Cytogenetic abnormalities during clinical, immunophenotypic, and molecularremission in pediatric acute lymphoblastic leukemia

The significance of random cytogenetic abnormalities detected in pediatric acute lymphoblastic leukemia (ALL) during remission is unknown. We studied 10 of 72 consecutive ALL patients who developed cytogenetic abnormalities d uring clinical remission to determine their effect on remission status. The cytogenetic abnormalities occurred at a median of 14.5 months (range 5-72) from the initial diagnosis. Fire abnormalities were designated as clonal ( monosomy 21 in three metaphases and 64 similar to 69, XXY in three metaphas es from one patient at different times, and del(20)(q22q13) in three metaph ases, add(13)(q34) in two metaphases, and ?del(19)(p11) in two metaphases f rom three different patients). Ser en abnormalities were previously describ ed: del(5)(q12), del(5)(q33), -7, del(11)(q23), +12, and +13 each in one me taphase, and del(20)(q12q13) in three metaphases). The remaining cytogeneti c abnormalities rr ere nonclonal and random. Flow cytometry and analysis of IgH and TcR gene rearrangements showed that all evaluable patients were in immunophenotypic and molecular remission, respectively. Eight patients rem ain in clinical and molecular remission a median of 9 months (range 7-18) a fter detecting the cytogenetic abnormality, and the leukemia in two patient s has relapsed. During remission, cytogenetic abnormalities may not be a ha rbinger of leukemia relapse in pediatric ALL; therefore, a wait-and-see app roach is prudent. (C) Elsevier Science Inc., 2000. All rights reserved.