Prevalence of common fusion transcripts in acute lymphoblastic leukemia: A report of 304 cases.
OBJECTIVE
Information about fusion transcripts in acute lymphoblastic leukemia (ALL) is used to risk-stratify patients, decide on the treatment and to detect minimal residual disease. This study was conducted to determine the frequency of common fusion transcripts BCR-ABL, TEL-AML1, MLL-AF4 and E2A-PBX1 for B-ALL and SIL-TAL1 for T-ALL as seen at a tertiary care center in India.


METHODS
Up to 304 new cases of ALL (271 B-ALL and 33 T-ALL) diagnosed on morphology, cytochemistry and immunophenotyping were studied. All were screened for the common fusion transcripts by RT-PCR.


RESULTS
Both our B- (218/271; 80.4%) and T-ALL (26/33; 78.8%) patients were largely children. In the B-ALL children, BCR-ABL was detected in 26/218 (11.9%), E2A-PBX1 in 13/218 (5.9%), TEL-AML1 in 16/218 (7.3%) and MLL-AF4 in 3/218 (1.4%) patients. Adult B-ALL cases had BCR-ABL in 15/53 (28.3%) and E2A-PBX in 2/53 (3.8%); however, no other fusion transcript was detected. SIL-TAL1 was found in four of 26 pediatric (15%) and zero of 7 adult T-ALL cases.


CONCLUSIONS
The higher incidence of BCR-ABL and lower incidence of TEL-AML1 in our ALL patients, both in children and adults as compared with the West, suggests that patients in India may be biologically different. This difference may explain at least in part the higher relapse rate and poorer outcome in our B-ALL cases.
Department of Laboratory Oncology, IRCH, New Delhi, India.
Anita
A
Chopra
Department of Laboratory Oncology, IRCH, New Delhi, India.
Sushant
S
Soni
Department of Laboratory Oncology, IRCH, New Delhi, India.
Deepak
D
Verma
Department of Laboratory Oncology, IRCH, New Delhi, India.
Dev
D
Kumar
Department of Laboratory Oncology, IRCH, New Delhi, India.
Rahul
R
Dwivedi
Department of Laboratory Oncology, IRCH, New Delhi, India.
Anjali
A
Vishwanathan
Department of Laboratory Oncology, IRCH, New Delhi, India.
Garima
G
Vishwakama
Department of Medical Oncology, IRCH, New Delhi, India.
Sameer
S
Bakhshi
Department of Pediatric Oncology, All India Institute of Medical Sciences, New Delhi, India.
Rachna
R
Seth
Department of Medical Oncology, IRCH, New Delhi, India.
Ajay
A
Gogia
Department of Medical Oncology, IRCH, New Delhi, India.
Lalit
L
Kumar
Department of Laboratory Oncology, IRCH, New Delhi, India.
Rajive
R
Kumar
D000293:Adolescent; D000328:Adult; D000368:Aged; D002648:Child; D002675:Child, Preschool; D050676:Core Binding Factor Alpha 2 Subunit / Q000235:genetics*; D005260:Female; D016044:Fusion Proteins, bcr-abl / Q000235:genetics*; D006801:Humans; D016130:Immunophenotyping; D007194:India / Q000453:epidemiology; D007223:Infant; D007231:Infant, Newborn; D008297:Male; D008875:Middle Aged; D018365:Neoplasm, Residual / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D015514:Oncogene Proteins, Fusion / Q000235:genetics*; D054198:Precursor Cell Lymphoblastic Leukemia-Lymphoma / Q000453:epidemiology / Q000235:genetics* / Q000473:pathology; D015995:Prevalence; D012189:Retrospective Studies; D055815:Young Adult; D000097764:ETS Translocation Variant 6 Protein
D050676:Core Binding Factor Alpha 2 Subunit; D016044:Fusion Proteins, bcr-abl; D015514:Oncogene Proteins, Fusion; C102421:TEL-AML1 fusion protein; D000097764:ETS Translocation Variant 6 Protein
acute lymphoblastic leukemia; common fusion transcript; prevalence