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Biomedical subjects

A J Carroll

Publications and source records attributed to A J Carroll.

At least 37 records · Page 2Linked to original sources
PubMed1999

Acute lymphoblastic leukemia with the (8;14)(q24;q32) translocation and FAB L3 morphology associated with a B-precursor immunophenotype: the Pediatric Oncology Group experience.

Five pediatric patients are described with acute lymphoblastic leukemia (ALL) who at presentation had clinical findings suggestive of B cell ALL and lymphoblasts with FAB L3 morphology and the characteristic t(8;14)(q24;q32). However, the leukemia cells of all five patients failed to express surface immunoglobulin (sIg) and kappa or lambda light chains. Based on initial immunophenotyping results consistent with B-precursor ALL, four of these cases were initially treated with conventional ALL chemotherapy. These four patients were switched to B cell ALL treatment protocols once cytogenetic results became available revealing the 8;14 translocation. The fifth case was treated with B cell ALL therapy from the outset. Four of the five patients are in complete remission at 64, 36, 29 and 13 months from diagnosis. One patient relapsed and died 6 months after initial presentation. These five unusual cases with clinical B cell ALL, the t(8;14), and FAB L3 morphology, but negative sIg, demonstrate the importance of careful and multidisciplinary evaluation of leukemic cells with morphology, cytochemistry, immunophenotyping and cytogenetic analysis. Future identification of patients with this profile will allow us to expand our knowledge regarding prognostic significance and optimal treatment for this rare subgroup of patients.

Adolescent↗
PubMed1999

Significance of commonly used prognostic factors differs for children with T cell acute lymphocytic leukemia (ALL), as compared to those with B-precursor ALL. A Pediatric Oncology Group (POG) study.

T cell acute lymphocytic leukemia (T-ALL) and B-precursor ALL differ significantly in the clinical characteristics of the patients at presentation and in laboratory-defined characteristics of the leukemic cells. We assessed for pediatric patients with T-ALL the relative importance of prognostic factors previously demonstrated to predict outcome in B-precursor ALL. Presenting clinical and laboratory features were correlated with outcome for 441 children 12 months to 21 years of age with previously untreated T-ALL, registered on the Pediatric Oncology Group (POG) T3 protocol between 1986 and 1992. These T-ALL prognostic factor analyses were then compared to similar analyses for 1993 patients with B-precursor ALL enrolled during the same time period on the POG ALinC 14 protocol. Quantitative interaction between phenotype and each prognostic factor was studied to determine the relative importance of the prognostic factor for each of the two major immunophenotypes. We also analyzed the importance of maturational stage as a T-ALL prognostic factor, using a modified Ludwig definition of maturational stage. We conclude that several of the clinical and laboratory prognostic factors, which are used reliably for B-precursor ALL, are much less predictive in T-ALL (ie age, WBC, consensus risk group, hyperdiploidy, presence of trans- locations and CALLA expression). There was no significant difference between the phenotypes in the prognostic importance of race or gender. Our data demonstrate a significant difference in outcome among the three maturational stages of T-cell ALL, with the intermediate group faring best. Using traditional risk group criteria to stratify patients with T-ALL for therapy may not be appropriate.

Adolescent↗
PubMed1999

p27KIP1 deletions in childhood acute lymphoblastic leukemia.

