An international study of intrachromosomal amplification of chromosome 21 (iAMP21): cytogenetic characterization and outcome.

Intrachromosomal amplification of chromosome 21 (iAMP21) defines a distinct cytogenetic subgroup of childhood B-cell precursor acute lymphoblastic leukaemia (BCP-ALL). To date, fluorescence in situ hybridisation (FISH), with probes specific for the RUNX1 gene, provides the only reliable detection method (five or more RUNX1 signals per cell). Patients with iAMP21 are older (median age 9 years) with a low white cell count. Previously, we demonstrated a high relapse risk when these patients were treated as standard risk. Recent studies have shown improved outcome on intensive therapy. In view of these treatment implications, accurate identification is essential. Here we have studied the cytogenetics and outcome of 530 iAMP21 patients that highlighted the association of specific secondary chromosomal and genetic changes with iAMP21 to assist in diagnosis, including the gain of chromosome X, loss or deletion of chromosome 7, ETV6 and RB1 deletions. These iAMP21 patients when treated as high risk showed the same improved outcome as those in trial-based studies regardless of the backbone chemotherapy regimen given. This study reinforces the importance of intensified treatment to reduce the risk of relapse in iAMP21 patients. This now well-defined patient subgroup should be recognised by World Health Organisation (WHO) as a distinct entity of BCP-ALL.

An intragenic ERG deletion is a marker of an oncogenic subtype of B-cell precursor acute lymphoblastic leukemia with a favorable outcome despite frequent IKZF1 deletions.

Oncogenic subtypes in childhood B-cell precursor acute lymphoblastic leukemia (BCP-ALL) are used for risk stratification. However, a significant number of BCP-ALL patients are still genetically unassigned. Using array-comparative genomic hybridization in a selected BCP-ALL cohort, we characterized a recurrent V(D)J-mediated intragenic deletion of the ERG gene (ERG(del)). A breakpoint-specific PCR assay was designed and used to screen an independent non-selected cohort of 897 children aged 1-17 years treated for BCP-ALL in the EORTC-CLG 58951 trial. ERG(del) was found in 29/897 patients (3.2%) and was mutually exclusive of known classifying genetic lesions, suggesting that it characterized a distinct leukemia entity. ERG(del) was associated with higher age (median 7.0 vs. 4.0 years, P=0.004), aberrant CD2 expression (43.5% vs. 3.7%, P<0.001) and frequent IKZF1 Δ4-7 deletions (37.9% vs. 5.3%, P<0.001). However, ERG(del) patients had a very good outcome, with an 8-year event-free survival (8-y EFS) and an 8-year overall survival of 86.4% and 95.6%, respectively, suggesting that the IKZF1 deletion had no impact on prognosis in this genetic subtype. Accordingly, within patients with an IKZF1 Δ4-7 deletion, those with ERG(del) had a better outcome (8-y EFS: 85.7% vs. 51.3%; hazard ratio: 0.16; 95% confidence interval: 0.02-1.20; P=0.04). These findings have implications for further stratification including IKZF1 status.

Age and high-dose methotrexate are associated to clinical acute encephalopathy in FRALLE 93 trial for acute lymphoblastic leukemia in children.

The objective of the study was to assess acute neurotoxicity associated with triple intrathecal therapy (TIT)+/-high-dose methotrexate (HD MTX) in children with acute lymphoblastic leukemia (ALL). 1395 children were enrolled on FRALLE 93 protocol from 1993 to 1999. Lower-risk group (LR, n=182) were randomized to weekly low-dose MTX at 25 mg/m(2)/week (LD MTX, n=81) or HD MTX at 1.5 g/m(2)/2 weeks x 6 (n=77). Intermediate-risk group (IR, n=672) were randomized to LD MTX (n=290) or HD MTX at 8 g/m(2)/2 weeks x 4 (n=316). Higher-risk group (HR, n=541) prednisone-responder patients received LD MTX and cranial radiotherapy. HR group steroid resistant cases were grafted (autologous or allogenic). TIT (MTX, cytarabine and methylprednisolone) was given every 2 weeks during 16-18 weeks and every 3 months during maintenance therapy in LR and IR patients. 52 patients (3.7%) developed neurotoxicity. Isolated seizures: n=15 (1.1%), peripheral and spinal neuropathy: n=17 (1.2%) and encephalopathy: n=20 (1.4%). Age >10 years was significantly associated with neurotoxicity (P=0.01) and use of HD MTX is associated with encephalopathy (P=0.03). Sequels are reported respectively in 60 and 33% of spinal neuropathy and encephalopathy cases. Current strategies tailoring risk of neurological sequels has to be defined.

