Philadelphia chromosome-positive acute lymphoblastic leukemia in children: durable responses to chemotherapy associated with low initial white blood cell counts

Hematopoietic stem cell transplantation from HLA-matched sibling donors in children with acute lymphoblastic leukemia: A report from the Children’s Cancer Hospital Egypt

Introduction

Allogeneic hematopoietic stem cell transplantation (HSCT) is widely used for high-risk acute lymphoblastic leukemia (ALL) patients in their first complete remission (CR1), and for relapsed patients in second complete remission (CR2).

Patients and methods

We retrospectively analyzed data for 67 children with ALL, from a cancer center in a low/middle income country, who had undergone HSCT from human leukocyte antigen (HLA)-matched sibling donors (MSDs) using myeloablative conditioning (MAC) regimens, between 2007 and 2020, describing the survival outcome and relapse probability after achieving CR1 and CR2 and determining outcome differences in relation to indications for HSCT in patients transplanted in CR1. All patients had achieved a negative minimal residual disease prior to transplant (<0.01%).

Results

Forty-six patients (68.7%) were in CR1; 25 had adverse cytogenetics, including 18 patients with Philadelphia chromosome-positive ALL (Ph-positive ALL), and 21 had poor induction response. The 5-year overall survival (OS), event-free survival (EFS) and cumulative incidence of relapse (CIR) for the whole cohort were 56.1% (95% CI, 42.8%-69.4%), 49% (95% CI, 35.7%-62.3%) and 33.5% (95% CI, 21.7%-45.8%), respectively with better EFS and CIR for CR1 transplants compared to CR2 transplants (P=0.02 and P=0.03, respectively). Patients with Ph-positive ALL had better 5-year OS, EFS and non-relapse mortality (NRM) compared with other CR1 transplants (P=0.015, P=0.009 and P=0.028, respectively).

Conclusion

Hematopoietic stem cell transplantation from MSD for ALL in CR1 group had superior outcomes compared to CR2 group and was apparently a curable option for Ph-positive ALL without an increased risk of non-relapse mortality. Poorer survival rates and higher relapse probabilities were associated with HSCT conducted to patients who had a poor response to induction therapy or suffered a relapse.

St. Jude Total Therapy studies from I to XVII for childhood acute lymphoblastic leukemia: a brief review

The therapy design of childhood acute lymphoblastic leukemia (ALL) has evolved over the past 60 years. The St. Jude Children's Research Hospital has developed 17 treatment protocols from 1962 to 2017, aiming to have the most effective and least toxic treatment form. This review summarizes each protocol's objectives, inclusion criteria, treatment phases, pharmacological agents, irradiation therapy, response criteria, risk stratification, type of relapse, and overall survival. The enhancement and successful application of preventive therapy for ALL and following a risk-stratified approach have progressively improved the cure rate of childhood ALL, with relatively few adverse sequelae. Moreover, St. Jude's scientific theme serves as a reminder of the principal factor of research directed to a catastrophic disease such as ALL.

Use of tyrosine kinase inhibitors for paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia: a systematic review and meta-analysis

OBJECTIVES

To investigate the effectiveness and safety of tyrosine kinase inhibitors (TKIs) in the management of paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (Ph+ALL).

DESIGN

A systematic review and meta-analysis.

DATA SOURCES

Electronic searches were conducted on CENTRAL, MEDLINE, EMBASE, SIOP, ASPHO, ASCO, ASH and four Chinese databases from inception to 8 March 2020. Language of publications was restricted in English and Chinese.

ELIGIBILITY CRITERIA

Prospective and retrospective comparative studies were included.

DATA EXTRACTION AND SYNTHESIS

Two authors independently assessed and extracted data. Quality of studies was assessed by the Cochrane Collaboration's tool and Newcastle-Ottawa Scale. Subgroup analysis was performed by comparing different types of TKIs. Quality of evidence was assessed using the Grading of Recommendations Assessment, Development and Evaluation approach.

RESULTS

Two randomised controlled trials (RCTs) and four cohort studies enrolling 536 patients were included. For RCTs, the pooled HR was 0.68 (95% CI 0.26 to 1.78) in overall survival (OS), 0.63 (95% CI 0.28 to 1.42) in event-free survival (EFS), respectively, comparing TKI arm with non-TKI arm for treatment of paediatric Ph+ALL. There was significant difference in OS and EFS between imatinib arm and dasatinib arm (HR 2.26, 95% CI 1.02 to 5.01; HR 2.36; 95% CI 1.27 to 4.39, respectively). For cohort studies, the pooled HR was 0.25 (95% CI 0.14 to 0.47) in OS, 0.25 (95% CI 0.12 to 0.56) in EFS, respectively, comparing TKI arm with non-TKI arm. There was no significance difference in adverse drug reaction between TKI group and without TKI group (risk ratio (RR) 0.82, 95% CI 0.63 to 1.08 in RCT; RR 1.01, 95% CI 0.64 to 1.59 in cohort studies; respectively), and imatinib versus dasatinib (RR 0.97, 95% CI 0.77 to 1.23). The quality of evidence was rated as low for OS, EFS and adverse drug reaction (ADR).

CONCLUSIONS

The combination of TKIs with chemotherapy is likely to improve the OS and EFS rates in paediatric Ph+ALL, and dasatinib is superior than imatinib. Large sample size and prospective controlled studies are warranted.

PROSPERO REGISTRATION NUMBER

CRD42018104107.

[Prognostic factors of pediatric patients with Ph-positive acute lymphoblastic leukemia]

Objective: To explore the clinical features and prognostic factors of Ph-positive and/or BCR-ABL positive acute lymphoblastic leukemia (Ph⁺ ALL) in children. Methods: The clinical data of 68 Ph⁺ ALL children who were treated at Peking University People's Hospital from December 2006 to December 2016 was retrospectively reviewed. Survival analysis were estimated by Kaplan-Meier method. Univariate analysis was estimated by Log-rank test and Chi-square, and multivariate analysis was estimated by Cox proportional hazards regression model. Results: In the 68 cases, the proportion of male to female was 2.1∶1, with a median age of 8 (1-16) years, and the median overall survival (OS) and disease free survival (DFS) were 16.8 months and 13.5 months, respectively. The early response rate to treatment was 43.9%, with myeloid-antigens-expression group lower than the non-expression group (29.6% vs 61.3%, χ²=5.814, P=0.020); The complete remission (CR) rate after one-course induction therapy was 86.2% (56/65), with good-response group higher than the poor-response group (100.0% vs 74.2%, χ²=6.680, P=0.003);The CR rate after induction in patients receiving imatinib plus chemotherapy was higher than the patients receiving chemotherapy only (94.9% vs 73.1%, χ²=5.185, P=0.024). The 2-and 5-year OS were (61.4±7.0)% and (50.8±8.1)%, respectively. The 2-and 5-year DFS were (54.6±6.8)% and (48.6±7.3)%, respectively. Univariate analysis showed that the initial WBC, LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year OS rate (all P<0.05). LDH, spleen size, liver size, with-myeloid-antigens-expression, early response to treatment, MRD (BCR-ABL) after one-course induction, application of imatinib and different treatment options affected 2-year DFS rate (all P<0.05). Multivariate prognostic analysis for OS (RR=45.7, 95% CI 1.4-1 528.2, P=0.033) and DFS (RR=52.3, 95% CI 1.6-1 725.9, P=0.026) showed that the spleen ≥ 3 cm was the independent risk factor. Conclusions: Pediatric Ph⁺ ALL is a special condition with unique clinical and biological features. The early response to treatment was poor in patients with myeloid-antigens-expression, which resulted in a low CR rate after one-course induction and the administration of imatinib can remarkably improve the CR rate. Initial spleen ≥ 3 cm is an independent prognostic factor. The efficacy of chemotherapy alone is poor, and imatinib combined with chemotherapy is applauded in the aim of improving outcomes.

