Low frequency of TEL/AML1 in adult acute lymphoblastic leukemia

Translocation (12;21)(p13;q22) is a recently characterized aberration in acute lymphoblastic leukemia, and results in the fusion of the TEL and the AML1 genes. It is the most common translocation in pediatric acute lymphoblastic leukemia (ALL), occurring in about one third of the cases. To determine the frequency of TEL/AML1 in adult ALL, we studied 4 cases of T lineage ALL and 26 cases of B lineage ALL. Only one positive case was identified, giving a very low frequency of 3.3%. In this patient, TEL/AML1 was still detectable in complete hematologic remission. The apparent age predilection of t(12;21) warrants further investigations.     

Surface antigen phenotype can predict TEL-AML1 rearrangement in childhood B-precursor ALL: a Pediatric Oncology Group study

The t(12;21)(p13;q22) is the most common translocation in childhood B-precursor ALL. It results in a TEL-AML1 rearrangement and is associated with a good prognosis. Because many chromosomal alterations in leukemia are associated with distinct cell surface phenotypes, we investigated whether there was an association seen between surface marker expression and the TEL-AML1 rearrangement. Of 166 unselected cases of B-precursor ALL studied by Southern hybridization, 45 cases (27%) showed TEL rearrangement. Blasts of patients with TEL rearrangement were much more likely to be CD9-negative, CD45-positive, CD13 positive, and CD20 negative, but the predictive value of any of these markers for the rearrangement was very low. However, 93% of patients with the TEL rearrangement had blasts that were either negative or only partly positive for CD9; this phenotype was only seen in 27% of patients without the rearrangement. Only information about CD20 expression added to the predictive value of CD9 alone. The predictive value of the phenotype CD9 (negative or partly positive) and CD20 (negative or partly positive), for the TEL rearrangement was prospectively tested on an additional 223 cases, and found to be 88% sensitive and 71% specific for the rearrangement, with a positive predictive value of 47%. Hyperdiploidy, previously shown to correlate negatively with the rearrangement, was a slightly more sensitive indicator (94%) but had a much lower predictive value (28%). Three of eight cases found to be rearranged by Southern hybridization but lacking the characteristic phenotype failed to show evidence of the TEL-AML1 rearrangement by polymerase chain reaction, suggesting that at least some of the discordant cases may involve partner genes other than AML1 in the TEL rearrangement. We conclude that immunophenotyping is highly predictive of the TEL rearrangement. For every 100 patients with B-precursor ALL, we estimate that prescreening by phenotyping would eliminate the need for molecular testing on 57 patients and only two or three of an expected 24 patients with the TEL rearrangement would not be detected.     

Phenotypic conversion from t(8;21) acute myeloid leukemia to MLL gene rearrangement-positive acute lymphoblastic leukemia

Phenotypic conversion from acute myeloid leukemia (AML) to acute lymphoblastic leukemia (ALL) is rare. A 38-year-old man was initially diagnosed as having AML (FAB-M2) associated with the t(8;21)(q22;q22) chromosomal abnormality. The blasts showed myeloperoxidase (MPO) activity and CD13 antigen expression. He showed complete remission after standard chemotherapy for AML. However, the patient relapsed with blasts showing ALL morphology (FAB-L1), MPO negativity, and CD19 antigen expression 33 months after cessation of AML therapy. Cytogenetic analysis at relapse was unsuccessful. Molecular analysis of ALL blasts revealed immunoglobulin heavy-chain gene and MLL gene rearrangements but no AML1 gene. MLL gene rearrangement or the 11q23 chromosomal abnormality has been associated with therapy-related leukemia. The subsequent ALL in our patient may have been induced by the chemotherapy including daunorubicin, known as a topoisomerase II inhibitor.     

Second allogeneic bone marrow transplantation in acute leukemia: a multicenter study from the Gruppo Italiano Trapianto Di Midollo Osseo (GITMO)

Thirty-eight second allogeneic bone marrow transplants (BMT) for acute leukemia relapsed after first BMT were performed in 13 Italian centers between 1987 and 1994. Twenty-one patients had acute myelogenous leukemia (AML), 17 acute lymphoblastic leukemia (ALL); at second BMT 24 patients were in complete remission (CR) and 14 in relapse. The median time to relapse after first BMT was 10 months (range 1-70). Grade II or greater acute graft-versus-host disease (GVHD) after second transplant occurred in 34.2% of patients and a chronic GVHD in 31.5% of patients. Twenty-four patients died: seven from early transplant-related mortality (TRM), 13 from relapse and four from late toxicity. As of 31 July 1996, at a median follow-up of 47 months (range 22-85), there are 14 survivors. The three-year probability of TRM, relapse and event-free survival (EFS) is 28%, 40% and 42% respectively. In 20 of 27 evaluable patients, remission duration after second BMT was longer than after the first BMT. A diagnosis of AML was correlated with a better outcome. These data support the usefulness of second allograft in selected patients with AML relapsing after a first BMT.     

