Intensive ALL-type Therapy Without Local Radiotherapy Provides a 90% Event-free Survival for Children with T-cell Lymphoblastic Lymphoma: a BFM Group Report

The purpose of our study was to investigate the efficacy of an acute lymphoblastic leukemia (ALL)-type treatment with moderate-dose, prophylactic cranial irradiation and without local radiotherapy for childhood T-cell lymphoblastic lymphoma (T-LBL). From April 1990 to March 1995, 105 evaluable patients, 1.1 to 16.4 years of age, with T-LBL were enrolled in study NHL-BFM 90 (non-Hodgkin's lymphoma-Berlin-Frankfurt-Munster 90). They received an 8-drug induction over 9 weeks followed by an 8-week consolidation including methotrexate (MTX) 5 g/m(2) x 4. Patients with stage I (n = 2) and II (n = 2) continued with maintenance therapy (6-mercaptopurine daily and MTX weekly, both orally) until a total therapy duration of 24 months. Patients with stage III (n = 82) and IV (n = 19) received an 8-drug intensification over 7 weeks and cranial radiotherapy (12 Gy for prophylaxis) after consolidation, followed by maintenance. Residual tumor after induction had to be resected. Patients received intensified chemotherapy if tumor regression on day 33 of induction was less than 70% or when vital residual tumor was present after the complete induction phase. With a median follow-up of 4.5 years, the estimated event-free survival at 5 years is 90% (95% confidence interval, 82%-100%). Events were 1 early death, 8 tumor failures, and 1 secondary acute myeloid leukemia. A total of 101 patients were evaluable for the speed of tumor response. Two patients received intensified therapy due to less than 70% tumor regression on day 33. Of 19 patients with tumor residues after induction, 2 relapsed as compared to 4 of 80 patients with complete tumor regression. We conclude that, with intensive ALL-type chemotherapy including moderate cumulative doses of anthracyclines 240 mg/m(2) and cyclophosphamide (3 g/m(2)) and moderate-dose prophylactic cranial irradiation but no local radiotherapy, an event-free survival rate of 90% can be achieved in childhood T-LBL. (Blood. 2000;95:416-421)