Childhood pre-B cell acute lymphoblastic leukemia with translocation t(1;19)(q21.1;p13.3) and two additional chromosomal aberrations involving chromosomes 1, 6, and 13: a case report

Background

The translocation t(1;19)(q23;p13), which results in the TCF3-PBX1 chimeric gene, is one of the most frequent rearrangements observed in B cell acute lymphoblastic leukemia. It appears in both adult and pediatric patients with B cell acute lymphoblastic leukemia at an overall frequency of 3 to 5%. Most cases of pre-B cell acute lymphoblastic leukemia carrying the translocation t(1;19) have a typical immunophenotype with homogeneous expression of CD19, CD10, CD9, complete absence of CD34, and at least diminished CD20. Moreover, the translocation t(1;19) correlates with known clinical high risk factors, such as elevated white blood cell count, high serum lactate dehydrogenase levels, and central nervous system involvement; early reports indicated that patients with translocation t(1;19) had a poor outcome under standard treatment.

Case presentation

We report the case of a 15-year-old Syrian boy with pre-B cell acute lymphoblastic leukemia with abnormal karyotype with a der(19)t(1;19)(q21.1;p13.3) and two yet unreported chromosomal aberrations: an interstitial deletion 6q12 to 6q26 and a der(13)t(1;13)(q21.1;p13). According to the literature, cases who are translocation t(1;19)-positive have a significantly higher incidence of central nervous system relapse than patients with acute lymphoblastic leukemia without the translocation. Of interest, central nervous system involvement was also seen in our patient.

Conclusions

To the best of our knowledge, this is the first case of childhood pre-B cell acute lymphoblastic leukemia with an unbalanced translocation t(1;19) with two additional chromosomal aberrations, del(6)(q12q26) and t(1;13)(q21.3;p13), which seem to be recurrent and could influence clinical outcome. Also the present case confirms the impact of the translocation t(1;19) on central nervous system relapse, which should be studied for underlying mechanisms in future.

Prognostification of ALL by Cytogenetics

Cytogenetic abnormalities in chromosomal number and structure are common in pediatric ALL and some have prognostic significance. One interesting association between cytogenetic status and treatment response involves the metabolism of methotrexate. Hyperdiploid lymphoblasts accumulate increased amounts of MTX and MTX polyglutamates, and they have higher basal apoptotic rates compared with leukemic cells with lower ploidy and normal cells. These characteristics may contribute to the better outcomes observed for patients with hyperdiploid lymphoblasts. A number of recurrent chromosomal abnormalities have been shown to have prognostic significance, especially in B-precursor ALL. Some chromosomal abnormalities are associated with more favorable outcomes, such as high hyperdiploidy (51-65 chromosomes) and the ETV6-RUNX1 fusion. Others are associated with a poorer prognosis, including the Philadelphia chromosome [t(9;22)], rearrangements of the MLL gene (chromosome 11q23), and intrachromosomal amplification of the AML1 gene (iAMP21).

Intermediate dose of imatinib in combination with chemotherapy followed by allogeneic stem cell transplantation improves early outcome in paediatric Philadelphia chromosome-positive acute lymphoblastic leukaemia (ALL): results of the Spanish Cooperative Group SHOP studies ALL-94, ALL-99 and ALL-2005

Philadelphia-chromosome acute lymphoblastic leukaemia (Ph+ ALL) is a subgroup of ALL with very high risk of treatment failure. We report here the results of the Sociedad Española de Hematología y Oncología Pediátricas (SEHOP/SHOP) in paediatric Ph+ ALL treated with intermediate-dose imatinib concurrent with intensive chemotherapy. The toxicities and outcome of these patients were compared with historical controls not receiving imatinib. Patients with Ph+ ALL aged 1-18years were enrolled in three consecutive ALL/SHOP trials (SHOP-94/SHOP-99/SHOP-2005). In the SHOP-2005 trial, imatinib (260mg/m(2) per day) was given on day-15 of induction. Allogeneic haematopoietic stem-cell transplantation (HSCT) from a matched related or unrelated donor was scheduled in first complete remission (CR1). Forty-three patients were evaluable (22 boys, median age 6·8years, range, 1·2-15). Sixteen received imatinib whereas 27 received similar chemotherapy without imatinib. Seventeen of 27 and 15 of 16 patients in the non-imatinib and imatinib cohort, respectively, underwent HSCT in CR1. With a median follow-up of 109 and 39months for the non-imatinib and imatinib cohorts, the 3-year event-free survival (EFS) was 29·6% and 78·7%, respectively (P=0·01). These results show that, compared to historical controls, intermediate dose of imatinib given concomitantly with chemotherapy and followed by allogeneic HSCT markedly improved early EFS in paediatric Ph+ ALL.

Allogeneic hematopoietic cell transplantation (allogeneic HCT) for treatment of pediatric Philadelphia chromosome-positive acute lymphoblastic leukemia (ALL)

BACKGROUND

Allogeneic hematopoietic cell transplant (HCT) with best available donor for children with Philadelphia positive (Ph+) acute lymphoblastic leukemia (ALL) has previously been considered standard practice. Since the introduction of imatinib into the treatment of this disease, the role of allogeneic HCT is more uncertain.

PROCEDURE

We investigated the impact of remission status, graft source, and imatinib use on transplant outcomes for 37 children with Ph+ ALL who received an allogeneic HCT at the University of Minnesota between 1990 and 2006. The median age at HCT was 7.47 (range; 1.4-16.4) years. Thirteen patients received imatinib therapy pre- and/or post-HCT (imatinib group) and 24 patients, received either no imatinib (n = 23) or only post-HCT relapse (n = 1) (non-imatinib group).

RESULTS

There was no difference in disease-free survival (DFS) or relapse between the imatinib and non-imatinib groups at 3 years (62%/15% vs. 53%/26%; P = 0.99; 0.81, respectively). There was no significant difference in transplant outcomes between matched related donor or unrelated donor (umbilical cord blood or matched unrelated marrow) recipients whereas patients receiving allogeneic HCT in first remission (CR1) had superior DFS and less relapse compared to patients transplanted in >or=CR2 (71%/16% vs. 29%/36%; P = 0.01; P = 0.05).

