6q Deletion Uncommon in CLL, But Should be Part of FISH Panel

[Guest guest]

British Journal of Haematology

Volume 132 Page 705 - March 2006

doi:10.1111/j.1365-2141.2005.05919.x

Volume 132 Issue 6

research paper

Chronic lymphocytic leukaemia profiled for prognosis using a

fluorescence in situ hybridisation panel

K. S. Reddy

Summary

A panel of fluorescence in situ hybridisation (FISH) probes was used

on 894 cases to target chromosome 11q, 13q, 17p deletions (del),

trisomy 12 (+12) in all and 6q deletion in 59. Chronic lymphocytic

leukaemia (CLL) immunophenotype (CD5 and CD19 with CD23) was found in

509 cases (average age 67¡¤7 years, 319 males and 190 females).

Among the 509 CLL cases 349 (68¡¤6%) had FISH (4-probe panel)

abnormalities: 160 del 13q [45¡¤8% (122-del 13q, 18-biallelic del 13q,

20-monoallelic/biallelic del 13q)], 71 tri 12 (20¡¤3%), 17 del ATM

(5%), 12 del p53 (3¡¤4%) and 89 ¡Ý 2 FISH abnormalities (25¡¤5%). Of

151/509 cases karyotyped, 108 were normal and 43 (43/151 = 28¡¤5%)

abnormal. Del 6q was found in 1/59 (1¡¤6%) FISH cases and in 6/151

(4%) karyotypes. In 14 CD23 negative cases IGH/BCL1 FISH detected t

(11;14) and was confirmed to be mantle cell lymphoma. Multiple

probes/panels that included IGH probe were ordered for 57 CLL cases,

11 had an IGH rearrangement with an unidentified partner.

This study favours the inclusion of del 6q and IGH probes in the CLL

panel. The FISH panel could also serve to monitor 13q deletion for

secondary changes with adverse prognosis. Understanding prognosis in

specific types of 13q deletion would enhance outcome prediction.