PART I. RELAPSE PATTERNS AND SURVIVAL IN UNMAlNTAlNED REMISSION

Abstract

ABSTRACTNygaard, R. and Moe, P. J. (Department of Paediatrics, University Hospital,‘Ikondheim, Norway). Outcome after cessation of therapy in childhood leukemia. A population‐based Nordic study of 986 patients.) I: Relapse patterns and survival in unmaintained remission. Acta Paediatr Scand Suppl 354: 5, 1989.This follow‐up study includes all Nordic patients whose antileukemic therapy was electively discontinued by January 1, 1985. The patients were observed 2–25 years after cessation of therapy for leukemia diagnosed before age 15, and only 1.4% of them were lost to follow‐up. Outcome was evaluated in terms of relapse patterns and disease‐free survival (DFS) after cessation of therapy.Relapse occurred in 21.3% of the patients after treatment was discontinued. The overall estimated proportion still in remission ten years after cessation was 0.76. There were no national dissimilarities, and DFS for ALL vs. AML was not significantly different. For patients who were treated with bone marrow transplantation in fust remission (n= 32), subsequent 5‐year DFS was 0.93 in ALL and 0.83 in AML.When analyzed according to variables with possible influence on prognosis, treatment period had statistically significant influence on DFS. In ALL, five‐year DFS improved from 0.73 to 0.83 during the study. Age at diagnosis did not influence outcome.In both types of acute leukemias, girls had a significantly higher DFS than boys. The occurrence of isolated testicular relapses in boys could fully account for this difference in ALL.For patients who had received prophylactic treatment of the CNS during the first 7 years it was offered, outcome was less favourable in cases who had radiotherapy than in those without irradiation. The differences in estimated DFS, mortality and incidence of CNS relapses were statistically significant. However, there was no significant difference in outcome between the two treatment group later in the study.The long observation time has revealed 7 recurrences of ALL after more than 5 years in unmaintained remission, and 7 cases of secondary malignancies.