1: Haematologica 2001 Dec;86(12):1245-53 Related Articles, Books, LinkOut

Fluorescence in situ hybridization study of TEL/AML1 fusion and other abnormalities involving TEL and AML1 genes. Correlation with cytogenetic findings and prognostic value in children with acute lymphocytic leukemia.

Martinez-Ramirez A, Urioste M, Contra T, Cantalejo A, Tavares A, Portero JA, Lopez-Ibor B, Bernacer M, Soto C, Cigudosa JC, Benitez J.

Dpto. de Genetica Humana, Programa de Patologia Molecular, Centro Nacional de Investigaciones Oncologicas (CNIO), Ctra. Majadahonda-Pozuelo, Km. 2, 28220 Majadahonda, Madrid, Spain. angmartinez@cnio.es

BACKGROUND AND OBJECTIVES. The TEL/AML1 fusion is the most common genetic abnormality found in childhood acute lymphoblastic leukemias (ALL). Although it is very difficult to identify by conventional cytogenetic techniques it can be readily detected using fluorescence in situ hybridization (FISH). We carried out cytogenetic and FISH studies on 42 children with ALL in order to know the frequency of this translocation in our population, the incidence of TEL and/or AML1 gene alterations, and their correlation with clinical evolution and prognosis. In addition, we performed reverse transcription polymerase chain reaction (RT-PCR) in some cases, confirming the feasibility of FISH techniques in the detection of this translocation. DESIGN AND METHODS. Bone marrow samples were obtained from 42 childhood ALL patients. The copy number of AML1 and TEL genes were studied using fluorescent in situ hybridization with a dual color DNA probe specific for the AML1 and TEL genes. RESULTS. We found a frequency of TEL/AML1 fusion of 17% in our sample. Double TEL/AML1 fusion, lack of TEL signal and extra AML1 signals were frequent additional FISH abnormalities. Duplication of a chromosomal complement, deletion of chromosome 12p arm, and polysomies of chromosome 21 are plausible explanations for these additional FISH findings. However, a relatively high proportion of our cases (9.5%) presented specific amplification of AML1. A statistically significant difference in prognosis was found between patients with and without these additional AML1 or TEL FISH alterations (p<0.02), which could be related to the presence of specific karyotypes. INTERPRETATIONS AND CONCLUSIONS. The frequency of TEL/AML1 fusion is similar to that found in other populations (17%). We found that FISH analysis of AML and TEL is related to the evolution of the disease. The absence of alterations in these genes revealed by FISH could be indicative of bad prognosis, while the presence of alterations is related to a good evolution. Our results suggest that interphase FISH analysis to search for alterations in AML and TEL genes could be extremely useful for complementing cytogenetic studies and for providing additional information about the possible outcome of the disease in patients with ALL.

PMID: 11726315 [PubMed - in process]

1: Cas Lek Cesk 2001 Aug 30;140(17):519-24 Related Articles, Books

[Fluorescent in situ hybridization (FISH) in the diagnosis of acute childhood lymphatic leukemia (ALL)]

[Article in Czech]

Zemanova Z, Michalova K, Brezinova J, Sindelarova L, Kurkova S, Smisek P, Zuna J, Trka J, Stary J.