The p27KIP1 gene, which encodes a cyclin-dependent kinase (CDK) inhibitor, has been assigned to chromosome band 12p12, a region often affected by cytogenetically apparent deletions or translocations in childhood acute lymphoblastic leukemia (ALL). As described here, fluorescence in situ hybridization (FISH) analysis of 35 primary ALL samples with cytogenetic evidence of 12p abnormalities revealed hemizygous deletions of p27KIP1 in 29 cases. Further analysis of 19 of these cases with two additional gene-specific probes from the 12p region (hematopoietic cell phosphatase, HCP and cyclin D2, CCND2) showed that p27KIP1 is located more proximally on the short arm of chromosome 12 and is deleted more frequently than either HCP or CCND2. Of 16 of these cases with hemizygous deletion of p27KIP1, only eight showed loss of HCP or CCND2, whereas loss of either of the latter two loci was uniformly associated with loss of p27KIP1. Missense mutations or mutations leading to premature termination codons were not detected in the coding sequences of the retained p27KIP1 alleles in any of the 16 ALL cases examined, indicating a lack of homozygous inactivation. By Southern blot analysis, one case of primary T-cell ALL had hemizygous loss of a single p27KIP1 allele and a 34.5-kb deletion, including the second coding exon of the other allele. Despite homozygous inactivation of p27KP1 in this case, our data suggest that haploinsufficiency for p27KIP1 is the primary consequence of 12p chromosomal deletions in childhood ALL. The oncogenic role of reduced, but not absent, levels of p27KIP1 is supported by recent studies in murine models and evidence that this protein not only inhibits the activity of complexes containing CDK2 and cyclin E, but also promotes the assembly and catalytic activity of CDK4 or CDK6 in complexes with cyclin D.

Adolescent↗
PubMed1999

Childhood acute lymphoblastic leukemia with the MLL-ENL fusion and t(11;19)(q23;p13.3) translocation.

PURPOSE: To determine the molecular characteristics, clinical features, and treatment outcomes of children with acute lymphoblastic leukemia (ALL) and the t(11;19)(q23,p13.3) translocation. PATIENTS AND METHODS: A retrospective analysis of leukemic cell karyotypes obtained from patients with new diagnoses of ALL who were treated at St. Jude Children's Research Hospital or by the Pediatric Oncology Group was performed to identify cases with the t(11;19)(q23;p13.3) translocation. Molecular analyses were performed on these cases to determine the status of the MLL gene and the presence of the MLL-ENL fusion transcript. RESULTS: Among 3,578 patients with ALL and successful cytogenetic analysis, we identified 35 patients with the t(11;19)(q23;p13.3) translocation: 13 infants and 11 older children had B-precursor leukemia, whereas 11 patients had a T-cell phenotype. Although all of the cases examined had MLL rearrangements and MLL-ENL fusion transcripts, outcome varied according to age and immunophenotype. Among B-precursor cases, only two of the 13 infants remain in complete remission, compared with six of the 11 older children. Most strikingly, no relapses have occurred among B-precursor patients 1 to 9 years of age or among T-cell patients. CONCLUSION: Although MLL gene rearrangements are generally associated with a dismal outcome in ALL, two distinct subsets with MLL-ENL fusions have an excellent prognosis. Our results suggest that patients with this genetic abnormality who have T-cell ALL or are 1 to 9 years of age should not be considered candidates for hematopoietic stem-cell transplantation during their first remission.

Adolescent↗
PubMed1998

Chromosome 18q paracentric inversion in a family with mental retardation and hearing loss.

We report on a mother and child with a paracentric inversion of the long arm of chromosome 18: 46,XX,inv(18)(q21.1q23). The child had findings in common with those seen in 18q- syndrome including: microcephaly, epicanthal folds, midface hypoplasia, and abnormally modeled ears, dermatoglyphic whorls on fingertips, clubfeet, hearing loss, and developmental delay. The mother and several maternal relatives had mild mental retardation and hearing loss. Magnetic resonance imaging of the child's brain showed abnormal myelination. Molecular studies including PCR-based markers for the MBP locus and fluorescent in situ hybridization with a P1 genomic clone on mother and child demonstrated only one copy of the MBP locus (18q23) with the deletion extending beyond the MBP locus. Therefore, the deletion in the MBP region may account for the abnormal myelination seen in the patient. The other clinical findings, including mental retardation and hearing loss in this family, may reflect disruption of distal or proximal genes within the deleted MBP region or at the more proximal breakpoint 18q21.1, and may represent a contiguous gene syndrome. Further study of this family may help define those genes functioning in the MBP region that contribute to the phenotype of 18q- syndrome.

Adult↗
PubMed1998

E2A-PBX1 chimeric transcript status at end of consolidation is not predictive of treatment outcome in childhood acute lymphoblastic leukemias with a t(1;19)(q23;p13): a Pediatric Oncology Group study.

