Clinical significance of CD56 expression in patients with acute promyelocytic leukemia treated with all-trans retinoic acid and anthracycline-based regimens

Abstract

The expression of CD56 antigen in acute promyelocytic leukemia (APL) blasts has been associated with short remission duration and extramedullary relapse. We investigated the clinical significance of CD56 expression in a large series of patients with APL treated with all-trans retinoic acid and anthracycline-based regimens. Between 1996 and 2009, 651 APL patients with available data on CD56 expression were included in 3 subsequent trials (PETHEMA LPA96 and LPA99 and PETHEMA/HOVON LPA2005). Seventytwo patients (11%) were CD56 ؉ (expression of CD56 in > 20% leukemic promyelocytes). CD56 ؉ APL was significantly associated with high white blood cell counts; low albumin levels; BCR3 isoform; and the coexpression of CD2, CD34, CD7, HLA-DR, CD15, and CD117 antigens. For CD56 ؉ APL, the 5-year relapse rate was 22%, compared with a 10% relapse rate for CD56 ؊ APL (P ‫؍‬ .006). In the multivariate analysis, CD56 expression retained the statistical significance together with the relapse-risk score. CD56 ؉ APL also showed a greater risk of extramedullary relapse (P < .001). In summary, CD56 expression is associated with the coexpression of immaturity-associated and T-cell antigens and is an independent adverse prognostic factor for relapse in patients with APL treated with all-trans-retinoic acid plus idarubicin-derived regimens. This marker may be considered for implementing riskadapted therapeutic strategies in APL. The LPA2005 trial is registered at http:// www.clinicaltrials.gov as NCT00408278. (Blood. 2011;117(6):1799-1805)

How to manage acute promyelocytic leukemia

“…39 Although it is reported from time to time that CD56 expression in patients with APL may be an independent factor predicting poor prognosis, further confirmation is needed. 40,41 We agree with the views of Sanz et al 42 that three simultaneous actions should be done when a diagnosis of APL is suspected: the start of ATRA therapy before confirmation of the diagnosis; institution of supportive measures; and rapid confirmation of genetic diagnosis. As Tallman et al 5 mentioned, bleeding is the most dangerous complication and represents a major cause of early death (ED) for the newly diagnosed APL patients.…”

Introducing biological features at diagnosis improves the relapse risk stratification in patients with acute promyelocytic leukemia treated with ATRA and chemotherapy

“…This concern is reflected by the fact that although bone marrow involvement according to BMB has been established as an important adverse prognostic factor in DLBCL [7], this is not the case for FDG-PET/CT-based bone marrow involvement. Of the five studies that reported the prognostic value of bone marrow involvement at FDG-PET/CT in DLBCL [2,[8][9][10][11], four showed that FDG-PET/CTbased bone marrow status did not have any prognostic value at all [2,[8][9][10]. These observations suggest that false-positive FDG-PET/CT results occur in a considerable proportion of patients with DLBCL and that increased FDG uptake of the marrow is not sufficient evidence to designate advanced-stage disease.…”

“…In all cases, records were available for complete blood counts, peripheral blood and bone marrow blast infiltration, type of PML/RARA fusion gene, coagulation laboratory parameters, morphologic variant, FLT3-ITD presence, and CD34 expression. Our group and others previously reported of a negative prognostic value of CD56, but in this study we did not consider this antigen for the low rate of positivity in our cohort [8,9]. Molecular tests for PML/RARA monitoring were performed after the third consolidation and then every three months for two years and every six months after the end of maintenance.…”

Clinical impact of FLT3 mutation load in acute promyelocytic leukemia with t(15;17)/PML-RARA

“…Based on previous observations that expression of CD56 was correlated with higher relapse risk in APL, [27][28] we evaluated this parameter in 43 patients with available immunophenotypic data. CD56 expression greater than 20% was seen in 6/43 cases (14.0%) which was comparable to the frequency in the mentioned studies.…”