III. interni klinika 1. LF UK a VFN, Praha. zuze@vfn.cz

Classical cytogenetic analysis plays an important role in the diagnosis, classification, therapy monitoring and prognosis of patients with leukemia. Many recurrent cytogenetic abnormalities with major prognostic values have been described in childhood ALL. Hyperdiploidy and/or t(12;21) are associated with good prognosis, whereas t(9;22) and/or rearrangements of MLL gene correlate with poor outcome and therefore early detection of these abnormalities is very important. FISH can overcome some limitations of conventional cytogenetic and molecular-genetic analyses and due to high sensitivity specific chromosomal aberrations in mitoses and/or interphase nuclei can be detected. In the Center of Oncocytogenetics of the 3rd Medical Department for assessment of hyperdiploidy and structural rearrangements we use double-color FISH with centromeric and/or locus-specific probes and complex aberrations are ascertained by whole chromosome painting probes and multicolor FISH. Among 275 children with ALL examined during the last 8 years by different FISH methods we found seven patients with translocation t(9;22) and 14 patients with MLL rearrangements in bone marrow cells. Since 1988 we focus on detection of hyperdiploidy and/or t(12;21). High hyperdiploidy was found in 35 children, 10 of them had further complex rearrangements. Translocation t(12;21) was proved in 37 patients and complex rearrangements were found in 22 of them. FISH, cytogenetic and molecular-genetic analyses become obligatory for the first diagnostic examination as well as for monitoring of treatment effect in children with ALL.

Publication Types: Review Review, Tutorial

PMID: 11702476 [PubMed - indexed for MEDLINE]

1: Best Pract Res Clin Haematol 2001 Sep;14(3):593-607 Related Articles, Books, LinkOut

Acute lymphoblastic leukaemia.

Harrison CJ.

Leukaemia Research Fund/UK Cancer Cytogenetics Group Karyotype Database in Acute Lymphoblastic Leukaemia, Department of Haematology, Royal Free and University College School of Medicine, Rowland Hill Street, London, NW3 2PF, UK.

In acute lymphoblastic leukaemia (ALL) the karyotype provides important prognostic information which is beginning to have an impact on treatment. The most significant structural chromosomal changes include: the poor-risk abnormalities; t(9;22)(q34;q11), giving rise to the BCR/ABL fusion and rearrangements of the MLL gene; abnormalities previously designated as poor-risk; t(1;19)(q23;p13), producing the E2A/PBX1 and rearrangements of MYC with the immunoglobulin genes; and the probable good risk translocation t(12;21)(p13;q22), which results in the ETV6/AML1 fusion. These abnormalities occur most frequently in B-lineage leukaemias, while rearrangements of the T cell receptor genes are associated with T-lineage ALL. Abnormalities of the short arm of chromosome 9, in particular homozygous deletions involving the tumour suppressor gene (TSG) p16(INK4A), are associated with a poor outcome. Numerical chromosomal abnormalities are of particular importance in relation to prognosis. High hyperdiploidy (51-65 chromosomes) is associated with a good risk, whereas the outlook for patients with near haploidy (23-29 chromosomes) is extremely poor. In view of the introduction of risk-adjusted therapy into the UK childhood ALL treatment trials, an interphase FISH screening programme has been developed to reveal chromosomal abnormalities with prognostic significance in childhood ALL. Novel techniques in molecular cytogenetics are identifying new, cryptic abnormalities in small groups of patients which may lead to further improvements in future treatment protocols. Copyright 2001 Harcourt Publishers Ltd.

Publication Types: Review Review, Tutorial

PMID: 11640871 [PubMed - indexed for MEDLINE]

1: Br J Haematol 2001 Sep;114(4):786-93 Related Articles, Books, LinkOut

Interphase fluorescence in situ hybridization and spectral karyotyping reveals hidden genetic aberrations in children with acute lymphoblastic leukaemia and a normal banded karyotype.

Nordgren A, Schoumans J, Soderhall S, Nordenskjold M, Blennow E.

Department of Molecular Medicine, L8-02 Karolinska Hospital, SE-171 76 Stockholm, Sweden. ann.nordgren@cmm.ki.se

Twenty-two cases of childhood acute lymphoblastic leukaemia (ALL) with normal G- or Q-banded karyotypes were studied by interphase fluorescence in situ hybridization (FISH) and spectral karyotyping. Probes detecting MLL, BCR/ABL and TEL/AML1 rearrangements were used for the interphase studies, along with centromere-specific probes from chromosomes 17 and X. In 10 patients (45%), previously undetected aberrations were demonstrable. Specific gene rearrangements and structural changes were found in six cases and numerical changes in five. Five of these aberrations have previously been reported to have an impact on prognosis. Three cases were massively hyperdiploid and, in one, the prognostically important BCR/ABL fusion was detected. In addition, a near-haploid karyotype with 27 chromosomes was found in one patient and TEL/AML1 rearrangements were detected in two cases. This study indicates that about half of childhood ALL cases with apparently normal karyotypes harbour genetic aberrations that may be detected using interphase FISH and spectral karyotyping.