A t(1;19)(q23;p13) is detected cytogenetically in approximately 5% of childhood acute lymphoblastic leukemias (ALLs) and its presence has been associated with an increased risk of relapse in several previously-completed Pediatric Oncology Group (POG) clinical trials. The t(1;19) fuses E2A to PBX1 in more than 95% of cases and this molecular abnormality can be reliably identified by polymerase chain reaction (PCR)-mediated amplification of E2A-PBX1 chimeric mRNAs. We used a nested PCR assay, which reproducibly detected a 10(4)- to 10(5)-fold dilution of t(1;19)+ into t(1;19)- cells, to evaluate minimal residual disease (MRD) in 48 children with t(1;19)+ ALL enrolled in POG clinical trials for lower (POG 9005) and higher (POG 9006) risk ALL. Peripheral blood (PB) and bone marrow (BM) samples were collected prospectively at the end of consolidation (weeks 25 and 31 after end of induction) and the presence or absence of PCR-detectable MRD was correlated with clinical outcome. Overall, 41 of 148 (28%) samples were PCR+. Of the 65 time points with informative results from both PB and BM, PCR results were concordant for 51 pairs (10 PB+/BM+, 41 PB-/ BM-) and discordant for 14 (5 PB+/BM-, 9 PB-/BM+), indicating that assessment of only PB or only BM can inaccurately classify some PCR+ cases as PCR-. There were no significant differences in event-free survival between PCR+ and PCR- patients. We conclude that qualitative detection of MRD by amplification of E2A-PBX1 chimeric mRNAs at the end of consolidation was not significantly predictive of outcome for children treated on POG 9005/9006 and that such results should not be used to alter therapy for patients with t(1;19)+ ALL.

Antineoplastic Combined Chemotherapy Protocols↗
PubMed1998

Prevalence of myeloperoxidase gene expression in infant acute lymphocytic leukemia.

The enzyme myeloperoxidase (MPO; donor: H2O2 oxidoreductase, EC1.11.1.7) is a well-established marker of myeloid differentiation. Most myeloid leukemias express MPO enzyme activity at the light microscopic level, whereas lymphoid leukemias characteristically lack such expression. However, the diagnostic significance of MPO RNA expression or of immunohistochemically detectable MPO protein expression in leukemic blasts is unclear. We studied the prevalence and diagnostic significance of MPO RNA and protein expression in 57 cases of MPO enzyme-negative infant B-precursor acute lymphocytic leukemia (ALL), since the blast cells in this condition have been reported to show a high incidence of coexpression of myeloid-associated antigens. MPO expression was compared with other clinical and laboratory parameters. Of the cases examined, 56% showed detectable MPO expression at the RNA or protein level or both. Most positive cases showed MPO protein in many leukemic blasts, whereas a few cases showed substantial MPO protein expression in only a few blast cells. MPO expression showed no significant correlation with other markers of myeloid differentiation. Leukemic lymphoblasts in infant ALL frequently express MPO at the RNA or protein level; this expression does not imply an overall myeloid phenotype. The leukemic blasts in infant ALL may derive from an immature hematopoietic precursor cell not fully committed to lymphoid differentiation.

Blotting, Northern↗
PubMed1998

Consolidation therapy with antimetabolite-based therapy in standard-risk acute lymphocytic leukemia of childhood: a Pediatric Oncology Group Study.