The role of thiotepa in autologous bone marrow transplantation for acute leukemia

Post-transplant leukemic relapse remains the major problem following autologous bone marrow transplantation (ABMT). One possible approach to reducing the relapse rate is to intensify pre-transplant conditioning. Thiotepa (TTP) is an alkylating agent that has been used mainly in breast and ovarian cancer with 20-50% response rates. This report presents our results on 33 patients with acute leukemia (acute myeloblastic leukemia (AML) 27 patients, acute lymphoblastic leukemia (ALL) six patients) who underwent ABMT following conditioning with busulfan (BU), 4 mg/kg x 4 days (days -8 to -5), TTP 5 mg/kg x 2 days (days -4, -3) and cyclophosphamide (CY) 60 mg/kg x 2 days (days -2, -1). Of the 33 patients, 22 were males and 11 females, of median age 24 (1-55) years. Twenty-eight patients were transplanted in complete remission (AML 26; ALL 2) while 5 (AML 1; ALL 4) were in early relapse. Twenty-nine additional AML patients (15 females, 14 males) of median age 22 (2-48) years, who underwent ABMT following a standard BU-CY conditioning regimen (25 in complete remission and four in relapse) served as historical controls. There were no significant differences between the study and control groups with respect to patient age, sex, diagnosis, stage of disease, FAB classification, and prior chemotherapy, at ABMT. Overall survival, disease free survival (DFS), and relapse rate at 72 months were 33, 33 and 61%, respectively, for the study group, and 38, 34.5 and 52%, respectively, for the historical controls. Engraftment and transplant related toxicity also did not differ significantly in the two groups. In conclusion, TTP appears to have made no substantial improvement to the outcome of ABMT for acute leukemia.     

MLL gene rearrangement, cytogenetic 11q23 abnormalities, and expression of the NG2 molecule in infant acute myeloid leukemia

To study prognostic factors in infant acute myeloid leukemia (AML), we analyzed 44 children treated on Childrens Cancer Group protocols for MLL gene rearrangement by Southern blot, cytogenetic 11q23 abnormalities, and reactivity with monoclonal antibody 7.1. This antibody detects the human homologue of the rat NG2 chondroitin sulfate proteoglycan molecule, which has previously been reported to be expressed on human melanoma. NG2 has been found to be expressed on human leukemic blasts but not on other hematopoietic cells. In childhood AML, NG2 cell surface expression correlated with poor outcome and with some but not all 11q23 rearrangements. In childhood acute lymphoblastic leukemia, NG2 expression correlated with poor outcome and with balanced 11q23 translocations. In this study, 29 of 44 (66%) of infants with AML showed MLL rearrangement and, as expected, this group had a high incidence of French-American-British M4/M5 morphology (22/29). Of the cases tested, 35.1% (13/37) were NG2 positive. All (13/13) NG2-positive cases were rearranged at MLL, whereas only 46% (11/24) of NG2-negative cases had MLL rearrangement. NG2 expression did not correlate with poor outcome (P = .31); there was a trend towards a worse outcome with MLL rearrangement (P = .13). Thus monoclonal antibody 7.1 does not detect all cases of MLL rearrangement in infant AML.     

Prognostic factors in the acute lymphoid and myeloid leukemias of infants

The age boundaries and prognostic factors that define the infant leukemias are still controversial. We therefore analyzed event-free survival according to age group in 96 children treated for acute lymphoblastic leukemia (ALL) and 51 treated for acute myeloid leukemia (AML) before the age of 2 years. The study population was registered in consecutive institutional trials of multiagent chemotherapy conducted between 1980 and 1994. Among infants with ALL, event-free survival was significantly poorer in the 0- to 6-month-old group than in patients treated between 6 and 12 months of age (P = 0.03), whose outcome was in turn inferior to that in the 12- to 18-month and 18- to 24-month age groups (P = 0.013). Leukemic cells from ALL patients younger than 12 months had a significantly higher frequency of 11q23/MLL abnormalities, as well as better growth in stromal cell culture, compared to lymphoblasts from the older groups (P < 0.01). The only independent predictor of adverse prognosis among infants diagnosed with ALL before age 12 months was the presence of an 11q23/MLL rearrangement (P = 0.03). These findings contrast sharply with results for the AML cohort, whose event-free survival did not vary significantly by age group (P = 0.58). Male sex (P = 0.01) and leukocyte count > or = 50 x 10(9/l) (P = 0.04), but not 11q23 abnormalities, were independently associated with a poorer outcome for children with AML younger than 12 months at diagnosis. Thus, in very young children with ALL (but not AML), the rearrangement status of the 11q23/MLL region supersedes age group as a determinant of treatment outcome.     