PMID: 11564064 [PubMed - indexed for MEDLINE]

1: Am J Hematol 2001 Oct;68(2):91-8 Related Articles, Books, LinkOut

TEL/AML1 rearrangement and the prognostic significance in childhood acute lymphoblastic leukemia in Hong Kong.

Tsang KS, Li CK, Chik KW, Shing MM, Tsoi WC, Ng MH, Lau TT, Leung Y, Yuen PM.

Hematology and Bone Marrow Transplantation Division, Department of Anatomical and Cellular Pathology, Chinese University of Hong Kong, Prince of Wales Hospital, Hong Kong, China.

The TEL/AML1 rearrangement has been implicated as an independent good prognostic factor in pediatric acute lymphoblastic leukemia (ALL). We examined TEL/AML1 using nested reverse-transcription polymerase chain reaction (RT-PCR) and correlated TEL/AML1 with cytogenetics and immunophenotypes in 75 consecutively analyzed Chinese children with ALL in Hong Kong. TEL/AML1 was detected in 17.9% (12/67) B-lineage ALL at diagnosis but not in 8 T-ALL children or in 34 adults with ALL. E2A/PBX1, MLL/AF4, and BCR/ABL were not found in TEL/AML1+ patients. Coexpression of cross-lineage antigens was associated with TEL/AML1 gene fusion (p = 0.032), with CD13 in 80% (4/5) TEL/AML1+ cohort. Chromosomal abnormalities were demonstrated in 50% of the TEL/AML1+ ALL; however, a cryptic t(12;21) was not detected in these cases. Hyperdiploidy of 47-48 chromosomes was encountered in 25%. Deletion of 12p resulting in the loss of the normal allele of TEL and nonspecific del(6q) were noted in 8% (1/12) and 25% (3/12) of the TEL/AML1+ children, respectively. Rapid clearance of TEL/AML1 was noted in 50% of the patients on completion of the induction therapy; however, 16.7% (2/12) TEL/AML1+ ALL relapsed at a mean of 48.6 months from diagnosis (25 months off-therapy). The incidence of relapses of TEL/AML1+ ALL was comparable to that at diagnosis in B-lineage ALL (14.3% [2/14] vs. 17.9% [12/67], p > 0.05). The relapse rate in TEL/AML1+ ALL was similar to that of TEL/AML1- ALL (16.7% [2/12] vs. 20.6% [13/63], p > 0.05). The duration of first complete remission in TEL/AML1+ ALL was significantly longer as compared to TEL/AML1- ALL (mean [range] in month: 48.6 [47.2 - 50] vs 14.6 [2.9 - 42.3], p < 0.0001). Irrespective of TEL/AML1 rearrangement, the probabilities of the five-year overall survival and the event-free survival of patients were comparable (overall survival: 100% vs. 72.3%, p = 0.166 and event-free survival: 60% vs. 56.2%, p = 0.343). Our data would not suggest a less aggressive treatment regimen for TEL/AML1+ ALL. Copyright 2001 Wiley-Liss, Inc.

PMID: 11559948 [PubMed - indexed for MEDLINE]

1: Neoplasma 2000;47(6):382-9 Related Articles, Books, LinkOut

Correlation of clinical picture (event free survival and overall survival) in childhood acute leukemia patients with immunophenotype and chromosomal abnormalities.

Babusikova O, Sejnova D, Kirschnerova G, Kirsnerova Z, Cap J.

