EXPRESSION OF MYELOID MARKERS LACKS PROGNOSTIC IMPACT IN CHILDREN TREATED FOR ACUTE LYMPHOBLASTIC-LEUKEMIA - ITALIAN EXPERIENCE IN AIEOP-ALL 88-91 STUDIES

The importance of coexpression of myeloid antigens in childhood acute lymphoblastic leukemia (ALL) has long been debated; results are confli cting. We studied children with ALL treated at Italian Association for Pediatric Hematology-Oncology (AIEOP) institutions over 6 years with Berlin-Frankfurt-Muenster (BFM)-based protocols and have analyzed the incidence of coexpression of six MyAg (CD11b, CD13, CD14, CD15, CD33, CD65w) to determine its prognostic impact. Criteria for MyAg coexpress ion (MyAg(+)ALL) included positivity to one or more MyAg on at least 2 0% of blasts and confirmation of coexpression at double-fluorescence a nalysis. A total of 291 of 908 cases were MyAg+ALL (32%). Incidence wa s similar in B-ALL and T-ALL; among common, pre-B, and pre-pre-B-ALL. CD13 and CD33 were most common. Patients with MyAg(+)ALL had presentin g features similar to MyAg(-)ALL. They entered standard or intermediat e risk protocols more frequently and had better prednisone response, b ut similar complete remission rates. Six-year event-free survival (EFS ) was 69.0% in 291 MyAg(+)ALL cases and 65.3% in 617 MyAg(-)ALL cases, without significant difference. Cases expressing two or more MyAg pre sented similar clinical features and treatment response. MyAg(+)ALL ha d worse EFS only in infants (0% v 47%) (P =.01). Therefore, in this se ries of homogeneously diagnosed and treated ALL, coexpression of MyAg was not associated with prognostic significance, without relevance for clinical purposes or for patient stratification, except for infants. (C) 1998 by The American Society of Hematology.