• Asian Pacific Journal of Cancer Prevention
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• 제16권17호
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• pp.7523-7527
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• 2015

Background: Pediatric acute lymphoblastic leukemia (pALL) patients at King Abdulaziz Medical City represent a pure Saudi Arabian population. ETV6-RUNX1 positive pALL patients have good prognosis as compared to ETV6-RUNX1 negative counterparts. Therefore, frequencies of these two patient groups have a huge consideration in treatment strategies of pALL in a given population. Different geographical locations have been reported to have different frequencies of ETV6-RUNX1 ranging from 10% in Southeast Asia to 30% in Australia. Aim: Therefore, the objective of this study was to establish the ETV6-RUNX1 status of Saudi Arabian pALL patients and its association with clinical parameters and early remission. Materials and Methods: Clinical parameters and ETV6-RUNX1 status (using FISH technique) of pALL patients attending the Pediatric Oncology Clinic, King Abdulaziz Medical City, Riyadh from 2006 to 2011 were studied. Comparisons between ETV6-RUNX1 positive and negative groups were accomplished using chi-square test or Fisher's exact test. All statistical analyses were performed using SAS version 9.2 (SAS Institute, Inc., Cary, NC). Results: Out of 54 patients, 33 were male and 21 were females (ratio 1.57:1). B- and T-cell lineages were found in 47 (87%) and 7 (13%) patients respectively. Only 5 (9.3%) patients were ETV6-RUNX1 positive while 49(80.7%) were ETV6-RUNX1 negative. All ETV6-RUNX1 patients (100%) were of B-cell lineage and 80% (4/5) were in the 3-7 year age group. None of the ETV6-RUNX11 patients had ${\geq}5%$ blasts (no remission) at day 14 as compared with 9% in the ETV6-RUNX1 negative group (Figure 1). Conclusions: Frequency of ETV6-RUNX1 positive patients (less than 10%) in our pALL patients is much lower than reported for most European countries, North America, Australia and Japan while it is in accordance with ETV6-RUNX1 frequencies from Egypt (11.6%), Pakistan (10%), Spain (2%) and India (5-7%). This shows ethnic differences in genetics of pALL as well as higher frequencies of ETV6-RUNX1 positive pALL mostly in more industrialized countries, probably due to some industrial pollutants or westernized lifestyle.

• Asian Pacific Journal of Cancer Prevention
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• 제16권16호
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• pp.7343-7350
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• 2015

Genetic changes associated with acute lymphoblastic leukemia (ALL) provide very important diagnostic and prognostic information with a direct impact on patient management. Detection of chromosome abnormalities by conventional cytogenetics combined with fluorescence in situ hybridization (FISH) play a very significant role in assessing risk stratification. Identification of specific chromosome abnormalities has led to the recognition of genetic subgroups based on reciprocal translocations, deletions and modal number in B or T-cell ALL. In the last twelve years 102 newly diagnosed childhood/adult ALL bone marrow samples were analysed for chromosomal abnormalities with conventional G-banding, and FISH (selected cases) using specific probes in our hospital. G-banded karyotype analysis found clonal numerical and/or structural chromosomal aberrations in 74.2% of cases. Patients with pseudodiploidy represented the most frequent group (38.7%) followed by high hyperdiploidy group (12.9%), low hyperdiploidy group (9.7%), hypodiploidy (<46) group (9.7%) and high hypertriploidy group (3.2%). The highest observed numerical chromosomal alteration was high hyperdiploidy (12.9%) with abnormal karyotypes while abnormal 12p (7.5%) was the highest observed structural abnormality followed by t(12;21)(p13.3;q22) resulting in ETV6/RUNX1 fusion (5.4%) and t(9;22)(q34.1;q11.2) resulting in BCR/ABL1 fusion (4.3%). Interestingly, we identified 16 cases with rare and complex structural aberrations. Application of the FISH technique produced major improvements in the sensitivity and accuracy of cytogenetic analysis with ALL patients. In conclusion it confirmed heterogeneity of ALL by identifying various recurrent chromosomal aberrations along with non-specific rearrangements and their association with specific immunophenotypes. This study pool is representative of paediatric/adult ALL patients in Oman.

• Asian Pacific Journal of Cancer Prevention
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• 제13권7호
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• pp.3349-3355
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• 2012

Background and objectives: Chromosomal abnormalities play an important role in genesis of acute lymphoblastic leukemia (ALL) and have prognostic implications. Five major risk stratifying fusion genes in ALL are BCR-ABL, MLL-AF4, ETV6-RUNX11, E2A-PBX1 and SIL-TAL1. This work aimed to detect common chromosomal translocations and associated fusion oncogenes in adult ALL patients and study their relationship with clinical features and treatment outcome. Methods: We studied fusion oncogenes in 104 adult ALL patients using RT-PCR and interphase-FISH at diagnosis and their association with clinical characteristics and treatment outcome. Results: Five most common fusion genes i.e. BCR-ABL (t 9; 22), TCF3-PBX1 (t 1; 19), ETV6-RUNX1 (t 12; 21), MLL-AF4 (t 4; 11) and SIL-TAL1 (Del 1p32) were found in 82/104 (79%) patients. TCF3-PBX1 fusion gene was associated with lymphadenopathy, SIL-TAL1 positive patients had frequent organomegaly and usually presented with a platelets count of less than $50{\times}10^9/l$. Survival of patients with fusion gene ETV6-RUNX1 was better when compared to patients harboring other genes. MLL-AF4 and BCR-ABL positivity characterized a subset of adult ALL patients with aggressive clinical behaviour and a poor outcome. Conclusions: This is the first study from Pakistan which investigated the frequency of5 fusion oncogenes in adult ALL patients, and their association with clinical features, treatment response and outcome. Frequencies of some of the oncogenes were different from those reported elsewhere and they appear to be associated with distinct clinical characteristics and treatment outcome. This information will help in the prognostic stratification and risk adapted management of adult ALL patients.

• Asian Pacific Journal of Cancer Prevention
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• 제13권11호
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• pp.5469-5475
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• 2012

Background and Objectives: Acute lymphoblastic leukemia (ALL) is a complex genetic disease involving many fusion oncogenes (FO) having prognostic significance. The frequency of various FO can vary in different ethnic groups, with important implications for prognosis, drug selection and treatment outcome. Method: We studied fusion oncogenes in 101 pediatric ALL patients using interphase FISH and RT-PCR, and their associations with clinical features and treatment outcome. Results: Five most common fusion genes i.e. BCR-ABL t (22; 9), TCF3-PBX1 (t 1; 19), ETV6-RUNX1 (t 12; 21), MLL-AF4 (t 4; 11) and SIL-TAL1 (del 1p32) were found in 89/101 (88.1%) patients. Frequency of BCR-ABL was 44.5% (45/101). BCR-ABL positive patients had a significantly lower survival ($43.7{\pm}4.24$ weeks) and higher white cell count as compared to others, except patients with MLL-AF4. The highest relapse-free survival was documented with ETV6-RUNX1 (14.2 months) followed closely by those cases in which no gene was detected (13.100). RFS with BCR-ABL, MLL-AF4, TCF3-PBX1 and SIL-TAL1 was less than 10 months (8.0, 3.6, 5.5 and 8.1 months, respectively). Conclusions: This is the first study from Pakistan correlating molecular markers with disease biology and treatment outcome in pediatric ALL. It revealed the highest reported frequency of BCR-ABL FO in pediatric ALL, associated with poor overall survival. Our data indicate an immediate need for incorporation of tyrosine kinase inhibitors in the treatment of BCR-ABL+ pediatric ALL in this population and the development of facilities for stem cell transplantation.