CONCLUSIONS

Based on this retrospective analysis at a single institution, the use of imatinib either pre- and/or post-transplant does not appear to significantly impact outcomes for children with Ph+ ALL and allogeneic HCT with the best available donor should be encouraged in CR1.

Impact of age, leukocyte count and day 21-bone marrow response to chemotherapy on the long-term outcome of children with philadelphia chromosome-positive acute lymphoblastic leukemia in the pre-imatinib era: results of the FRALLE 93 study

BACKGROUND

We explored the heterogeneity of philadelphia chromosome-positive acute lymphoblastic leukemia (Ph1-ALL) in a study of the effect of early features on prognosis in children. Here we report the long-term results of the FRALLE 93 study conducted in the era before the use of tyrosine kinase inhibitors.

METHODS

Between 1993 and 1999, 36 children with Ph1-ALL were enrolled into the FRALLE 93 protocol. After conventional four-drug induction, children were stratified by availability of an HLA-matched sibling.

RESULTS

Complete remission (CR) was observed in 26 children (72%), of which 13 underwent allogeneic bone marrow transplantation (BMT). Thirty-one children were good responders to prednisone, defined on day 8, and 21 were good responders to chemotherapy, defined by day-21 bone marrow (M1). Overall five-year disease-free survival (DFS) was 42 +/- 9.7%. Based on multivariate analysis, two groups showed marked differences in five-year outcome: children with age<10, leukocyte count <100,000/mm3 and day-21 M1 marrow had a more favorable prognosis (14 pts: 100% CR, event free survival [EFS]: 57%, overall survival [OS]: 79%), than the high-risk group (22 patients: 55% CR, EFS: 18%, OS: 27%) (p < 0.005). We also observed a non statistically significant difference (p = 0.14) in outcome between these groups for transplanted patients (5-year DFS: 83 +/- 14% and 33 +/- 15%, respectively).

CONCLUSION

Age, leukocyte count and early response to treatment defined by the D21 bone marrow response provide an accurate model for outcome prediction. The combination of available tools such as minimal residual disease assessment with determination of these simple factors could be useful for refining indications for BMT in the current era of tyrosine-kinase inhibitor-based therapy.

Allo-hematopoietic cell transplantation for Ph chromosome-positive ALL: impact of imatinib on relapse and survival

The utility of imatinib in either the pre- or post-transplant period for Ph chromosome-positive (Ph+) ALL is uncertain. In addition, there have been recent concerns regarding imatinib and cardiac toxicity. We investigated the outcome of 32 patients with Ph+ ALL who received an allo-hematopoietic cell transplant (HCT) at the University of Minnesota between 1999 and 2006. The median age at HCT was 21.9 years (range: 2.8-55.2). All patients were conditioned with CY and TBI. GVHD prophylaxis was CsA based. Of the 32 patients, 15 received imatinib therapy pre- or post-HCT (imatinib group) and 17 patients received either no imatinib (n=11) or only after relapse (n=6) (non-imatinib group). Overall survival, relapse-free survival and relapse at 2 years was 61, 67 and 13% for the imatinib group as compared with 41, 35 and 35% for the non-imatinib group (P=0.19, 0.12 and 0.20, respectively). Cardiac toxicity and TRM at 2 years were similar between groups. Thus, patients treated with imatinib in either the pre- or post-transplant setting had trends toward improved outcomes and no increase in cardiac toxicity. We suggest that imatinib be included in the peri-transplant management of all patients with Ph+ ALL.

Methylation status of Wnt signaling pathway genes affects the clinical outcome of Philadelphia-positive acute lymphoblastic leukemia

The clinical significance of aberrant promoter methylation of the canonical Wnt pathway antagonist genes (sFRP1, sFRP2, sFRP4, sFRP5, Wif1, Dkk3, and Hdpr1) and also putative tumor-suppressor gene Wnt5a, belonging to the non-canonical Wnt signaling pathway, was investigated in a large series of 75 patients with Philadelphia chromosome-positive acute lymphoblastic leukemia by methylation-specific polymerase chain reaction. At least one methylated gene was observed in cells from 66% (49/75) of patients (methylated group). Disease-free survival and overall survival at 9 years were 51 and 40%, respectively, for the unmethylated group and 3 and 2%, respectively, for the methylated group (both P < 0.0001). Multivariate analysis demonstrated that the Wnt methylation profile was an independent prognostic factor predicting disease-free survival (P = 0.007) and overall survival (P = 0.039). Abnormal DNA methylation of promoter-associated CpG islands in the Wnt signaling pathway is very common in Philadelphia chromosome-positive acute lymphoblastic leukemia and potentially defines subgroups with distinct clinical characteristics.

Alternative donor transplants for adult acute lymphoblastic leukaemia: a comparison of the three major options

Myeloablative sibling-matched allogeneic transplantation for adult acute lymphoblastic leukaemia provides the best outcome, but most patients lack a suitable, related histocompatible donor. We reviewed three haematopoietic stem cell donor sources used for alternative donor transplantation pointing out drawbacks of these approaches including inherent selection bias. Matched unrelated donor allografts most often are performed in Philadelphia chromosome-positive disease and in second complete remission (CR2); a nearly 30% event-free survival (EFS) can be anticipated in select patients. Transplants using haploidentical donors are most successful if undertaken in CR1 and CR2 and appear to produce EFS rates of about 25%. Limited umbilical cord blood transplant data suggest efficacy, but marked patient and treatment heterogeneity hamper conclusions. Each of these three strategies has unique potential benefits and disadvantages. The growing use of minimal residual disease detection may identify subgroups of patients unlikely to be cured by chemotherapy alone; these patients are candidates for upfront high-dose chemoradiotherapy and cellular immunotherapy. These three approaches are plagued by treatment-related mortality and relapse rates as high as 40%, but advances in technology and supportive care may make each stem cell source more feasible and efficacious.

NCI Thesaurus: a semantic model integrating cancer-related clinical and molecular information

Over the last 8 years, the National Cancer Institute (NCI) has launched a major effort to integrate molecular and clinical cancer-related information within a unified biomedical informatics framework, with controlled terminology as its foundational layer. The NCI Thesaurus is the reference terminology underpinning these efforts. It is designed to meet the growing need for accurate, comprehensive, and shared terminology, covering topics including: cancers, findings, drugs, therapies, anatomy, genes, pathways, cellular and subcellular processes, proteins, and experimental organisms. The NCI Thesaurus provides a partial model of how these things relate to each other, responding to actual user needs and implemented in a deductive logic framework that can help maintain the integrity and extend the informational power of what is provided. This paper presents the semantic model for cancer diseases and its uses in integrating clinical and molecular knowledge, more briefly examines the models and uses for drug, biochemical pathway, and mouse terminology, and discusses limits of the current approach and directions for future work.

Cord blood transplant in childhood ALL

BACKGROUND

Optimal therapy for high risk and relapsed acute lymphoblastic leukemia (ALL) remains uncertain. Wider availability of cord blood from related and unrelated donors has prompted studies of its use for hematopoietic stem cell transplant (HSCT).

