have a poor prognosis. New treatment modalities have been used to improve survival rates in children with relapsed or refractory B-NHL. CD20 is expressed in >98% of childhood B-NHL and a chimeric anti-CD20 monoclonal antibody, rituximab, is increasingly being used at relapse. The aim of the present study was to determine the efficacy of rituximab on relapsed B-NHL. Three B-NHL cases were treated successfully with a combination of intensive chemotherapy protocol plus rituximab.
IntroductionLymphomas are the third most common type of cancer identified during childhood and adolescence, with 60% of those being mature B-cell non-Hodgkin's lymphoma (B-NHL). Primary central nervous system malignant lymphomas (PCNSLs) comprise <2% of malignant lymphomas. B-NHL is usually of B-cell origin (1-4). First-line chemotherapy is found to be effective in the majority of children diagnosed with B-NHL. Although long-term cure rates are 75% for high-risk disease (5), relapses occur in ~20% of the patients, almost always within a year from diagnosis (6). Relapsed or refractory B-NHL has a poor prognosis. CD20 is expressed in >98% of childhood B-NHL and increasingly a chimeric anti-CD20 monoclonal antibody, rituximab, is being used at relapse (7,8). Although rituximab is commonly used as a first-line therapy in adults, the effect of rituximab in children with B-NHL has yet to be adequately investigated (9-12). Three B-NHL cases were investigated in this case study to determine the efficacy of rituximab-containing regimens on relapsed B-NHL.
Case reportsPatient 1. A 16-year-old male was admitted to the Department of Pediatric Oncology complaining of recurrent abdominal pain and distention for the previous 2 months. Physical examination revealed that the abdomen was distended but non-tender, with an immobile, painless and hard mass, 5x8 cm in diameter, located on the right side of the abdomen. Results of bone marrow (BM) examination, hematologic and basic metabolic analysis were normal. Abdominal computed tomography (CT) scan confirmed multiple retroperitoneal lymph nodes and a mass, 6x10x11 cm in a diameter, surrounding the superior mesenteric artery (Fig. 1A). Burkitt lymphoma was diagnosed. Positive CD20, CD10, bcl6 and negative CD30, CD3, CD5 and TdT were reported by immunohistochemical examination. After 4 months of NHL-Berlin-Frankfurt-Muenster (BFM) 95 chemotherapy protocol, the patient noted backache. BM examination revealed diffuse L3 type lymphoblasts. Additionally, the CT scan showed that the size of the intra-abdominal mass did not decrease. The patient received intravenous rituximab (375 mg/m 2 /dose/once every 3 weeks) for six doses and Ifosfamide, Carboplatin and Etoposide (ICE). The control CT scan revealed that the size of the mass decreased and central necrosis was evident (Fig. 1B). Although in complete remission at least 12 months following chemotherapy, the patient succumbed due to systemic progression of severe sepsis.Patient 2. A 14-y...