Clinico-pathological impact of cytogenetic subgroups in B-cell chronic lymphocytic leukemia: experience from India.
BACKGROUND
The present study of 238 B-cell Chronic Lymphocytic Leukemia (B-CLL) patients were undertaken to seek the prevalence and to evaluate clinico-pathological significance of recurrent genetic abnormalities such as del(13q14.3), trisomy 12, del(11q22.3) (ATM), TP53 deletion, del(6q21) and IgH translocation/deletion.


METHODS
We applied interphase - fluorescence in situ hybridization (FISH) on total 238 cases of B-CLL.


RESULTS
Our study disclosed 69% of patients with genetic aberrations such as 13q deletion (63%), trisomy 12 (28%), 11q deletion (18%), 6q21 deletion (11%) with comparatively higher frequency of TP53 deletion (22%). Deletion 13q displayed as a most frequent sole abnormality. In group with coexistence of ≥2 aberrations, 13q deletion was a major clone indicating del(13q) as a primary event followed by 11q deletion, TP53 deletion, trisomy 12, 6q deletion as secondary progressive events. In comparison with del(13q), trisomy 12, group with coexistence of ≥2 aberrations associated with poor risk factors such as hyperleukocytosis, advanced stage, and multiple nodes involvement. In a separate study of 116 patients, analysis of IgH abnormalities revealed either partial deletion (24%) or translocation (5%) and were associated with del(13q), trisomy 12, TP53 and ATM deletion. Two of 7 cases had t(14;18), one case had t(8;14), and four cases had other variant IgH translocation t(?;14).


CONCLUSIONS
Detail characterization and clinical impact are necessary to ensure that IgH translocation positive CLL is a distinct pathological entity. Our data suggests that CLL with various cytogenetic subsets, group with coexistence of ≥2 aberrations seems to be a complex cytogenetic subset, needs more attention to understand biological significance and to seek clinical impact for better management of disease.
Cancer Cytogenetics Laboratory, Tata Memorial Hospital, Parel, Mumbai, Maharashtra, India.
P S Kadam
PS
Amare
V
V
Gadage
H
H
Jain
S
S
Nikalje
S
S
Manju
N
N
Mittal
S
S
Gujral
R
R
Nair
D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002869:Chromosome Aberrations; D005260:Female; D006801:Humans; D017404:In Situ Hybridization, Fluorescence; D007194:India; D015451:Leukemia, Lymphocytic, Chronic, B-Cell / Q000235:genetics* / Q000473:pathology*; D008297:Male; D008875:Middle Aged; D055815:Young Adult