PROCEDURE

We evaluated 26 consecutive cord blood transplants (CBT) for ALL performed at our center from 1996 to 2002 on studies using consistent conditioning therapy and graft-versus-host disease (GVHD) prophylaxis. Median patient age was 8.5 years (range, 0.5-24 year). Cord blood (CB) was from unrelated donors in 25/26 cases. Median CB nucleated cell dose was 3.26e7/kg (range, 0.8-12.9).

RESULTS

With median follow-up of 548 days, 16/26 patients (62%) are event-free survivors. Acute GVHD developed in 14/24 evaluable patients, reaching grade III-IV in 7 patients. Chronic GVHD occurred in 10/22 evaluable patients. Multivariate analysis showed higher total nucleated cell dose per kilogram to be the strongest predictor of event-free survival.

CONCLUSIONS

We conclude that CBT can effectively treat ALL in children with high risk features and following relapse.

Philadelphia positive acute lymphoblastic leukaemia of childhood

On current chemotherapeutic regimens, children with Philadelphia positive acute lymphoblastic leukaemia show a heterogeneous response to treatment. A few respond quickly to treatment and achieve long-term remission. Some fail to achieve remission after induction and the majority respond slowly to treatment. Relapse on treatment is common and remission is sustained in a proportion of cases only after allogeneic stem cell transplantation (allo-SCT). The use of imatinib along with conventional cytoreductive therapy, prior to allo-SCT appears to be the most promising strategy. The future lies in the molecular evaluation of response to treatment and combination targeted chemotherapy.

Acute leukemia of childhood: A single institution's experience

The aim of this study was to investigate distribution of immunophenotypic and cytogenetic features of childhood acute leukemia (AL) in the cohort of 239 newly diagnosed patients registered at the leading pediatric oncohematology center in the country during a six-year period (1996-2002). With approximately 60-70% of all childhood AL cases in Serbia and Montenegro being diagnosed and treated in this institution the used data represent a valid research sample to draw conclusions for entire country. On the basis of five phenotypic markers, the distribution of immunological subtypes was as follows: 169 (70.7%) expressed B-cell marker CD19 (137 were CD10 positive and 32 CD10 negative), 37 (15.5%) belonged to T-lineage acute lymphoblastic leukemia (T-ALL) (cyCD3 positive), and 33 (13.8%) were acute myeloblastic leukemia (AML) (CD13 positive and/or CD33 positive in the absence of lymphoid-associated antigens). The ratio of males and females was 1.5:1. Most of the cases were between the ages of 2 and 4, and were predominantly B-lineage acute lymphoblastic leukemia (B-ALL) cases. Another peak of age distribution was observed at the age of 7. The frequency of T-ALL (18% of ALL) was similar to that reported for Mediterranean countries: France (19.4%), Greece (28.1%), Southern Italy (28.3%), and Bulgaria (28.0%). Cytogenetic analyses were performed in 193 patients: 164 ALL and 29 AML. Normal karyotype was found in 57% of ALL and in 55% of AML patients, while cytogenetic abnormalities including structural, numerical, and complex chromosomal rearrangements were found in 43% of ALL and in 45% of AML patients. Our results represent a contribution to epidemiological aspects of childhood leukemia studies.

International Collaboration on Childhood Leukemia

The current cure rate of childhood acute lymphoblastic leukemia has reached 80% in many industrialized countries, but in developing countries the rate is often less than 10%. To advance the cure rate, investigators have formed several parallel initiatives in both industrialized and developing countries through international collaboration and partnership. Among industrialized countries, investigators have combined data to conduct in-depth studies of the biology and heterogeneity of high-risk or drug-resistant subgroups of leukemia to identify optimal or novel treatments. Alliances have been established among government, local nongovernmental organizations, health care providers, and international groups to improve the survival rate of childhood leukemia in developing countries. "Twinning" partnerships between a well-established individual institution or study group and a pediatric cancer unit in a developing country has proved to be the most successful strategy to date.

Allogeneic bone marrow transplantation vs chemotherapy for children with Philadelphia chromosome-positive acute lymphoblastic leukemia

Allogeneic bone marrow transplant (BMT) with an MRD in complete remission (CR)1 is the preferred treatment for children with Philadelphia-positive (Ph(+)) ALL. The role of MUD BMT in CR1 is still controversial. We compared the outcomes of two treatment strategies: BMT using an MRD or MUD vs chemotherapy in children with Ph(+) ALL in CR1. In total, 21 children were treated from 1985 to 2001. In all, 10 received chemotherapy and 11 received allogeneic BMT: four MRD, seven MUD. In the MRD group, one relapsed 12 months after BMT and died; the remaining three are long-term event-free survivors (median follow-up, 6.1 years). In the MUD group four died; the remaining three are long-term event-free survivors (median follow-up, 7.2 years). The 4-year event-free survival (EFS) for the BMT group was 53+/-15%. In the chemotherapy group, seven relapsed after a median period of 12.5 months and three remain in continuous CR (median follow-up, 2.4 years). Four chemotherapy patients received CR2 transplants; all died. The 4-year EFS for the chemotherapy and MUD groups was 33+/-17 and 35.7+/-20%, respectively. This difference was not statistically significant. We continue to support treating children with Ph(+) ALL with MRD BMT in CR1. The effectiveness of MUD BMT vs chemotherapy merits further study.

Prospective molecular monitoring of BCR/ABL transcript in children with Ph+ acute lymphoblastic leukaemia unravels differences in treatment response

Children with Philadelphia-chromosome-positive (Ph+) acute lymphoblastic leukaemia (ALL) represent a subgroup at very high risk for treatment failure, despite intensive chemotherapy. However, recent retrospective studies showed that Ph+ childhood ALL is a heterogeneous disease with regard to treatment response. We have prospectively monitored, by reverse transcription polymerase chain reaction (RT-PCR) during follow-up, the presence of the BCR/ABL fusion transcript in Ph+ ALL children diagnosed in the Italian multicentre Associazione Italiana Ematologia Oncologia Pediatrica ALL-AIEOP-95 therapy protocol. To our knowledge, this is the first report on the evaluation of minimal residual disease (MRD) in childhood Ph+ ALL prospectively enrolled in an intensive, Berlin-Frankfurt-Munster (BFM)-type treatment protocol. Twenty-seven of 36 (75.0%) Ph+ patients consecutively enrolled into the high-risk group of the AIEOP-ALL protocol between May 1995 and October 1999 were successfully analysed. Twenty were good responders to the pre-phase of prednisone/intrathecal methotrexate treatment (PGR) and seven were poor responders (PPR). Within the PPR group, the RT-PCR monitoring constantly showed positivity for the BCR/ABL fusion transcript and all the patients died of disease progression. In contrast, highly sensitive qualitative RT-PCR monitoring revealed heterogeneity within the PGR group of Ph+ childhood ALL patients. Three different subgroups could be defined, according to the clearance of Ph+ cells within the first 5 months of treatment. This provides useful information on the capability of chemotherapy to reduce the leukaemic clone, with prognostic implications.

