[1460] Myelodysplastic Syndromes with Interstitial Deletions of 11q Lack Cryptic 11q23 Translocations and Exhibit Characteristic Clinicopathologic Features

SA Wang, LV Abruzzo, RP Hasserjian, LJ Medeiros, RN Miranda. UT MD Anderson, Houston, TX; Massachusetts General Hospital, Boston, MA

Background: Interstitial deletions of 11q [del(11)q] as part of a non-complex karyotype is infrequent in myelodysplastic syndromes (MDS), leaving the clinicopathologic and genetic features largely undefined. Cryptic translocation involving MLL gene has been found in some acute myeloid leukemia (AML) with del(11)q, but has not been investigated in MDS patients.
Design: We searched the data files of three large medical centers over a 10-year period and identified 30 MDS cases with variable region deletions of 11q13q26 in a non-complex karyotype. Fluorescence in situ hybridization (FISH) with probe to 11q23 was performed on MDS and 17 AML with del(11)q.
Results: 11q deletion was observed as a sole abnormality in 23 cases and was associated with another abnormality in 7 showing a 0.6% frequency in MDS. The most common additional abnormality was del(5)(q13q33), in 4 of 7 cases. There were 14 men and 16 women, with a median age of 68 years. Patients presented with various degrees of cytopenia(s), and 11 of 25 (44%) were transfusion-dependent. These cases were classified as 2 RA; 1 RARS; 2 RCUD; 14 RCMD; 1MDS-U; 8RAEB-1; 1 RAEB-2; 1 t-MDS. Bone marrow showed >15% ring sideroblasts (RS) in 14/28 (50%) cases. With a median follow-up of 28 months, the overall survival (OS) was 32 months, an OS falling between patients with good and intermediate risk cytogenetics, and better than poor risk group (p=0.228, p=0.448, and p=0.0005, respectively), comparing to our historic data consisting of 1165 MDS patients.

FISH confirmed 11q23 deletion, but no evidence of cryptic 11q23 translocations in all 11 MDS cases tested. By contrast, FISH showed 11q23 translocation in 4/17 (24%) AML with del(11)q.
Conclusions: Del(11)q occurring as a sole abnormality or part of a non-complex karyotype are predominantly associated with primary MDS, lack of cryptic 11q23 translocation, and represent a risk between good and intermediate cytogenetics. The fact that a substantial number of cases had increased RS suggests that del(11)q may aggravate impaired heme-synthesis in MDS, leading to transfusion-dependent anemia.
Category: Hematopathology

Wednesday, March 24, 2010 1:00 PM

Poster Session VI # 191, Wednesday Afternoon

 

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