PURPOSE: To develop antimetabolite-based consolidation regimens that minimize acute and long-term toxicities and improve the survival rate of children with standard-risk B-lineage acute lymphocytic leukemia (ALL). PATIENTS AND METHODS: Seven hundred twenty-seven eligible patients with standard-risk early pre-B ALL were registered onto the study. Seven hundred sixteen patients attained a complete remission (CR) after induction therapy. Of these, 114 patients were randomized to a different regimen and were the subject of a separate report. Six hundred two patients were randomized to receive one the following regimens: intermediate-dose methotrexate (IDMTX) with leucovorin rescue on weeks 7, 10, 13, 16, 19, and 22 (regimen A); regimen A plus asparaginase (ASP) administered intramuscularly (i.m.) weekly for 24 weeks (regimen B); or regimen A plus a 24-hour infusion of cytarabine (AraC) with each IDMTX (regimen C). After consolidation, patients were placed on maintenance therapy through week 156. Regimens A and C were opened in February 1986, and regimen B in May 1987. Comparisons are based on concurrently randomized patients (May 1987 to January 1991 between regimens A and B, and February 1986 to January 1991 between regimens A and C). RESULTS: The 5-year continuous CR (CCR) rates were not significantly different: A versus B, 78.1% (3.9 +/- SE) versus 83.3% +/- 3.5% and A versus C, 79.4% +/- 3.2% versus 83.5% +/- 2.9%; P by one-sided log-rank tests were .27 and .34, respectively. Significant treatment differences were not found with regard to sex, rate of testicular and CNS relapse, or CNS complications. During consolidation, regimen C had significantly more bacterial infections (P = .0032) and days spent in the hospital (P < .001) compared with regimen A. CONCLUSION: We were unable to show a statistical advantage of adding either ASP or AraC to IDMTX in terms of improvement in event-free survival (EFS).

Antimetabolites, Antineoplastic↗
PubMed1998

Prognostic significance of sex in childhood B-precursor acute lymphoblastic leukemia: a Pediatric Oncology Group Study.

PURPOSE: In childhood B-precursor acute lymphoblastic leukemia (ALL), possible interactions among sex, time, and widely used prognostic factors (age, WBC count, and DNA index) were investigated for the first 5 years after diagnosis. PATIENTS AND METHODS: All eligible patients aged 1 to less than 22 years, registered between February 1986 and September 1994 in two B-precursor ALL studies from the Pediatric Oncology Group (POG), were included in the analysis. Cutpoints for age (3.0, 5.0, and 10.0 years), WBC count (10, 50, and 100 x 10(9)/L), and DNA index (DI; 1.16) were defined. Four time periods after diagnosis (years 1, 2, 3, and 4 and 5 combined) were selected for the study of prognostic significance over time. The cut-off date for analysis was April 1996. RESULTS: A total of 3,717 children (2,010 boys and 1,707 girls) were included in the outcome analysis. No major differences between the sexes were observed in age, duration of symptoms before registration, WBC count, hemoglobin level, platelet count, ploidy, presence of CNS disease at diagnosis, or induction failure rate. Event-free survival (EFS) differences between sexes became significantly different from 2 years following diagnosis. At 5 years, in all subsets analyzed, boys fared worse than girls, although not all differences were statistically significant. Major sex differences in EFS were observed in older children (10 to 22 years), in patients with intermediate WBC counts (10 to 50 x 10(9)/ L), and in children who fit both of these subgroups, in whom the 2-year EFS was almost 20% higher in girls than in boys, reaching a 38% difference at 5 years. CONCLUSION: This study shows an outcome interaction among sex, time, and commonly used prognostic variables. The important sex difference observed at 2 and 5 years suggests that more intensive consolidation and/or maintenance therapy in some boys with B-precursor ALL should be investigated.

Adolescent↗
PubMed1998

Myeloperoxidase gene expression in infant leukemia: a Pediatric Oncology Group Study.

A high incidence of co-expression of myeloid-associated antigens in infant B-precursor Acute Lymphocytic Leukemia (B-ALL) has been reported, but the significance of this finding is uncertain. To further assess myeloid differentiation and its prognostic significance in this disease, we investigated the frequency of myeloperoxidase (MPO) gene expression in the blast cells from 43 infants with B-ALL registered in a Pediatric Oncology Group (POG) Pilot Study for Treatment of Infant ALL, utilizing a molecular probe for detection of MPO messenger RNA (mRNA) by Northern blot hybridization and a monoclonal antibody to detect MPO-protein by immunohistochemical staining. Sufficient RNA for Northern blot was extracted from 32 bone marrow or blood samples. In two cases, MPO mRNA was determined by a reverse transcriptase-polymerase chain reaction assay and was negative in both cases. MPO-specific transcripts (MPO+) were present in 19 of 34 (56%) samples analyzed. Immunoreactive MPO protein was positive in 13 of the 20 (65%) patients studied. No correlation was found between MPO gene expression and clinical or laboratory features, karyotypic patterns or clinical outcome. The high frequency of MPO gene expression demonstrated in this study suggests that leukemogenic events in many cases of infant B-ALL appear to involve a pluripotent stem cell not yet fully committed to lymphoid differentiation.