Cancer Research Institute, Slovak Academy of Sciences, Bratislava, Slovak Republic. exonobab@savba.sk

In a group of 102 children with different immunological subtypes of acute leukemia, both lymphoblastic and nonlymphoblastic, the clinical parameters - event free survival and overall survival were correlated with numerical and structural chromosomal abnormalities. In a group of 80 ALL patients genetic abnormalities were observed in 40 patients, from those 19 of numerical type, 17 of structural type and 4 with both, numerical and structural anomalies. From the whole ALL group observed 23 patients (28.75%) died. In 10 died patients genetic abnormalities were found and in 6 cases less mature T-phenotype ALL has been documented. It seems, therefore, that immature T-phenotype with pathological karyotypes of all types of genetic anomalies presents the most risk group of patients of which all children died. ALL patients, as a whole, with pathological karyotype have shown significantly lower event free survival rate, comparing to the group of ALL patients with normal karyotype. Overall survival rate was also lower in the first group, but statistically not significant. In T-ALL patients, in both groups, with and without pathological karyotype, event free survival rate and overall survival rate were also lower in the first group, but statistically not significant. In B-ALL patients with pathological karyotypes vs. normal ones overall survival rate was lower in the first group, but statistically not significant. There was no difference in overall survival rate in these patients between pathological and normal karyotypes. In ANNL group of patients pathological karyotype was observed in 14 of them, with numerical anomalies in 6 patients, structural in 4 patients and both of them - numerical + structural in 4 children. From the whole ANLL group observed 11 (50%) patients died during the follow-up period (9 in relapse and 2 of treatment complications). From 11 died patients in 81.8% pathological karyotype was present. The prevalence of pathological karyotypes was observed in less mature M0-M2 ANLL subtype (71.4%). ANLL patients with pathological karyotype have shown significantly lower event free survival rate (in one of the two statistical log-rank analyses), comparing to the group of ANLL patients with normal karyotype. Overall survival rate was also lower in the first group, but statistically not significant. The presence/absence of CD34 marker expression in blast cells of our group of acute leukemia patients did not show any difference in event free survival and overall survival rates.

PMID: 11263863 [PubMed - indexed for MEDLINE]

1: Genes Chromosomes Cancer 2001 Apr;30(4):383-92 Related Articles, Books, LinkOut

Reassessment of childhood B-lineage lymphoblastic leukemia karyotypes using spectral analysis.

Elghezal H, Le Guyader G, Radford-Weiss I, Perot C, Van Den Akker J, Eydoux P, Vekemans M, Romana SP.

Service de Cytogenetique, Hopital Necker-Enfants Malades, Paris, France.

We studied a stratified cohort of 51 childhood B-lineage acute lymphoblastic leukemias (B-ALLs) to evaluate the efficiency of spectral karyotyping (SKY) in the detection of chromosome aberrations previously diagnosed using chromosome banding and/or reverse transcriptase polymerase chain reaction. Despite the small number of cases analyzed, several important features emerge from the study: (a) The result of banding analysis was revised in two-thirds of the cases. Eighty-three chromosome anomalies previously undetected or not characterized using chromosome banding were identified by spectral karyotyping, even in patients with apparently normal karyotypes. (b) All hyperdiploidy cases showed one or more extra copies of chromosomes X, 14, and 21. (c) Two hidden rearrangements, a t(7;12)(?p12;p13), and a new translocation, a t(9;12)(q31;p13), both involving the TEL gene, were characterized. (d) Some cryptic rearrangements, such as the der(21) t(12;21) translocation, remained undetected. (e) No new recurrent chromosome anomalies were discovered with this technique. In conclusion, the present study confirms the efficiency of the SKY technique in resolving and characterizing many complex chromosome anomalies seen in childhood B-ALLs, but it raises questions about the ability of this technique to detect cryptic rearrangements, such as the t(12;21) translocation. Copyright 2001 Wiley-Liss, Inc.