Survival in France after childhood acute leukaemia and non-Hodgkin's lymphoma (1990-2000).

This article describes the survival after childhood acute leukaemia (AL) and non-Hodgkin's lymphoma (NHL) of French population aged less than 15 years. The French National Registry of Childhood Leukaemia and Lymphoma recorded 3995 cases of acute lymphoblastic leukaemia (ALL), 812 of acute myeloid leukaemia (AML) and 1137 of NHL over the period from 1990 to 2000. Overall survival rates at 5 years were 82% (95% CI 80-83), 58% (95% CI 54-61) and 87% (95% CI 85-89) for ALL, AML and NHL, respectively. Survival after AL increased from 77% (95% CI 75-80) in 1990-1992 to 85% (95% CI 83-87) in 1997-2000 for ALL and from 47% (95% CI 41-54) to 61% (95% CI 55-67) for AML. Among AL cases, children aged 1-4 years had the most favourable prognosis. Down's syndrome was associated with poor survival after ALL. No gender-related variations in survival were in evidence. The results reported herein are similar to those reported by other European registries and clinical trials.

Acute childhood leukaemia and environmental exposure to potential sources of benzene and other hydrocarbons; a case-control study.

AIM: To analyse the association between potential environmental exposure to hydrocarbons and the risk of acute childhood leukaemia. METHODS: A hospital based multicentre case control study, stratified on centre, age, and sex, with 280 leukaemia cases and 285 controls was carried out. Data were collected by a standardised interview of the mothers. RESULTS: No clear association was seen between maternal occupational exposure to hydrocarbons during pregnancy and leukaemia, or between residential traffic density and leukaemia. There was an association between dwellings neighbouring a petrol station or a repair garage during childhood and the risk of childhood leukaemia (OR 4.0, 95% CI 1.5 to 10.3), with a duration trend. The association, which appeared particularly strong for acute non-lymphocytic leukaemia (OR 7.7, 95% CI 1.7 to 34.3), was not altered by adjustment for potential confounding factors. CONCLUSIONS: Results showed an association between acute childhood leukaemia and dwellings neighbouring auto repair garages and petrol stations, which are benzene emitting sources. These findings could be due to chance, although the strength of the association and the duration trend are arguments for a causal association.

Incidence of childhood leukaemia and non-Hodgkin's lymphoma in France: National Registry of Childhood Leukaemia and Lymphoma, 1990-1999.

The French National Registry of Childhood Leukaemia and Lymphoma (NRCL) covers the whole French mainland population aged less than 15 years (approximately 11 million children) for all childhood haematopoietic tumours since 1 January 1990, except Hodgkin's disease, which has been registered since 1 January 1999. During the period from 1990 to 1999, 5757 cases of leukaemia, lymphoma and myelodysplastic syndrome were registered in the NRCL, with an average of 2.5 sources per case. The age-standardized incidence rates per million per year were 43.1 for leukaemia (34.3 for acute lymphoblastic leukaemia, 7.1 for acute myeloblastic leukaemia, 0.6 for chronic myeloid leukaemia and 0.5 for chronic myelomonocytic leukaemia), 8.9 for non-Hodgkin's lymphomas and 6.7 for Hodgkin's disease. Down's syndrome was present in 110 cases of acute leukaemia (2.5%) and three cases of non-Hodgkin's lymphoma (0.3%). The incidence of acute lymphoblastic leukaemia showed a typical peak at age 2 years for girls and 3 years for boys. The incidence rates of leukaemia and non-Hodgkin's lymphoma did not show any temporal trends over the 10 year period.

