Extramedullary infiltrates of AML are associated with CD56 expression, 11q23 abnormalities and inferior clinical outcome

Chang, Hong; Brandwein, Joseph; yi, Qi-Long; Chun, Kathy; Patterson, Bruce; Brien, Bill

doi:10.1016/j.leukres.2004.01.006

Next »Leukemia Research
Volume 28, Issue 10 , Pages 1007-1011, October 2004

Extramedullary infiltrates of AML are associated with CD56 expression, 11q23 abnormalities and inferior clinical outcome

Hong Chang
- Department of Laboratory Hematology, Princess Margaret Hospital, University Health Network, 610 University Ave., 4-320, Toronto, ON, Canada M50 2M9
- Corresponding author. Tel.: +1-416-946-4635; fax: +1-416-946-4616.
Joseph Brandwein
- Department of Medical Oncology and Hematology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Canada
Qi-Long yi
- Department of Biostatistics, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Canada
Kathy Chun
- Department of Pathology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Canada
Bruce Patterson
- Department of Laboratory Hematology, Princess Margaret Hospital, University Health Network, 610 University Ave., 4-320, Toronto, ON, Canada M50 2M9
Bill Brien
- Department of Laboratory Hematology, Princess Margaret Hospital, University Health Network, 610 University Ave., 4-320, Toronto, ON, Canada M50 2M9
- Department of Medical Oncology and Hematology, Princess Margaret Hospital, University Health Network, University of Toronto, Toronto, Canada

Received 11 September 2003; accepted 16 January 2004.

Abstract

We evaluated the frequency and prognostic significance of extramedullary infiltrates (EMI) at presentation of acute myeloid leukemia (AML) in adult patients. Of 331 cases with de novo AML, 101(30.5%) had extramedullary infiltrates at diagnosis. The extramedullary manifestations included: lymphadenopathy, splenomegaly, hepatomegaly, gingival hypertrophy, skin infiltrates and involvement of central nervous system (CNS). Patients with EMI had a high initial WBC count and a high proportion of M4/M5 morphological variants. The complete remission rate (CR) with induction chemotherapy was lower in patients with EMI (P=0.0077) and their overall survival was also inferior (P=0.0017). Flow cytometric evaluation of the surface antigens expressed by the leukemic blasts for CD34, TdT, HLADR, CD7, CD19 and CD56 found that only CD56 expression was associated with EMI. The association of CD56 expression with lymphadenopathy was statistically significant (P=0.035). Abnormal karyotypes were found in 50.6% of patients with EMI and 49.7% of patients without EMI. Only 11q23 abnormalities were associated with specific sites of EMI; lymphadenopathy (P=0.0111) and gingival hypertrophy (P=0.0016). Our study of adult AML patients demonstrates that EMI at diagnosis is associated with CD56 expression by leukemic blasts, 11q23 karyotypic abnormalities, low complete remission rate and poor overall survival.

Keywords: AML, Extramedullary disease, CD56, 11q23, Prognostic factors