Prognostic significance of myeloid‐associated antigen expression on blast cells in children with acute lymphoblastic leukemia

Abstract

The prognostic significance of expression of myeloid-associated antigens in childhood acute lymphoblastic leukemia (myA+ALL) was evaluated. From 1984 to 1990, 251 children with immunologically verified ALL were treated in two prospective consecutive Austrian studies. Complete immunophenotyping was performed in 206 cases (82%). Out of these 175 cases were classified as B-cell precursor ALL, 31 cases as T-ALL. Expression of myeloid-associated antigens was demonstrated in 23 cases (13.1%) of childhood B-cell precursor ALL, particularly in immature (CD10 negative) forms (P < .0001), and in 1 case (3.2%) of T-ALL. CDw65 was expressed most frequently (12 cases), followed by CD13 and CD15 (5 cases each), CD33 (4 cases), and blood-group H (3 cases). Compared to myA- ALL prognosis of children with myA+ B-cell precursor ALL was poor, despite intensive multiagent chemotherapy according to BFM protocols. Remission rates were not impaired, but pEFS was 74.6% for myA- ALL, and only 37.8% for myA+ ALL (P = .0001). As demonstrated by multivariate analysis the expression of myeloid-associated antigens was the most important prognostic variable for EFS in B-cell precursor ALL, whether or not CD10 was expressed.

The majority of myeloid‐antigen‐positive (My+) childhood B‐cell precursor acute lymphoblastic leukaemias express TEL‐AML1 fusion transcripts

“…The published prognostic significance of myeloid associated antigen expression is variable; some studies have suggested that myeloid antigen expression is an independent factor of bad prognosis (Fink et al, 1993;Kurec et al, 1991;Wiersma et al, 1991) whereas other larger studies have demonstrated no statistical differences in DFS or survival (Borowitz et al, 1991;Ludwig et al, 1990;Pui et al, 1991). It has been reported that TEL-AML1-positive cases have a favourable prognosis (Shurtleff et al, 1995).…”

Therapy of Acute Lymphoblastic Leukemia in Adults (ALL)

“…The incidence depends on definition criteria and is approximately 18% in adults. In earlier pediatric studies LFS in My+ patients (38-39%) was significantly lower compared to My-patients (75-78%) [27,28], More recent studies could not confirm these results [29]. Also in adult ALL the prognostic impact My+ subtype is not yet proven and requires further investigation.…”

Correlation of CD33 with poorer prognosis in childhood ALL implicates a potential of anti-CD33 frontline therapy

“…These papers followed a period of controversy between studies showing significantly worse prognosis of MyAg pos ALL [7][8][9] or no difference. 10 However, recent in vitro data showed a higher resistance for ALL blasts with MyAgs.…”