Secondary cytogenetic aberrations in childhood Philadelphia chromosome positive acute lymphoblastic leukemia are nonrandom and may be associated with outcome.

Additional chromosomal aberrations occur frequently in Philadelphia chromosome positive (Ph+) acute lymphoblastic leukemia (ALL) of childhood. The treatment outcome of these patients is heterogeneous. This study assessed whether such clinical heterogeneity could be partially explained by the presence and characteristics of additional chromosomal abnormalities. Cytogenetic descriptions were available for 249 of 326 children with Ph+ ALL, diagnosed and treated by 10 different study groups/large single institutions from 1986 to 1996. Secondary aberrations were present in 61% of the cases. Chromosomes 9, 22, 7, 14, and 8 were most frequently abnormal. Most (93%) karyotypes were unbalanced. Three main cytogenetic subgroups were identified: no secondary aberrations, gain of a second Ph and/or >50 chromosomes, or loss of chromosome 7, 7p, and/or 9p, while other secondary aberrations were grouped as combinations of gain and loss or others. Of the three main cytogenetic subgroups, the loss group had the worst event-free survival (P=0.124) and disease-free survival (P=0.013). However, statistical significance was not maintained when adjusted for other prognostic factors and treatment. Karyotypic analysis is valuable in subsets of patients identified by molecular screening, to assess the role of additional chromosomal abnormalities and their correlation with clinical heterogeneity, with possible therapeutic implications.

Day-care, early common infections and childhood acute leukaemia: a multicentre French case-control study.

We conducted a case-control study to investigate the role of early infections in the aetiology of childhood acute leukaemias. The study included 280 incident cases (240 acute lymphoblastic leukaemia and 40 acute non-lymphoblastic leukaemia) and 288 hospital controls, frequency matched by age, gender, hospital, catchment area of the hospital and ethnic origin. Data were obtained from standardised face-to-face interviews of the mothers. The interviews included questions on early common infections, day-care attendance, breast-feeding, birth order and infantile diseases. Odds ratios were estimated using an unconditional regression model including the stratification variables, parental socio-economic status and perinatal characteristics. Birth order was not associated with childhood leukaemia (acute lymphoblastic or acute non-lymphoblastic). A statistically-significant inverse association was observed between childhood leukaemia and day-care attendance (odds ratio=0.6, 95% Confidence Interval=(0.4-1.0)), repeated early common infections (> or = 4 per year before age two, odds ratio=0.6 (0.4-1.0)), surgical procedures for ear-nose-throat infections before age two (odds ratio=0.5 (0.2-1.0)) and prolonged breast-feeding (> or = 6 months, odds ratio=0.5 (0.2-1.0)). In the multivariate model including day-care attendance, early common infections and breast-feeding, results concerning breast-feeding remained unchanged. A statistically significant interaction between day-care attendance and repeated early common infections was observed. When the interaction was taken into account, the simple effects of day-care and early common infections disappeared (odds ratio=1.1 (0.5-2.3) and odds ratio=0.8 (0.5-1.3), respectively) while the joint effect of day-care attendance and early common infections was negatively associated with childhood leukaemia (odds ratio=0.3 (0.1-0.8)). All the above associations were observed both for acute lymphoblastic leukaemia and acute non-lymphoblastic leukaemia. Our results support Greaves' hypothesis, even though they are not specific of common leukaemia.

[Prognosis of acute lymphoblastic leukemia in children. Results of the French protocol FRALLE 93]. / Le pronostic des leucémies aiguës lymphoblastiques (LAL) de l'enfant. Résultats du protocole français FRALLE 93.