In vitro drug resistance profile of Philadelphia positive acute lymphoblastic leukemia is heterogeneous and related to age: a report of the Dutch and German Leukemia Study Groups

BACKGROUND

The t(9;22)(q34;q11) translocation leading to the Philadelphia (Ph) chromosome resulting in BCR-ABL gene fusion is associated with a poor prognosis in acute lymphoblastic leukemia (ALL).

PROCEDURE

We studied the relation between t(9;22), determined by karyotype, fluorescence in situ hybridization (FISH) or polymerase chain reaction (PCR), and in vitro drug resistance, measured by the MTT assay, in precursor B-cell ALL at diagnosis. The findings in twenty-one Ph-positive (Ph+) childhood common/precursorB (c/preB) cases were compared with 254 Ph-negative (Ph-) ALL cases.

RESULTS

A large range of LC(50) values was found within the Ph+ patients. Moreover, LC(50) values did not differ significantly between Ph+ and Ph- samples for prednisolone, dexamethasone, L-asparaginase, vincristine, anthracyclines, thiopurines, epipodophyllotoxins, and 4H00-ifosfamide, even after matching for important prognostic features (age, white blood cell count (WBC), and immunophenotype). Adult Ph+ (n = 12) ALL was more resistant to prednisolone (> 270-fold, P = 0.030), and displayed an overall tendency to resistance when compared to matched cases of Ph- (n = 15) adult precursor B-cell ALL. Within Ph+ ALL, in vitro prednisolone resistance increased significantly with age (P = 0.006). The expression of lung resistance protein (LRP), but not P-glycoprotein (P-gp) or multidrug resistance protein (MRP), was significantly higher in all Ph+ patients.

CONCLUSIONS

Both childhood and adult Ph+ precursor B-cell ALL samples display a heterogeneous in vitro resistance profile, with relatively sensitive and resistant cases. The adult Ph+ samples, however, are generally more resistant compared to matched Ph- controls, reaching significance for prednisolone. The correlation of prednisolone resistance with age within the Ph+ cases might help explain the poorer prognosis of adult Ph+ ALL.

Philadelphia chromosome-positive acute lymphoblastic leukemia- current concepts and future perspectives

Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) is diagnosed rarely in children, but constitutes the most frequent cytogenetic abnormality in adults with ALL. In contrast to chronic myeloid leukemia (CML), patients with Ph-positive ALL usually demonstrate expression of a truncated version of the BCR-ABL protein called p190bcr-abl. Irrespective of age and breakpoint location, Ph-positive ALL carries a poor prognosis. Although remission rates are identical to those of Ph-negative ALL, relapse is almost universal and long-term survival remains rare. Given the poor outcome with current chemotherapy consolidation programs, stem cell transplantation is usually recommended for these patients in first remission or as soon as feasible. Even with transplantation the impact on outcome is limited and new therapeutic concepts are urgently needed. One of the most promising developments in recent years has been the introduction of the tyrosine kinase inhibitors such as STI571. An overview of current treatment modalities in Ph-positive ALL will be provided and the rationale for new therapies will be discussed.

Molecular measurement of minimal residual disease in Philadelphia-positive acute lymphoblastic leukaemia

The Philadelphia chromosome (Ph) is found in approximately 5-25% of acute lymphoblastic leukaemia (ALL) cases and is the harbinger of a poor outcome. Polymerase chain reaction (PCR) assays can detect leukaemia-specific genetic lesions down to a sensitivity approaching one leukaemia cell in a background of a million normal cells. In Ph(+) ALL, the unique BCR-ABL translocation is thus a specific target for the detection of minimal residual disease (MRD). After chemotherapy or transplantation the detection of residual BCR-ABL transcripts is associated with a high risk of subsequent relapse. With the advent of novel therapeutics that target the structure and function of BCR-ABL, the detection of MRD may allow for targeted therapy that could abort a potential relapse.

Treatment of adult acute lymphoblastic leukemia (ALL): long-term follow-up of the GIMEMA ALL 0288 randomized study

The GIMEMA ALL 0288 trial was designed to evaluate the impact of a 7-day prednisone (PDN) pretreatment on complete remission (CR) achievement and length, the influence of the addition of cyclophosphamide (random I) to a conventional 4-drug induction on CR rate and duration, and whether an early post-CR intensification (random II) by an 8-drug consolidation could improve CR duration. Median follow-up of this study was 7.3 years. From January 1988 to April 1994, among 794 adult (> 12 but < 60 years) patients registered, 778 were eligible. Their median age was 27.5 years; 73% had B-lineage acute lymphoblastic leukemia (ALL) and 22% had T-lineage disease; 18% showed associated myeloid markers; 47 of 216 analyzed patients (22%) had Philadelphia chromosome-positive ALL. Response to PDN pretreatment was observed in 65% of cases. CR was achieved in 627 patients (82%). Resistant patients and induction death rates were 11% and 7%, respectively. Random II was applied to 388 patients with CR; 201 had maintenance alone and 187 had consolidation followed by maintenance. The relapse rate was 60%; isolated central nervous system relapses were 8% of all CRs and 13% of all relapses. Median survival (overall survival [OS]), continuous complete remission (CCR), and disease-free survival (DFS) were 2.2, 2.4, and 2 years, respectively. PDN pretreatment response resulted the main independent factor influencing CR achievement, OS, CCR, and DFS; the addition of cyclophosphamide in induction significantly influenced CR achievement in a multivariate analysis. Neither induction intensification nor early consolidation appeared to influence CCR and DFS duration. For the first time PDN pretreatment response proved to be a powerful factor predicting disease outcome in adult ALL patients.

Allogeneic transplantation for leukaemia using unrelated donors

This chapter describes the current role of unrelated donor stem cell transplantation (UD-SCT) in the management of leukaemia. The available data are scant and incomplete and there are few randomized studies comparing UD-SCT with alternative therapies. Patients with many of the leukaemias require prolonged follow-up after allogeneic SCT to determine whether they are cured; the registry-based comparisons that have been initiated reflect the results achievable some years ago and may not help us in deciding what is best in 2001. In addition, new therapies such as ST1571, even though the long-term outcome of patients treated with this agent is uncertain, may affect which patients with chronic myeloid leukaemia we decide to recommend for transplant. The focus here is on acute and chronic myeloid leukaemia, acute lymphoblastic leukaemia and chronic lymphocytic leukaemia, as well as the myelodysplastic syndromes. Patient selection, conditioning strategies, comparison with other therapies, timing of transplant and the major causes of treatment failure are discussed, and there is an exploration of where improvement will come from.

Allogeneic bone marrow transplantation in first remission rescues children with Philadelphia chromosome-positive acute lymphoblastic leukemia: Tokyo Children's Cancer Study Group (TCCSG) studies L89-12 and L92-13

BACKGROUND

The prognosis of Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph(+) ALL) is generally poor and reports from large studies are scarce. We evaluated the efficacy of allogeneic bone marrow transplantation (allo-BMT) for children with this type of leukemia.

