Precursor B-cell lymphoblastic lymphoma in childhood and adolescence: Clinical features, treatment, and results in trials NHL-BFM 86 and 90

Background. Precursor B-cell lymphoblastic lymphoma (PBLL) is a rare subtyp e of childhood non-Hodgkin lymphoma (NHL). The purpose of our study was to investigate frequency and clinicopathological features of PBLL in children and to test prospectively the efficacy of an ALL-type therapy for treatment of these patients. Procedure. From October, 1986, to March, 1995, 1,075 pa tients up to 18 years of age suffering from all kinds of NHL were registere d in the two consecutive multicenter studies NHL-BFM 86 and 90. Of these, 2 7 patients were diagnosed with PBLL. Twenty-one PBLL patients were treated according to a BFM-ALL-type protocol: an eight-drug induction over 9 weeks was followed by an 8-week consolidation including methotrexate 5 g/m(2) x4. Patients in stages I and II continued with maintenance up to a total thera py duration of 24 months, whereas patients in stages III and IV received an additional eight-drug intensification and cranial radiotherapy (12 Gy For prophylaxis) after consolidation. Six PBLL patients were treated according to the BFM-protocol for B-NHL, stratified according to stage and tumor load and consisting of two to six 5-day courses of chemotherapy. Results, The m edian age of the 27 patients with PBLL (18 boys, 9 girls) was 6.2 (range 0. 7-15) years. Stages (St. Jude) were: I (n = 3), II (n = 7), III (n = 9), an d IV (n = 8). Twenty-one PBLL patients had nodal disease, 6 patients had su bcutaneous manifestations, and 8 patients had bone marrow disease (<25% bla sts). All patients achieved remission. With a median follow-up time of 4.25 years, the estimated probability For event-tree survival (pEFS) at 10 year s for the total group was 0.73 (SE 0.10). Five patients (2, 1, 1, and 1 pat ients at stages I, 11, III, and IV, respectively) relapsed: 2 of 21 patient s who were treated according to the ALL strategy and 3 of 6 who were treate d according to the B-NHL-protocol. Conclusions. PBLL accounts for 2.5% of c hildhood NHL. An ALL-type therapy strategy appears to be superior to a shor t-pulse B-NHL protocol. (C) 2000 Wiley-Liss, Inc.