1,120 children were included in protocol FRALLE 93 from june 1993 to september 1998. Disease Free Survival for the all protocol is 78% +/- 3 and overall survival 83% +/- 3. Various clinical and laboratory features at the time of diagnosis have been correlated with prognosis. They provide a potential mean to stratify patients into treatment subgroups according their relative risk of treatment failure. The identification of these prognostic factors has been an essential element in the design of current therapeutic trials. Prognostic characteristics of childhood ALL include: age, white blood cell count, tumor burden, cytogénétics (chromosome count and chromosomal translocation), immunophenotype and early response to treatment. Molecular biology has been the revolution of the last two decades permitting the cloning of the genes involved in the leukemic process. Finally the new molecular techniques allow a sensitive diagnostic approach to minimal residual disease (MRD). The better detection of MRD must allow a more rational basis for therapeutic intensification for a subset of poor responder patients. A decrease in therapy of very good responders can also be envisaged.

Prognostic study of continuous variables (white blood cell count, peripheral blast cell count, haemoglobin level, platelet count and age) in childhood acute lymphoblastic leukaemia. Analysis Of a population of 1545 children treated by the French Acute Lymphoblastic Leukaemia Group (FRALLE).

Many cutpoints have been proposed to categorize continuous variables in childhood acute lymphoblastic leukaemia (white blood cell count, peripheral blast cell count, haemoglobin level, platelet count and age), and have been used to define therapeutic subgroups. This variation in the choice of cutpoints leads to a bias called the 'Will Rogers phenomenon'. The aim of this study was to analyse variations in the relative risk of relapse or death as a function of continuous prognostic variables in childhood ALL and to discuss the choice of cutpoints. We studied a population of 1545 children with ALL enrolled in three consecutive protocols named FRALLE 83, FRALLE 87 and FRALLE 89. We estimated the risk of relapse or death associated with different values of each continuous prognostic variable by dividing the sample into quintiles of the distribution of the variables. As regards age, a category of children under 1 year of age was distinguished and the rest of the population was divided into quintiles. The floated variance method was used to calculate the confidence interval of each relative risk, including the reference category. The relation between the quantitative prognostic factors and the risk was monotonic for each variable, except for age. For the white blood cell count (WBC), the relation is log linear. The risk associated with WBC values in the upper quintile was 1.9 times higher than that in the lower quintile. The peripheral blast cell count correlated strongly with WBC (correlation coefficient: 0.99). The risk increased with the haemoglobin level, and the risk in the upper quintile was 1.3 times higher than that in the lower quintile. The risk decreased as the platelet count increased: the risk in the lower quintile was 1.2 times higher than that in the upper quintile. The risk increased gradually with increasing age above one year. The small subgroup of patients (2.5% of the population) under 1 year of age at diagnosis had a risk 2.6 times higher than the reference category of patients between 3 and 4.3 years of age. When the risk associated with a quantitative prognostic factor varies monotonously, the selection of a cutpoint is arbitrary and represents a loss of information. Despite this loss of information, such arbitrary categorization may be necessary to define therapeutic stratification. In that case, consensus cutpoints must be defined if one wants to avoid the Will Rogers phenomenon. The cutpoints proposed by the Rome workshop and the NCI are arbitrary, but may represent an acceptable convention.

Use of recombinant human granulocyte colony-stimulating factor to increase chemotherapy dose-intensity: a randomized trial in very high-risk childhood acute lymphoblastic leukemia.