Residual disease detection using fluorescent polymerase chain reaction at 20 weeks of therapy predicts clinical outcome in childhood acute lymphoblastic leukemia

PURPOSE: Ninety-five percent of children with acute lymphoblastic leukemia (ALL) will achieve a remission, but approximately 25% will relapse. Identifying these patients is difficult, as patients with adverse prognostic features at presentation are rare and the majority are standard risk. Analysis of minimal residual disease (MRD) may be able to determine those at risk of relapse, but the best method by which this can be accomplished has yet to be defined. The object of this study was to determine the predictive value of residual disease detection in a group of standard-risk patients with precursor-B ALL at a fixed point in therapy (week 20) using a simple fluorescent consensus immunoglobulin H (IgH) heavy chain polymerase chain reaction (PCR). PATIENTS AND METHODS: Forty-two patients who presented with precursor-B ALL with standard-risk clinical features and treated according to either the Medical Research Council (MRC) UKALL X or XI protocols were assessed using a combination of both fluorescent consensus framework I and framework III Ig heavy-chain PCR. The results of the PCR were analyzed on an ABI 373 gene sequencer with genescan software (Applied Biosystems, Foster City, CA). Clonal rearrangements detected at presentation were looked for at week 20. RESULTS: Of 42 patients, 35 had a clonal population detectable at presentation; of these, seven had more than two clonal rearrangements; this latter group showed a similar disease-free survival (DFS) to the group as a whole. Thirty of 35 patients were analyzed before their second course of intensification therapy at week 20. At this point, nine of 30 had a detectable clonal rearrangement, eight (89%) of whom have since relapsed with a median DFS of 27.5 months. Of the rest of the group (n=21), in whom no clonal rearrangement was detectable, only six (21%) have relapsed. CONCLUSION: Fluorescent IgH PCR at week 20 provides a sensitive and specific means to predict ultimate relapse (57% and 89%, respectively) and is a simple yet promising technique for the identification of patients at risk of poor outcome.     

Allogenic transplantation of hematopoietic stem cells in the treatment of children with high-risk acute leukemia

BACKGROUND: Most children with acute lymphoblastic leukemia (ALL) and increasing number of children with acute myelogenous leukemia (AML) are currently cured with conventional chemotherapy. Despite of this success there is a subset of patients with high-risk features at diagnosis who are predisposed to a very high risk of relapse. Relapse of AML and early bone marrow relapse of ALL can not be cured by conventional chemotherapy. Allogeneic hematopoietic stem cell transplantation (HSCT) is therapeutic option in these children with very high-risk acute leukemia. METHODS AND RESULTS: Between XI/1989-XII/1996 33 children with acute leukemia (ALL: 22, AML: 11) underwent an allogeneic HSCT from HLA identical related donors (HLA-identical sibling: 30, twin: 1, other HLA-identical relative: 2) at the 2nd Dept. of Pediatrics, University Hospital Motol. Median age of our group was 9 years (1.5-19 y.), boys (n = 23) clearly dominated over the girls (n = 10). The resource of stem cells was bone marrow in 31 children, bone marrow and peripheral blood progenitor cells (PBPC) and PBPC in one child respectively. Myeloablative conditioning regimen varied, consisting of total body irradiation and chemotherapy in 21 children and chemotherapy in 12 children. HSCT was performed in first complete remission of acute leukemia in 9 children (AML: 7, ALL: 2), in second remission in 14 children (AML: 2, ALL: 12), in third remission in 4 children (ALL: 4). Six children underwent HSCT in first partial remission (n = 1) and in second (n = 4) or third (n = 1) chemoresistant relapse. Seven (21%) children died due to post-transplant complications. Nine (28%) children suffered from clinically significant acute graft-versus-host reaction (GVH) and 15% (4/27) children who survived 100 days post-transplant suffered from chronic GVH disease. Relapse of leukemia was diagnosed in 39% (12/31) children. Fourteen (42%) children are alive and well in continuous remission with median follow-up 42 months. CONCLUSIONS: Allogeneic HSCT can cure children with very high-risk acute leukemia in the situations where conventional chemotherapy fails. Relapse of leukemia and GVH reaction are most important causes of post-transplant morbidity and mortality.     