PMID: 11241791 [PubMed - indexed for MEDLINE]

1: Leukemia 2000 Dec;14(12):2307-20 Related Articles, Books, LinkOut

Long-term follow-up of the United Kingdom Medical Research Council protocols for childhood acute lymphoblastic leukaemia, 1980-1997. Medical Research Council Childhood Leukaemia Working Party.

Eden OB, Harrison G, Richards S, Lilleyman JS, Bailey CC, Chessells JM, Hann IM, Hill FG, Gibson BE.

Academic Unit of Paediatric Oncology, Christie and Royal Manchester Children's Hospital NHS Trusts, Oxford, UK.

Results of three consecutive completed UK trials (1980-1997) for childhood lymphoblastic leukaemia are presented. National accrual has progressively increased so that over 90% of all the country's ALL cases were treated on the latest trial reported, UKALLXI. From 1980 to 1990, event-free and overall survival progressively improved, following adoption of an American therapy template and use of two post-remission intensification modules. Since 1990 despite demonstration of the benefit of a third intensification module overall event-free survival (EFS) has not improved further. Survival remains high due to a good retrieval rate especially for those relapsing off treatment after receipt of two intensification pulses. Possible reasons for the plateau in event-free survival (including type and dose of induction steroid, dropping of induction anthracycline, type and dose of asparaginase, gaps early in therapy following intensification, and overall lack of compliance in maintenance) are being explored in the latest protocol ALL '97. Cranial irradiation had been successfully replaced by a long course of intrathecal methotrexate injections for the majority of patients. Age (<1 year >10 years) sex (male) and white count >50 x 10(9)/l plus slow initial bone marrow clearance were consistently the most important independent prognostic indicators during this time period. Rome/NCI criteria accurately predict standard and high-risk groups for B cell lineage, but not consistently for T cell disease. This international collaborative venture might help us to define those truly at highest risk, and how we can optimise therapy for specific subgroups including T-ALL and those with unfavourable cytogenetics.

Publication Types: Clinical Trial Meta-Analysis Randomized Controlled Trial

PMID: 11187922 [PubMed - indexed for MEDLINE]

1: Rinsho Ketsueki 2000 Jul;41(7):576-84 Related Articles, Books, LinkOut

[Prognostic significance of chromosome analysis in childhood acute lymphoblastic leukemia. Children's Cancer and Leukemia Study Group (CCLSG)]

[Article in Japanese]

Hyakuna N, Kaneko Y, Katano N, Iwai T, Nagata T, Sakashita K, Takeda O, Tanaka A, Azuma H, Sekine I, Fujimoto T.

We analyzed the prognostic significance of chromosomal findings in children with acute lymphoblastic leukemia (ALL), treated according to the Children's Cancer and Leukemia Study Group protocols between 1987 and 1993. Patients were classified into 5 groups according to chromosome number. The patients with a hyperdiploid(> 50) karyotype(13%) had the best prognosis [4-year event-free survival (EFS): 83 +/- 6%], while those with a pseudodiploid karyotype (24%) had the worst prognosis(4-year EFS: 52 +/- 6%) (log-rank, p = 0.03). However, multivariate analysis revealed that the ploidy classification had no prognostic significance in terms of EFS. When patients were classified according to chromosome abnormalities, those with any type of translocation had a worse outcome (4-year EFS: 33 +/- 9%) than those with hyperdiploidy(> 50), normal diploidy, and other abnormalities(log-rank, p < 0.0001). Multivariate analysis revealed that chromosome abnormalities were an independent prognostic factor (relative risk 3.98; p < 0.0001). Patients with t(1; 19) had an EFS similar to that of patients with chromosome abnormalities other than translocations or normal diploidy. We conclude that chromosomal findings have prognostic significance, although some chromosome abnormalities lost their statistical significance after modern intensified chemotherapy. Childhood ALL should be further stratified according to chromosome classification.

Publication Types: Clinical Trial Multicenter Study

PMID: 11020981 [PubMed - indexed for MEDLINE]

1: J Formos Med Assoc 2000 Apr;99(4):281-9 Related Articles, Books, LinkOut

Cytogenetic pattern of childhood leukemia in Taiwan.