PURPOSE: To determine whether the use of a recombinant human granulocyte colony-stimulating factor ([G-CSF] lenogastrim) can increase the chemotherapy dose-intensity (CDI) delivered during consolidation chemotherapy of childhood acute lymphoblastic leukemia (ALL). PATIENTS AND METHODS: Sixty-seven children with very high-risk ALL were randomized (slow early response to therapy, 55 patients; translocation t(9;22) or t(4;11), 12 patients). Consolidation consisted of six courses of chemotherapy; the first, third, and fifth courses were a combination of high-dose cytarabine, etoposide, and dexamethasone (R3), whereas the second, fourth, and sixth courses included vincristine, prednisone, cyclophosphamide, doxorubicin, and methotrexate (COPADM). G-CSF was given after each course, and the next scheduled course was started as soon as neutrophil count was > 1 x 10(9)/L and platelet count was > 100 x 10(9)/L. CDI was calculated using the interval from day 1 of the first course to hematologic recovery after the fifth course (100% CDI = 105-day interval). RESULTS: CDI was significantly increased in the G-CSF group compared with the non-G-CSF group (mean +/- 95% confidence interval, 105 +/- 5% v 91 +/- 4%; P <.001). This higher intensity was a result of shorter post-R3 intervals in the G-CSF group, whereas the post-COPADM intervals were not statistically reduced. After the R3 courses, the number of days with fever and intravenous antibiotics and duration of hospitalization were significantly decreased by G-CSF, whereas reductions observed after COPADM were not statistically significant. Duration of granulocytopenia was reduced in the G-CSF group, but thrombocytopenia was prolonged, and the number of platelet transfusions was increased. Finally, the 3-year probability of event-free survival was not different between the two groups. CONCLUSION: G-CSF can increase CDI in high-risk childhood ALL. Its effects depend on the chemotherapy regimen given before G-CSF administration. In our study, a higher CDI did not improve disease control.

Critical study of prognostic factors in childhood acute lymphoblastic leukaemia: differences in outcome are poorly explained by the most significant prognostic variables. Fralle group. French Acute Lymphoblastic Leukaemia study group.

We determined the proportion of survival variability explained by the usual prognostic factors in childhood acute lymphoblastic leukaemia (ALL) during a prognostic study of 1552 patients enrolled in three consecutive Fralle group protocols (Fralle 83, Fralle 87 and Fralle 89). The event-free survival rates at 5 years were 54.8% (SD 1.9), 43.1%) (SD 2.7) and 55.6% (SD 2.2), respectively. In the univariate analysis the following variables were predictive of poor outcome: male gender, elevated leucocytosis (> 50 x 10(9)/l), circulating blastosis. haemoglobin >12 g/dl, platelet count <100 x 10(9)/l, age under 1 year or over 9 years, enlarged mediastinum, nodes, spleen and liver, T phenotype, absence of CD10+ cells; testicular and meningeal involvement, poor response to induction therapy (CCSG M3), and LDH >400 U/l. Among the cytogenetic features, hyperdiploidy had a protective effect, whereas hypodiploidy, translocation and other structural abnormalities had a negative influence, particularly in cases of t(9;22) or t(4;11). Multivariate analysis summarized the prognostic information in terms of four variables: age, gender, leucocytosis and cytogenetic features. Missing data had little influence on the results. However, despite their significance in the multivariate analysis, these four variables each had very low predictive power (1.1% for gender, 2.0% for age, 3.5% for leucocytosis, and 1.6% for cytogenetic features). Thus, the most significant prognostic factors in childhood ALL each explain no more than 4% of the variability in prognosis. This may explain the disappointing practical value of these factors and underlines the need for prognostic tools in childhood ALL.

The majority of myeloid-antigen-positive (My+) childhood B-cell precursor acute lymphoblastic leukaemias express TEL-AML1 fusion transcripts.

The t(12:21) translocation fuses the TEL and AML1 genes and has been found in up to 28% of paediatric B-cell precursor acute lymphoblastic leukaemias (BCP-ALL). The AML1 gene is a transcription factor which regulates expression of several myeloid differentiation associated genes. A molecular analysis of TEL-AML1, E2A-PBX1, MLL-AF4, BCR-ABL expression and an immunophenotypic study of CD13/CD33 myeloid antigen expression have been performed prospectively on tumour cells from 96 paediatric BCP-ALL patients. Percentages of CD13 or CD33 expressing leukaemic cells were found to be higher in TEL-AML1 positive cases (n = 22) than in TEL-AML1 negative (n = 74) cases (P<0.001). In 22/96 cases (23%) >10% of neoplastic cells were found to express at least one of the two markers. In 14 of these cases (63%), TEL-AML1 expression was detected, whereas t(4;11), t(11;19) and t(9;22) translocations were found by molecular methods in only three cases (14%). In four cases (18%) no molecular marker was found. These data show that TEL-AML1 expression is significantly associated with myeloid antigen expression by leukaemic cells and suggests that the prognostic significance of myeloid antigen expression in paediatric ALLs should be re-evaluated in the light of molecular cytogenetic markers.