Antibodies, Monoclonal↗
PubMed1997

Adult patients with de novo acute myeloid leukemia and t(9; 11)(p22; q23) have a superior outcome to patients with other translocations involving band 11q23: a cancer and leukemia group B study.

Following reports of childhood acute myeloid leukemia (AML) showing that patients with t(9; 11)(p22; q23) have a better prognosis than those with translocations between 11q23 and other chromosomes, we compared response to therapy and survival of 24 adult de novo AML patients with t(9; 11) with those of 23 patients with other 11q23 translocations [t(11q23)]. Apart from a higher proportion of French-American-British (FAB) M5 subtype in the t(9; 11) group (83% v 43%, P = .006), the patients with t(9; 11) did not differ significantly from patients with t(11q23) in terms of their presenting clinical or hematologic features. Patients with t(9; 11) more frequently had an extra chromosome(s) 8 or 8q as secondary abnormalities (46% v 9%, P = .008). All patients received standard cytarabine and daunorubicin induction therapy, and most of them also received cytarabine-based intensification treatment. Two patients, both with t(9; 11), underwent bone marrow transplantation (BMT) in first complete remission (CR). Nineteen patients (79%) with t(9; 11) and 13 (57%) with t(11q23) achieved a CR (P = .13). The clinical outcome of patients with t(9; 11) was significantly better: the median CR duration was 10.7 versus 8.9 months (P = .02), median event-free survival was 6.2 versus 2.2 months (P = .009), and median survival was 13.2 versus 7.7 months (P = .009). All patients with t(11q23) have died, whereas seven (29%) patients with t(9; 11) remain alive in first CR. Seven of eight patients with t(9; 11) who received postremission regimens with cytarabine at a dose of 100 (four patients) or 400 mg/m2 (2 patients) or who did not receive postremission therapy (2 patients) have relapsed. In contrast, 7 (64%) of 11 patients who received intensive postremission chemotherapy with high-dose cytarabine (at a dose 3 g/m2) (5 patients), or underwent BMT (2 patients) remain in continuous CR. We conclude that the outcome of adults with de novo AML and t(9; 11) is more favorable than that of adults with other 11q23 translocations; this is especially true for t(9; 11) patients who receive intensive postremission therapy.

Acute Disease↗
PubMed1997

Prognostic significance of fluorescence intensity of surface marker expression in childhood B-precursor acute lymphoblastic leukemia. A Pediatric Oncology Group Study.

This report describes the prognostic significance of the intensity of surface membrane antigen expression in a series of 1,231 children older than 1 year with newly diagnosed B-precursor acute lymphoblastic leukemia (ALL) treated on Pediatric Oncology Group (POG) treatment protocols. All patients had dual-color flow cytometric immunophenotyping performed at a central reference laboratory with a standard panel of monoclonal antibodies. The flow cytometers used in the study were calibrated with a standard fluorescence microparticle that permitted conversion of relative fluorescence channels to standard units of mean equivalents of soluble fluorochrome (MESF). In univariate analysis, fluorescence intensity of CD45 and CD20 was significantly associated with event-free survival (EFS), whereas other markers showed no significant correlation with outcome. Patients whose blasts were greater than the 75th percentile of intensity for CD45 (corresponding to 18,000 MESF units with CD45-FITC, or about 8% of the intensity of normal lymphocytes) fared significantly worse than those with lower-density CD45, and those whose blasts were greater than the 25th percentile of intensity for CD20 (corresponding to 17,900 MESF units with CD20-PE) had a poorer EFS. The intensity of both CD45 and CD20 was independently correlated with outcome. There was no significant correlation between intensity of expression of either antigen and traditional clinical risk factors, ploidy, or t(9;22) or t(1;19). All patients with t(4;11) had CD45 intensity greater than the 75th percentile, but CD45 intensity retained its prognostic significance after adjusting for t(4;11). In multivariate analysis, both CD45 intensity greater than the 75th percentile and CD20 intensity greater than the 25th percentile were significantly correlated with poor outcome independently of previously reported poor prognostic factors including National Cancer Institute (NCI) risk group, ploidy, trisomies of 4 and 10, and adverse translocations including t(1;19), t(9;22), and t(4;11). We conclude that in childhood B-precursor ALL, the intensity of expression of CD20 and CD45 provides prognostic information not available from simple consideration of antigen expression as positive or negative, and adds to that obtained from traditional clinical and biologic risk factors.

