superiority of high dose chemotherapeutic regimens in the treatment of pediatric Non-Hodgkin's Lymphoma: results of a retrospective non randomized study of 103 evaluable cases

This retrospective study reviewed 160 previously untreated cases of pediatric Non Hodgkin's lymphoma referred to NEMPOCK between Jan. 1985-Dec. 1993. The treatment protocol adopted for these patients were the COMP regimen for undifferentiated, [small non cleaved], diffuse mixed and large cell subtypes while lymphoblastic lymphoma and T cell immunoblastic subtypes were treated by a modification of the CHOP regimen. During the study period 2 different dose levels of the treatment regimens were used: low dose regimens [1965-1989] and high dose regimens [1990-1993]. The response rate achieved among the 103 evaluable cases was significantly infavour of the high dose regimens being 85% and 86% for the COMP and CHOP respectively versus 57% and 60% [p< 0.05] for their low dose counter parts. C.N.S. relapse was seen in 10% with no significant benefit observed in patients received prophylactic cranial irradiation compared to those who received intrathecal chemotherapy alone. Relapse was reported in 9 out of the 70 cases who achieved complete remission [41%]. The relapse rate was reduced significantly [p=0.05] in patients treated by the high dose regimens compared to those treated by the low dose regimens [32% and 49% respectively]. A median follow up period of 64 months [range 24-129 months], the overall survival was significantly superior in patients treated by the high dose regimens compared to those treated by the low dose regimens being 59% and 31% respectively [p=0.03]. The following prognostic factors were significantly associated with poor prognosis: presence of bulky disease [p=0.0001], low dose regimens [p=0.007], stage IV disease [p=0.01] and initial CNS involvement [p=0.05]