PROCEDURE

The chemotherapy regimens consisted of an induction phase and very intensive consolidation followed by a reinduction phase and late intensification treatment. The selection of treatment modalities such as chemotherapy, allo-BMT, or autologous transplantation was made by each institute. The principal endpoint was the outcome of children with Ph(+) ALL according to the treatment options.

RESULTS

Thirty-two patients (4.3%) were diagnosed as Ph(+) ALL out of the 741 cases of ALL consecutively enrolled in two protocols of the Tokyo Children's Cancer Study Group (TCCSG) from 1989 to 1994. Thirty patients (93.8%) were induced into complete remission (CR). Of these 30 patients, eight children electively received allo-BMT in the first CR. Six of these patients are in continuous remission at a median follow-up of 58 (range 48-105) months after the diagnosis. One patient died following recurrence and another patient died of graft vs. host disease. Three patients treated with autologous BMT or peripheral blood stem cell transplantation in the first CR experienced a subsequent relapse. In the remaining 19 patients, 13 patients were treated with very high-risk chemotherapy alone and all relapsed within 28 months. One patient was excluded from the analysis because he was treated with standard-risk chemotherapy until relapse. The other five patients were also excluded from the analysis because Philadelphia chromosome was not detected until they relapsed. None of the relapsed patients survived in spite of treatment including allo-BMT. In multivariate analysis, only allo-BMT remained as an independent factor for good prognosis.

CONCLUSIONS

The only way to cure children with Ph(+) ALL was allo-BMT in this study and its outcome seemed promising.

Childhood leukemia: Understanding the significance of chromosomal abnormalities

The survival for children with acute lymphoblastic leukemia (ALL) has increased from 3% to greater than 70% in the last 30 years, with some patients achieving 95% survival. These advances have been made not only because therapy has improved, but also because there is a much greater understanding of the diversity of ALL. The identification of clinical and biological prognostic factors associated with ALL has resulted in the formation of subsets of patients classified into risk groups. Although age, initial white blood cell count, and central nervous system or testicular disease are all important prognostic factors, cytogenetic abnormalities have now emerged as the single most important prognostic factor for children with ALL. There are specific cytogenetic findings in the leukemic blast cells of these children that influence their prognosis. Some of these findings are positive factors and some adverse. Treatment protocols for ALL today are now determined by these specific chromosomal abnormalities.

The role of prognostic features in the treatment of childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common cancer in children and is among the most curable of the pediatric malignancies. Many clinical, biological, genetic, and molecular features have been identified as having prognostic significance in the outcome of patients with ALL. The standard features are age and WBC at diagnosis, with infants (less than one year), adolescents (greater than nine years), and children with WBC above 50,000/microl being at higher risk. Certain chromosomal abnormalities are also strong predictors; in particular, the Philadelphia chromosome and MLL gene rearrangements (especially in infants) are adverse features, while TEL-AML1 is favorable. It is important to note, however, that even the most important known predictors explain only a small proportion of the variability in outcome. These features are currently used to tailor the intensity of treatment so that the toxicity of treatment can be minimized and cure rates can continue to improve. This article reviews time-honored prognostic features, recent advances, and future directions in this field.

Philadelphia chromosome-positive acute lymphocytic leukemia

On a molecular and cellular level, Ph+ ALL seems to be a heterogeneous disease. Unfortunately, the unifying theme of Ph positivity is the poor outcome associated with its presence. Further characterization of molecular subtypes of Ph+ ALL may in the future distinguish those few patients with a potentially good outcome from the majority who face inevitable relapse. Also, novel targeted biologic therapy especially in combination with aggressive, early chemotherapy, may soon be able to temper the disease. Most patients who obtain a remission would be best served by transplantation during remission. For those without a donor, following the disease by PCR-based techniques may detect early relapse. For relapsed patients without the option of transplantation, investigative studies are appropriate.

Long-term results of Total Therapy studies 11, 12 and 13A for childhood acute lymphoblastic leukemia at St Jude Children's Research Hospital

We present the long-term results of three consecutive clinical trials (Total Therapy studies 11, 12 and 13A) conducted for children with newly diagnosed acute lymphoblastic leukemia (ALL) between 1984 and 1994. In study 11 (1984-1988), the overall event-free survival rates (+/-1 s.e.) were 71.8 +/- 2.4% and 69.3 +/- 2.4%, and the cumulative risks of isolated central nervous system (CNS) relapse 5.6 +/- 1.2% and 5.9 +/- 1.3%, at 5 and 10 years, respectively. In study 12 (1988-1991), event-free survival rates were 67.6 +/- 3.4% and 61.5+/- 9.0%, and isolated CNS relapse rates were 10.4 +/- 2.3% and 10.4 +/- 2.3%, respectively. Early intensive intrathecal therapy in study 13A (1991-1994) has yielded a very low 5-year isolated CNS relapse rate of 1.2 +/- 0.9%, boosting the 5-year event-free survival rate to 76.9 +/- 3.3%. Factors consistently associated with an adverse prognosis included male sex, infant or adolescent age group, leukocyte count >100 x 10(9)/l, nonhyperdiploidy karyotype and poor early response to treatment. Risk classification based on age and leukocyte count had prognostic significance in B-lineage but not T-lineage ALL. Early therapeutic interventions or modifications for patients with specific genetic abnormalities or persistent minimal residual leukemia may further improve long-term results.

Bone marrow transplantation versus chemotherapy in the treatment of very high–risk childhood acute lymphoblastic leukemia in first remission: results from Medical Research Council UKALL X and XI

The role of bone marrow transplantation (BMT) in first remission of children with high-risk acute lymphoblastic leukemia (ALL) remains unclear. There were 3676 patients (aged 1 to 15 years) entered into the United Kingdom (UK) Medical Research Council (MRC) trials UKALL X and XI from 1985 to 1997. Of these patients, 473 patients (13%) were classified as very high (VH) risk and were eligible for a transplantation from a matched histocompatible sibling donor (MSD). We tissue-typed 286 patients; 99 patients had a matched related donor, and 76 patients received transplantations. Additionally, 25 children received transplantations from a matched unrelated donor (MUD) despite trial guidelines for MSD transplantations only. The median time to transplantation was 5 months (range, 2 to 19 months), and the median follow-up was 8 years. The 10-year event-free survival (EFS) adjusted for the time to transplantation, diagnostic white blood cell (WBC) count, Ph chromosome status, and ploidy was 6.0% higher (95% confidence interval (CI), −10.5% to 22.5%) for 101 patients who received a first-remission transplantation (MSD and MUD) than for the 351 patients treated with chemotherapy (transplantation, 45.3%, vs chemotherapy, 39.3%). The transplantation group had fewer relapses (31%) compared to relapses in the chemotherapy group (55%); however, the transplantation group had more remission deaths (18%) compared to remission deaths in the chemotherapy group (3%). In contrast the adjusted 10-year EFS was 10.7% higher (95% CI, −2.6% to 24.0%) for patients without a human leukocyte antigen (HLA)–matched donor than for those patients with a donor (no donor, 50.4%, vs donor, 39.7%). In conclusion, for the majority of children with VH-risk ALL, the first-remission transplantation has not improved EFS.