Adolescent↗
PubMed1997

Hyperdiploidy and E2A-PBX1 fusion in an adult with t(1;19)+ acute lymphoblastic leukemia: case report and review of the literature.

The t(1;19)(q23;p13), detected cytogenetically in 5-6% of cases, is one of the most common translocations in childhood acute lymphoblastic leukemia (ALL). Most t(1;19)+ ALLs are pseudodiploid or contain fewer than 50 chromosomes, are classified as pre-B based on expression of cytoplasmic, but not surface, immunoglobulin (clg+/slg-), express a characteristic pattern of cell surface antigens, and contain E2A-PBX1 fusion mRNAs. A minority of cases are early pre-B (clg-/slg-), do not express the characteristic pattern of cell surface antigens, and lack E2A-PBX1 fusion mRNAs. These latter cases are frequently hyperdiploid, with a modal chromosome number of 55-57. The incidence of the t(1;19) in adults with ALL (approximately 3%) appears to be similar to that observed in children, but the genetic and immunophenotypic features of adult t(1;19)+ ALL have not been described extensively. We report a case of t(1;19)+ ALL occurring in a 38-year-old man in the setting of hyperdiploidy > 50. Despite this feature, this case was pre-B, conformed to the classic t(1;19) immunophenotype, and expressed E2A-PBX1 fusion mRNAs. This prompted us to review the published literature on ploidy and genetic features of t(1;19)+ ALLs. Overall, E2A-PBX1 fusion occurred in 95% (102/107) of t(1;19)+ B-lineage ALLs with 50 or fewer chromosomes, 80% of which were pseudodiploid, vs. only 25% (2/8) of t(1;19)+ ALLs with more than 50 chromosomes.

Adult↗
PubMed1997

Identification of a recombination event narrowing the Lafora disease gene region.

Patients affected with progressive myoclonus epilepsy of the Lafora type present during late adolescence with a characteristic EEG pattern and Lafora bodies seen on skin biopsy. The critical region for the Lafora gene has been localised to chromosome 6q24 flanked by the dinucleotide repeat markers D6S292 and D6S420. This study for linkage of markers from the candidate gene region was performed in a previously unpublished family affected with Lafora disease. EEG and skin biopsy evaluation for Lafora bodies were performed on five of eight family members followed for seizure activity. Haplotype and linkage analysis of DNA from five family members were carried out using the nine dinucleotide repeat markers reported in the common region of homozygosity by Serratosa et al in 1995. The present study of an additional family affected by Lafora disease has narrowed the 17 cM critical region for the Lafora disease gene on chromosome 6q24 to a 4 cM region flanked by markers D6S308 and D6S311.

Chromosome Banding↗
PubMed1997

Extramedullary leukemia adversely affects hematologic complete remission rate and overall survival in patients with t(8;21)(q22;q22): results from Cancer and Leukemia Group B 8461.

