Favorable outcome for children and adolescents with T-cell lymphoblastic lymphoma with an intensive ALL-type therapy without local radiotherapy.

Abstract

In study NHL-BFM 90 we investigated the efficacy of an ALL-type treatment without local radiotherapy for childhood T-cell lymphoblastic lymphoma (T-LBL). In particular, the prognostic impact of the speed of tumor regression was evaluated. From April 1990 to March 1995, 105 evaluable patients, 1.1-16.4 years of age, with T-LBL were enrolled into study NHL-BFM 90. Patients with stage I and II received an 8-drug induction followed by a consolidation including high-dose-methotrexate (MTX) and maintenance therapy up to a total therapy duration of 24 months. Patients with stage III and IV received an additional reinduction and cranial radiotherapy (CRT) (12 Gy for prophylaxis) between consolidation and maintenance. Residual tumor after completion of induction had to be resected. No local RT was applied. Patients received intensified chemotherapy if tumor regression on day 33 of induction was <70% or when vital residual tumor was present after the induction phase. With a median follow-up of 6.41 years, pEFS at 5 years is 91.4% (SE+/-2.7%). 101 patients were evaluable for the speed of tumor response. Two patients received intensified therapy due to <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. Our data demonstrate that, with intensive ALL-type chemotherapy but no local radiotherapy, an event-free survival rate of 90% can be achieved in childhood T-LBL. Providing tumor regression within 5 weeks is sufficient, tumor remnants after induction have weak prognostic impact.