Bone marrow transplantation versus chemotherapy in the treatment of very high–risk childhood acute lymphoblastic leukemia in first remission: results from Medical Research Council UKALL X and XI

The role of bone marrow transplantation (BMT) in first remission of children with high-risk acute lymphoblastic leukemia (ALL) remains unclear. There were 3676 patients (aged 1 to 15 years) entered into the United Kingdom (UK) Medical Research Council (MRC) trials UKALL X and XI from 1985 to 1997. Of these patients, 473 patients (13%) were classified as very high (VH) risk and were eligible for a transplantation from a matched histocompatible sibling donor (MSD). We tissue-typed 286 patients; 99 patients had a matched related donor, and 76 patients received transplantations. Additionally, 25 children received transplantations from a matched unrelated donor (MUD) despite trial guidelines for MSD transplantations only. The median time to transplantation was 5 months (range, 2 to 19 months), and the median follow-up was 8 years. The 10-year event-free survival (EFS) adjusted for the time to transplantation, diagnostic white blood cell (WBC) count, Ph chromosome status, and ploidy was 6.0% higher (95% confidence interval (CI), −10.5% to 22.5%) for 101 patients who received a first-remission transplantation (MSD and MUD) than for the 351 patients treated with chemotherapy (transplantation, 45.3%, vs chemotherapy, 39.3%). The transplantation group had fewer relapses (31%) compared to relapses in the chemotherapy group (55%); however, the transplantation group had more remission deaths (18%) compared to remission deaths in the chemotherapy group (3%). In contrast the adjusted 10-year EFS was 10.7% higher (95% CI, −2.6% to 24.0%) for patients without a human leukocyte antigen (HLA)–matched donor than for those patients with a donor (no donor, 50.4%, vs donor, 39.7%). In conclusion, for the majority of children with VH-risk ALL, the first-remission transplantation has not improved EFS.

Outcome of treatment in children with Philadelphia chromosome-positive acute lymphoblastic leukemia

BACKGROUND

Children with Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph-positive ALL) have a poor prognosis, and there is no consensus on the optimal treatment for this variant of ALL.

METHODS

We reviewed the medical records of patients with Ph-positive ALL who were treated with intensive chemotherapy, with or without bone marrow transplantation, by 10 study groups or large single institutions from 1986 to 1996. Data on 326 children and young adults, who ranged in age from 0.4 to 19.9 years (median, 8.1), were analyzed to determine the rate of complete remission and the probability of event-free, disease-free and overall survival according to standard prognostic factors and type of treatment.

RESULTS

The 267 patients who achieved a complete remission after induction chemotherapy (82 percent) were stratified into three subgroups according to the age and leukocyte count at the time of diagnosis: those with the best prognosis (a leukocyte count of less than 50,000 per cubic millimeter and an age of less than 10 years; 95 patients); those with an intermediate prognosis (intermediate-risk features; 92 patients); and those with the worst prognosis (a leukocyte count of more than 100,000 per cubic millimeter; 80 patients). The estimates of disease-free survival at five years (+/-SE) were 49+/-5 percent) for patients with the best prognosis), 30+/-5 percent (for those with an intermediate prognosis), and 20+/-5 percent (for those with the worst prognosis) (P<0.001 for the overall comparison). We also found that transplantation of bone marrow from an HLA-matched related donor offered significantly greater benefit than intensive chemotherapy alone in terms of protecting patients from relapse or other adverse events (relative risk, 0.3; 95 percent confidence interval, 0.2 to 0.5; P<0.001). This finding was consistent in all three groups.

CONCLUSIONS

Unlike the usual type of all, Ph-positive ALL is associated with a poor prognosis. Nevertheless, in some patients with favorable prognosis features, the disease can be be controlled by intensive chemotherapy. Transplantation of bone marrow from an HLA-matched related donor is superior to other types of transplantation and to intensive chemotherapy alone in prolonging initial complete remissions.

Outcome of Philadelphia chromosome-positive adult acute lymphoblastic leukemia

Philadelphia chromosome (Ph)-positive acute lymphoblastic leukemia (ALL) represents the most common cytogenetic abnormality in adult ALL. It is found in 15% to 30% of patients, and its incidence increases with age. As in children, prognosis in Ph-positive adult ALL is poor. No therapeutic approach has had substantial impact on its unfavorable course. We analyzed the characteristics and outcome of newly diagnosed adults with Ph-positive ALL treated at the M. D. Anderson Cancer Center between 1980 and 1997. The diagnosis of patients was based on typical morphological and immunophenotypic criteria of marrow aspirate and biopsy specimens. Cytogenetic and molecular studies were also performed. A total of 67 patients were included in this study. From 1980 until 1991, 38 patients with Ph-positive ALL were treated with vincristine, Adriamycin, and dexamethasone (VAD), or with acute myeloid leukemia (AML)-like induction protocols. Since 1992 a total of 29 patients received induction therapy with an intensified treatment protocol, called "hyper-CVAD". The outcome of patients treated with standard and intensified treatment regimens was compared and results of our institution contrasted with data obtained from other centers. Ph-positive ALL was present in 67 of 498 patients with newly diagnosed ALL (13%). Patients with Ph-positive ALL had a higher median age (44 versus 34, P=0.007), higher median white blood cell (WBC) counts at presentation (25 versus 8, P=0.0002), and higher peripheral median percentage of blast counts (63 versus 40, P=0.023). FAB subtype L2 (70% versus 49%, P=0.001) and CALLA-positive pre-B immunophenotype (75% versus 37%, P<0.001) predominated among Ph-positive ALL. Myeloid marker coexpression was more frequent in Ph-positive ALL when compared with Ph-negative ALL (52% vs. 27% for CD13, P<0.001, and 44% vs. 27% for CD33, P=0.005). Among patients treated with hyper-CVAD, the complete remission (CR) rate was 90% versus 55% (P=0.002) with pre-hyper-CVAD regimens (VAD and AML-like induction protocols), the median CR duration was 43 weeks versus 32 weeks (P>0.5), median disease-free survival (DFS) was 42 weeks versus 29 weeks (P=0.008), and median survival was 66 weeks versus 45 weeks (P>0.5). Patients with hyperdiploid Ph-positive ALL on hyper-CVAD therapy achieved significantly longer CR duration and DFS than hypo- and pseudodiploid cases (59 weeks versus 42 and 31 weeks, P=0.02 and 0.04, respectively). In contrast, patients treated with regimens prior to hyper-CVAD had significantly shorter CR duration (21 weeks versus 33 and 29 weeks, P=0.03) and DFS with hyperdiploid karyotypes when compared to pseudodiploid and hypodiploid cases (16 weeks versus 30 and 13 weeks, P=0.008). In conclusion, our results demonstrate improved response rate and DFS with current intensive regimens (hyper-CVAD) in patients with Ph-positive ALL, but no advantage in overall survival.