伴NPM1基因突变的成年人急性髓系白血病临床研究

目的 探讨我国成年伴NPM1基因突变的急性髓系白血病患者(NPMc+AML)的临床特点,初步探讨定期定性检测该突变在早期判断AML复发中的意义.方法 采用聚合酶链反应(PCR)-毛细管电泳法对95例成年初治AML患者检测NPM1突变情况,并选取其中5例完全缓解患者定期检测该突变.结果 95例成年AML患者NPM1突变发生率为29.5%(28/95);≥40岁患者突变发生率[40.0%(22/55)]明显高于＜40岁患者[15.0%(6/40)](λ 2=6.963,P=0.012);正常核型AML患者突变发生率[51.1%(24/47)]明显高于异常核型患者[8.3%(4/48)](λ2=20.860,P=0.000).AML患者发生NPM1突变以M5[72.7%(16/22)]、M2[36.3%(8/22)]常见,在具有重现性染色体异常的AML中,未发现该突变.NPMc+AML患者白细胞、血小板计数及乳酸脱氢酶水平均明显高于NPMc-AML组(t值分别为4.132、4.603、4.069,均P＜0.05).NPMc+AML患者完全缓解率、无复发生存率及总生存率均明显高于NPMc-AML患者(λ2值分别为10.448、4.146、4.384,均P＜0.05).定期检测的患者血液学复发前1.5～2.0个月草新出现NPM1基因突变.结论 NPM1基因突变在成年AML患者中,尤其是正常核型AML患者中有较高的发生率,临床表现为患者年龄偏大,白细胞计数、血小板计数、乳酸脱氢酶均较高,NPM1基因突变是成年AML患者预后良好的指标.定期定性监测该突变可早期判断AML复发.     

Tumor suppressor gene alteration in adult acute lymphoblastic leukemia (ALL). Analysis of retinoblastoma (Rb) and p53 gene expression in lymphoblasts of patients with de novo, relapsed, or refractory ALL treated in Southwest Oncology Group studies

To examine the impact of inactivation of tumor suppressor genes on outcome in adult ALL, we compared two groups of patients registered to SWOG treatment protocols for loss of the Rb gene product and p53 overexpression: (1) 89 patients with de novo ALL, and (2) 26 patients with relapsed/refractory ALL. The groups were comparable with respect to age, sex, and race. Cell lysates (> or = 80% blasts) were analyzed by immunoblotting which enabled detection of Rb or p53 proteins in as little as 1 microg of lysate. Loss of Rb expression (pRbneg) was found in 54/85 (64%) de novo and 11/19 (58%) relapsed patients (P = 0.79). Overexpression of p53 (p53abn), indicative of p53 point mutations, was found in 16/75 (21%) de novo and 8/19 (42%) relapsed patients (P = 0.08). Using a nonisotopic RNase cleavage assay, p53 point mutations in exons 5-9 were confirmed in 14/23 (61%) p53abn specimens. For the de novo ALL group, patients with normal Rb protein had higher WBC and higher peripheral blast and lymphocyte counts. Otherwise neither abnormal Rb or p53 expression correlated with any of a large panel of clinical and laboratory variables including FAB class, blast lineage, expression of myeloid antigens or CD34, and presence of the Ph1 chromosome or BCR-ABL. Analyses of treatment outcomes demonstrated no significant impact of Rb or p53 status alone on CR rates, relapse-free or overall survival. An identical percentage (11%) of both de novo and relapsed/refractory patients had concurrent abnormalities of both Rb and p53 expression (pRbneg/p53abn). The survival curve of these patients suggests an increased rate of early death, but the number of patients in this group was small. Summarizing, (1) loss of Rb expression is common in adult ALL; (2) overexpression of p53 may be more frequent in relapsed/refractory than de novo adult ALL; and (3) although Rb or p53 alterations alone are not strong independent predictors of outcome, their concurrent expression may predict a poor response to therapy.     

A phase II study with high-dose cytarabine (NS-075) in adult patients with relapsed and refractory acute leukemia

A multi-center phase II clinical study with high dose cytarabine (NS-075) was conducted in adult patients with relapsed and/or refractory acute leukemia. 2 g/m2 cytarabine was given 12 times by 3-hour intravenous infusion every 12 hrs. 46 patients were registered, and 44 were evaluable: 35 with acute myeloid leukemia (AML) and 9 with acute lymphoblastic leukemia (ALL). There were 28 males and 16 females, with a median age of 37.5 years (range 15-68), including 6 of more than 60 years. Among 35 patients with AML, there were 16 (45.7%) complete and 2 (5.7%) partial remissions. Among 9 patients with ALL, there were 2 (22.2%) complete and 1 (11.1%) partial remissions. The major non-hematologic toxicities were gastrointestinal symptoms such as nausea/vomiting, anorexia and diarrhea, as well as fever, infection, conjunctivitis, alopecia, hepatic and renal dysfunctions. Central nervous system (CNS) toxicity was mild and reversible. Therapy-related death occurred in 5 patients resulting from prolonged pancytopenia, which suggests the necessity of strict countermeasures for infections as well as good patient care. These results indicate that high-dose cytarabine is a promising therapy for treatment of relapsed and/or refractory acute leukemia.