Yang CP, Wu JH, Hung IJ, Jaing TH.

Department of Medicine, Chang-Gung Children's Hospital, Taoyuan, Taiwan.

BACKGROUND: Cytogenetic analyses of leukemic cells can be used to define specific subgroups of leukemia with different prognoses and, thereby, indicate appropriate treatment for individual cases. In this study, we investigated the cytogenetic pattern of childhood leukemia in Taiwanese patients. METHODS: A modified trypsin method of Seabright was used for G-banding of metaphase cells. RESULTS: From October 1996 to January 1999, 111 children with a diagnosis of leukemia were enrolled in the study. Of these, 73 patients had a diagnosis of acute lymphoblastic leukemia (ALL) and 63 of these patients had successful karyotyping of their leukemic cells. Among them, 20 (30.3%) had a normal karyotype, five had hypodiploidy (all had 45 chromosomes), five had low hyperdiploidy (47-50 chromosomes), 16 (24.2%) had high hyperdiploidy (> 50 chromosomes), and 20 had pseudodiploidy. Chromosomal translocation was identified in 24 (36.4%) of the ALL patients, 17 of whom had recurrent translocations including 10 with CD10+ B-precursor ALL [4 with t(9;22), 5 with t(1;19), and 1 infant with t(8;14)(q24;q11)], one neonate with CD10- early pre-B ALL with t(4;11), three B-cell cases with t(8;14), and three T-cell cases [2 with t(11;19)(q23;p13), and 1 (11;14)(p13;q11)]. One B-precursor patient had dic (9;12). Karyotypes of the 30 patients with acute myeloid leukemia (AML) included eight with t(8;21); seven with the French-American-British-M2 subtype (FAB-M2) and one with M1. All four of the patients with M3 had t(15;17), one patient with M4 had inv(16) and 7q-, one with M4Eo (M4 with eosinophilia) had t(7;16)(q21;q22), one with M0 had t(4;11)(q21;q23), and the remaining 11 had a normal karyotype. Three of the five adult-type chronic myeloid leukemia patients had standard Philadelphia chromosome, and the other two had a variant-form of Philadelphia chromosome. Both of the patients with juvenile myelomonocytic leukemia and one patient with myelodysplastic syndrome had a normal karyotype. CONCLUSIONS: Most findings were similar to previous reports. Although the high proportion of FAB-M2 patients (7/8) with t(8;21) and the consequently higher frequency (26.7%) of this translocation in the 30 AML cases in this study might have significance, a larger series of cases is needed to establish this finding.

PMID: 10870310 [PubMed - indexed for MEDLINE]

1: Adv Exp Med Biol 1999;457:297-303 Related Articles, Books, LinkOut

Apoptosis corrected proliferation fraction in childhood ALL is related to karyotype.

Ball LM, Pyesmany AF, Yhap M, Lannon CL, Henry M, Laybolt K, Riddell DC, van Velzen D.

Department of Pathology, Dalhousie University, IWK Grace Health Centre, Halifax, Nova Scotia, Canada.