TEL-AML1 fusion RNA as a new target to detect minimal residual disease in pediatric B-cell precursor acute lymphoblastic leukemia.

It has recently been shown that the t(12;21)(p13;q22) translocation fuses two genes, TEL on chromosome 12 and AML1 on chromosome 21. We have evaluated the frequency of this newly described translocation in acute lymphoblastic leukemia (ALL), and the feasibility of minimal residual disease (MRD) monitoring by polymerase chain reaction (PCR) amplification of TEL-AML1 transcripts. Thirty-nine adult- and 45 childhood-ALLs consecutively diagnosed in a single center were included in this study. TEL-AML1 fusion transcripts were searched for in the 39 adult- and 45 childhood-ALLs for which material was available. BCR-ABL, E2A-PBX1, and MLL-AF4 transcripts were also studied by PCR in these cases. TEL-AML1 transcripts were found in 8 out of 35 (23%) childhood B-cell precursor ALLs (BCP-ALLs). TEL-AML1 transcripts were detected in only 1 of 31 adult BCP-ALLs (P = .04, Fisher's exact test). Nevertheless, in this adult case, TEL-AML1 transcripts were found at a low level in 2 of 3 different samples. BCR-ABL, E2A-PBX1, and MLL-AF4 transcripts were found in 12, 3, and 1 cases of 31 adult BCP-ALLs, and in 1, 2, and 1 cases of 35 childhood BCP-ALLs, respectively. TEL-AML1 transcripts were never found associated with any other fusion transcripts. Taken together, the four types of chimeric transcripts were detected in 12 of 35 (34%) childhood BCP-ALL cases. No TEL-AML1 transcripts were detected in 11 T-cell ALLs (4 adults and 5 children), nor in 2 B-cell (slg+) ALLs. MRD was evaluated in 21 samples collected in 9 TEL-AML1+ childhood BCP-ALL cases during therapy (median follow-up = 200 days). Of 8 patients evaluated after induction therapy, 4 showed detectable but low levels of MRD. Of 7 patients serially evaluated, only one showed persistence of detectable MRD. This study shows that TEL-AML1 transcripts are frequently detected in pediatric BCP-ALLs and that these transcripts are molecular targets that will simplify the strategy of MRD monitoring in childhood BCP-ALL.

Neoadjuvant chemotherapy of breast cancer.

About 80% of patients with breast cancer ultimately die of metastatic disease at 20 years. Distant metastases are more important as a cause of death than local or regional relapses. It is for this reason that adjuvant chemotherapy is necessary, especially in young patients and those with extensive disease. Initial chemotherapy preceding any local or regional treatment is justified on the grounds that both surgery and anaesthesia lead to immunodepression. Further, the value of initial chemotherapy has been demonstrated in many experimental and clinical trials by Nissen-Meyer, Bonadonna and Cooper (1-3). In the present study 145 patients, including 67 with inflammatory breast cancer (IBC), were treated with 4-6 weeks of Velbe, thiotepa, methotrexate, fluorouracil and prednisone, with Adriblastin added for patients with IBC, T greater than 7 cm, or N2, N3. Because of tumour regression of greater than 50% observed in 80% of the patients, the majority (123 patients) then received radiotherapy alone (cobalt + iridium), resulting in complete remission in all these cases. Maintenance treatment with the same drugs was prescribed for 6-18 months depending on the initial stage. Tumour regression appears to be an important prognostic factor. Median follow-up is only 17 months, the longest being 42 months. Overall survival at 2 years for IBC is 90%, with a disease-free survival of 80%. Cosmetic results are excellent. While these results are encouraging, longer follow-up is needed to confirm this improvement.