PURPOSE: To examine the prognostic significance of extramedullary leukemia (EML) at presentation in patients with t(8;21)(q22;q22) karyotype. PATIENTS AND METHODS: Consecutive patients with t(8;21) treated on Cancer and Leukemia Group B de novo acute myeloid leukemia (AML) treatment studies were examined for the presence of EML (granulocytic sarcoma, subcutaneous nodules, leukemia cutis, or meningeal leukemia) at initial presentation. Clinical features and outcome of t(8;21) patients with and without EML were compared. RESULTS: Of 84 patients with t(8;21), eight (9.5%) had EML manifesting as granulocytic sarcoma (five paraspinal, one breast, and one subcutaneous) or symptomatic meningeal leukemia (n = 1). The pretreatment prognostic variables of t(8;21) patients with and without EML were similar. The hematologic complete remission (CR) rate for t(8;21) patients with EML was 50% versus 92% for those without EML (P=.006). The median CR duration for EML patients was 14.7 months. Patients with EML had a shorter survival (P = 0.002, median 5.4 months versus 59.5 months). This poor outcome may relate to inadequate local (radiation or intrathecal) therapy for patients with spinal or meningeal EML, resulting in residual/recurrent EML following induction chemotherapy (n = 2) or at relapse (n = 1) and permanent neurologic deficits (n = 4). Only one of the EML patients received high-dose cytarabine (HDAC) intensification; this is the only EML patient remaining alive in CR. CONCLUSION: Patients with t(8;21) and EML have a low CR rate and overall survival. An aggressive local and systemic induction therapy should be considered for this patient subset. The effectiveness of HDAC intensification in t(8;21) patients with EML is uncertain and warrants further study.

Adult↗
PubMed1997

Secondary cytogenetic changes in acute promyelocytic leukemia--prognostic importance in patients treated with chemotherapy alone and association with the intron 3 breakpoint of the PML gene: a Cancer and Leukemia Group B study.

PURPOSE: To examine, in newly diagnosed patients with acute promyelocytic leukemia (APL), the prognostic significance of secondary cytogenetic changes and the relationship between such changes and the two major promyelocytic leukemia-retinoic acid receptor alpha (PML-RAR alpha) mRNA types. PATIENTS AND METHODS: One hundred sixty-one patients with t(15;17)(q22;q11-12) enrolled onto Cancer and Leukemia Group B (CALGB) protocol 8461, a prospective study of cytogenetics in acute myeloid leukemia (AML), were studied. Eighty of these 161 patients were treated solely with chemotherapy and evaluated for response to treatment and survival. PML-RAR alpha mRNA type was determined using reverse transcriptase polymerase chain reaction (RT-PCR) in 56 patients. RESULTS: The incidence of secondary cytogenetic abnormalities was 32%. Among 80 patients treated with chemotherapy, the presence of a secondary chromosome abnormality was associated with longer complete remission (CR) duration (median, 29.9 v 15.7 months; P = .03) and longer event-free survival (EFS) duration (median, 17.0 v 12.2 months; P = .03). There was no difference in overall survival (P = .28). In a separate group of 56 patients with both cytogenetic and molecular data, 32 had the type L PML-RAR alpha transcript (intron 6 PML breakpoint). Of these 32 patients, four (12.5%) had chromosome changes in addition to t(15;17), whereas 12 of 20 patients (60%) with the type 5 PML-RAR alpha transcript (intron 3 PML breakpoint) had secondary cytogenetic changes (P < .001). CONCLUSION: (1) Secondary cytogenetic changes do not confer a poor prognosis in APL patients treated with anthracycline/cytarabine (Ara-C)-based chemotherapy; and (2) A highly significant relationship exists between the PML-RAR alpha 5 isoform (intron 3 PML genomic breakpoint) and secondary cytogenetic changes in APL.

Adolescent↗
PubMed1996

Molecular analysis of t(11;19) breakpoints in childhood acute leukemias.

MLL is fused to ENL or ELL in acute leukemias that contain t(ll;19)(q23;p13). Although ENL and ELL localize to chromosome 19, bands p13.3 and p13.1, respectively, these breakpoints are not always readily distinguished by standard cytogenetics. We therefore used reverse transcriptase-polymerase chain reaction (RT-PCR) assays to analyze 26 cases of childhood acute leukemia containing t(11;19) to determine the frequencies of ENL and ELL involvement. All 17 cases of acute lymphoblastic leukemia (ALL) had MLL/ENL fusion transcripts. By contrast, of the 9 cases of acute myeloid leukemia (AML) analyzed, 6 had MLL/ENL fusions, 2 had MLL/ELL fusions, and 1 case had no RT-PCR-detectable MLL fusion mRNA. These data suggest that the majority of 11;19 translocations involve ENL, whereas involvement of ELL is relatively uncommon in childhood acute leukemia and may be restricted to AML.

Acute Disease↗