BACKGROUND: Tumour doubling time, a parameter in drug sensitivity testing, reflects both cell proliferation and apoptosis. Variable apoptosis fractions may explain the poor correlation of S-fraction and drug response. DNA aneuploidy (reflecting intrinsic DNA instability) may, by increasing apoptosis, affect drug response. AIM: To assess the relationship between apoptosis corrected proliferation fraction and DNA ploidy in childhood acute lymphoblastic leukemia (ALL). METHODS: 1.3.1. Study Groups. Thirty two consecutive, unselected diagnostic cases of childhood ALL were included in the study. 1.3.2. Karyotype. A normal karyotype was found in 15 cases (7M, 8F, age 8 m-12 yrs); high hyperdiploid aneuploidy (DNA index > 1.5) was found in 7 patients (1M, 7F, age 3-12 yrs) whereas complex karyotypic anomalies, but with 2n or near 2n DNA were present in 10 patients (7M, 3F, age 1 y 7 m -16 yrs). 1.3.3. Proliferation Fraction Assessment. Immunocytochemical demonstration of S-phase associated nuclear expression of the Ki-67 antigen (MM1, NovaCastra, UK). 1.3.4. Apoptosis Fraction Assessment. Binding of a horse radish peroxidase labelled DNA probe for the 3'-OH ends of apoptosis derived Klenow fragments (Frag-EL, CalBiochem, USA). 1.3.5. Quantitation. Computer assisted image analysis (Quantimet 570C), of 10 systematically random fields of a minimum of 20 nuclei each. A nuclear size bias correcting counting frame and rule were used to correct for cell proliferation associated nuclear volume increase and for the expected nuclear volume reduction resulting from apoptosis. RESULTS: Corrected for apoptosis, proliferation fraction was highest (mean 57.5%, range 1-100) in poor prognosis, complex karyotype anomalies. Good prognosis, high hyper diploidy showed significantly lower proliferation rates (mean 24.7%, range 12-40) (p < 0.01, t-test). CONCLUSION: Apoptosis corrected cell proliferation rate in childhood ALL is not independent of karyotype abnormality which may partly explain a relation to therapy response and prognosis.

PMID: 10500805 [PubMed - indexed for MEDLINE]

1: Cancer Genet Cytogenet 1999 Apr;110(1):44-53 Related Articles, Books, LinkOut

Clinical significance of cytogenetic findings at diagnosis and in remission in childhood and adult acute lymphoblastic leukemia: experience from India.

Amare P, Gladstone B, Varghese C, Pai S, Advani S.

Department of Medical Oncology, Tata Memorial Hospital, Mumbai, India.

We report cytogenetic findings in 114 patients of acute lymphoblastic leukemia (ALL), which includes 78 children (< or = 15 years) and 36 adults (16-60 years). Chromosome aberrations were detected in 109 (95%) cases. A lower frequency of hyperdiploidy (15%) in children and a higher frequency of hypodiploidy both in children (38.4%) and adults (44.4%) were found, in contrast to literature. Translocations were detected in one third of adult and pediatric cases. The incidence of t(9;22) was comparatively low in adults (7.7%). Frequency of t(1:19) was also low in overall ALL cases. Various other recurrent abnormalities such as del(6q), abn(11q23), i(9p), abn(12q13), del(7q), and i(17q) were seen in our cases; a striking difference in the incidence of del(6q) (41%) and abn(11q23) (30%) was found in our series versus reported literature. Ploidy distribution indicated association of pseudo- and hypodiploidy with B-lineage, and hypodiploidy with T-lineage in children. The occurrence of del(6q) was more frequent in pediatric ALL with highly aberrant pattern and also with lymphadenopathy. Abn(11q23) was found to be early-B and pre-B specific. Kaplan-Meier analysis of overall survival revealed prognostic value of sex, FAB, immunophenotype, and cytogenetic findings. Females and T-ALL patients had a better prognosis, whereas males and B-ALL patients had poor outcome in overall and pediatric age groups. Prognostic evaluation of cytogenetics indicated translocations as an independent high-risk predictor in childhood (P < 0.008) and adult ALL (P < 0.01). Childhood ALL with t(8;14) and t(4;11) and adults with t(9;22) had poor survival. Cytogenetics of remission marrows demonstrated disappearance of abnormal clones in 31.4%, and expansion in normal clones in 50% of patients. Persistence of original clones and development of new clones were observed in 20% and 33% of patients, respectively; whereas karyotype evolution was identified in 10% of patients. The prognostic significance of cytogenetic findings at diagnosis, and differential cytogenetic response in so-called clinical remission in our study indicated the utmost need for more intensive therapy for eradication of resistant clones, and necessity of sequential cytogenetic follow-up in these patients for identification of minimal residual disease.

PMID: 10198622 [PubMed - indexed for MEDLINE]