A new complex variant Philadelphia chromosome, t(1;9;22)ins(17;22), characterized by fluorescence in situ hybridization in an adult ALL

A new complex variant Philadelphia chromosome was detected in a 65-year-old man with acute, pre-B, lymphoblastic leukemia (ALL). The classic cytogenetic analysis identified an apparently balanced three-way translocation t(1;9;22)(q25;q34;q11.2). Fluorescence in situ hybridization (FISH) studies confirmed the translocation and showed bcr/abl fusion on the der(22). However, these studies revealed that the distal part of the bcr gene was not translocated onto chromosome 1 at 1q25, but inserted into chromosome 17 at 17p12-13. This complex variant translocation was described as a t(1;9;22)(q25;q34;q11.2)ins(17;22)(p12-13;q11.2q11.2). Secondary changes including +8, an inversion of the derivative chromosome 9, a translocation t(14;20)(q11;q13), and an additional derivative 22 were also identified in most of the abnormal cells. The patient died from systemic fungemia and multiorgan failure 9 months after the diagnosis of ALL. The clinical significance of complex variant Philadelphia chromosomes in ALL is reviewed and discussed.

Clinical sensitivity to anthracyclines in PH/BCR+ acute lymphoblastic leukemia

Translocation t(9;22) or Philadelphia chromosome (Ph)/BCR-ABL rearrangement positive acute lymphoblastic leukemia (Ph/BCR+ ALL) is associated with a very short survival of about one year in most patients. We analyzed long-term outcome of 76 adults with Ph/BCR+ ALL, in order to detect which factors were associated with longer survival. Modifiable prognostic factors included type of treatment, allogeneic marrow transplant (allo-BMT), and early anthracycline dose intensity (high = H/A, low = L/A); unmodifiable factors were age, gender, FAB morphology, phenotype, blast count, P190/210 transcript, hepatospleno-lymphadenopathy, LDH level. Median patient age was 43 years (range 15-71). Four favorable prognostic factors (FPF) were found associated with greater likelihood of complete remission (blast count < 50 x 10(9)/l, p = 0.08), longer remission duration (age < 50 years, p < 0.001; H/A, p < 0.05), and lower relapse rate (allo-BMT, p = 0.017). Age and anthracycline dose intensity exerted a synergistic prognostic effect. According to the cumulative incidence of FPF in each patient (FPF 0-1 = 29, 2-3 = 42, 4 = 5), the probability of survival increased from nil to 0.22 to 0.60 at 5 years (p < 0.005). Adult Ph/BCR+ ALL is relatively sensitive to anthracyclines, which therefore should be prescribed at full dosage to patients not eligible to allo-BMT or in the waiting list for unrelated donor transplantation.

Acute lymphoblastic leukemia in India: an analysis of prognostic factors using a single treatment regimen

BACKGROUND

In the past, treatment results in Indian children with ALL have been poor, primarily due to inadequate chemotherapy and supportive care, but perhaps reflecting differences from Western countries in the pattern of subtypes. In an attempt to improve survival, we have used a more intensive treatment protocol, MCP841, and examined prognostic factors.

PATIENTS AND METHODS

Five hundred thirty previously untreated patients < 25 years of age with ALL were entered on study at the Tata Memorial Hospital, Mumbai. Treatment consisted of three successive induction cycles, consolidation and six maintenance cycles. CNS prophylactic therapy consisted of cranial irradiation (2000 cGy) for patients above two years and high-dose cytarabine for patients less than two years. The total treatment duration was two years.

RESULTS

Most patients had hepatosplenomegaly (80%) and or lymphadenopathy (79%) and 21% were of T-cell immunophenotype, but very few (1.3%) had CNS disease. CR was achieved in 484 (91.3%) patients and 145 (29.9%) patients relapsed. There were 36 induction deaths and 49 remission deaths, but the toxic death rate was significantly lower after 1990. In patients treated since 1990, three risk groups could be discerned: 1) WBC < 60,000 per mm3 and no lymphadenopathy (77% event-free survival (EFS) at five years): 2) WBC < 60,000 per mm3 with lymphadenopathy (53% EFS) or, WBC > 60,000 per mm3 and Hb 6 gm/dl or above (48% EFS): and 3) WBC > 60,000 per mm3 and Hb below 6 gm dl (16% EFS). In a multivariate model, only WBC, Hb and lymphadenopathy were significantly associated with EFS (P < 0.01).

CONCLUSIONS

The CR and EFS rates achieved represent a significant improvement over previous results at this institution. Bulky extramedullary disease was an important risk factor in this series, but age and WBC alone inadequately defined risk groups, suggesting that prognostic factors may vary in different world regions.

Genetic abnormalities and drug resistance in acute lymphoblastic leukemia

Recent advances in cytogenetics and molecular genetics have made it possible to identify an array of genomic abnormalities with prognostic and therapeutic significance. Hyperdiploidy > 50 chromosomes and ETV6-CBFA2 fusions have been used to identify low-risk cases, and BCR-ABL and MLL-AF4 to define high-risk leukemias. Despite their clinical utility, the risk classification system based on these findings lack absolute precision and should be complemented with other variables, the most important of which is the early blast cell response to remission induction therapy. Studies of tumor suppressor genes and proto-oncogenes in the BCL2 family genes may unravel the mechanisms of leukemia cell progression and the development of drug resistance, leading to innovative therapies. As the cure rates for childhood acute lymphoblastic leukemia (ALL) approach 80%, precise methods of risk assessment are needed to permit better selection of treatment that is neither excessive nor inadequate for individual patients. Because one or more genetic abnormalities underlie every case of leukemia, a risk assignment system based on primary genetic abnormalities has great intuitive appeal. Even though over 90% of childhood ALL cases can be readily classified according to numerical or gross structural chromosomal abnormalities, molecular analyses are essential to identify therapeutically relevant, submicroscopic genetic lesions not visible by karyotyping. This review focuses mainly on recent advances in genetic studies that have contributed to therapeutic advances or that hold promise for the future.

Molecular genetics of childhood leukemias

PURPOSE

This review summarizes the molecular genetics of childhood leukemias, with emphasis on pathogenesis and clinical applications.

DESIGN

We first describe the most common genetic events that occur in pediatric acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). We then illustrate how these molecular alterations may be used to alter therapy.

RESULTS

In childhood ALL, the TEL-AML1 fusion and hyperdiploidy are both associated with excellent treatment outcomes and therefore identify patients who may be candidates for less intensive therapy. In contrast, MLL gene rearrangements and the BCR-ABL fusion confer a poor prognosis; these patients may be best treated by allogeneic bone marrow transplantation in first remission.

CONCLUSIONS

Although clinical features are important prognostic indicators, genetic alterations of leukemic blasts may be better predictors of outcome for acute leukemia patients. We therefore favor risk-adapted therapy based on classification schemes that incorporate both genetic and clinical features.