Treatment of acute lymphoblastic leukaemia (ALL).

Forty-six consecutive patients with acute lymphoblastic leukaemia (ALL), having a median age of 23 years (range 14 to 64), underwent induction and consolidation chemotherapy with weekly parenteral vincristine, adriamycin, l-asparaginase and daily oral prednisone (VAAP), followed by standard central nervous system (CNS) prophylaxis. Maintenance therapy was given for 3 years and consisted of daily 6-mercaptopurine, weekly methotrexate, and monthly intrathecal chemotherapy, with drug intensification comprising either vincristine, adriamycin and l-asparaginase (VAA) or cyclophosphamide, vincristine, cytosine arabinoside and prednisone (COAP). Complete remission (CR) was achieved in 36 patients (78%) and only the FAB L1 morphology was a significant predictive factor (Chi-squared = 3.91: p < 0.05). Eight of the 10 non-responders had significant drug resistance and 3 deaths were associated with marrow hypoplasia. Median follow-up is 52 months. Median duration of CR is 28 months, median survival of all patients is 16 months, and for those who achieved CR is 44 months. There was no difference between the two maintenance arms. Significant prognostic factors for survival are French-American-British (FAB) subtype, in which the L1 is better than L2 (p = 0.05), and age (p = 0.035). Nineteen patients have experienced medullary relapse and 7 (37%) achieved subsequent CR; this is durable in a single patient who underwent allogeneic bone marrow transplantation. Eight patients (17%) had CNS disease at diagnosis; 5 achieved CR and 1 is alive and disease-free at 65+ months. There has been 1 CNS relapse. These results demonstrate that prolonged remissions and survival can be achieved with this protocol and many patients possibly cured. The level of toxicity is acceptable and the pattern of induction failure indicates that a margin exists for intensifying chemotherapy and thereby possibly further improving results.     

Secondary acute lymphoblastic leukaemia is constitutional and probably not related to prior therapy

Very little is known about secondary acute lymphoblastic leukaemia (s‐ALL). This retrospective analysis studied a cohort of s‐ALL patients treated at a single centre between 1994 and 2013, while comparing therapy‐associated ALL (t‐ALL) and antecedent malignancy ALL (am‐ALL) patients. Thirty‐two patients with s‐ALL were identified. The overall incidence was 9·4% among ALL adults while T‐cell s‐ALL was rare (12% of s‐ALLs). The median time interval between two malignant diagnoses was 5·3 years (range: 0·1–28). In contrast to previous reports, most of the s‐ALLs were CD10 +  and without KMT2A (MLL) abnormalities. The overall survival (OS) rates of the entire cohort at 12 and 24 months from ALL diagnosis was 49% and 25%, respectively. Most patients (n = 23, 72%) received prior chemo‐/radio‐therapy for their first malignancy (t‐ALL) and only 9 (28%) did not (am‐ALL). No significant difference was found in the incidence of B‐/T‐ lineage ALL, extramedullary disease, blood count, and the rate of Philadelphia‐positive ALL, nor in the rates of complete remission (P = 0·55) and OS (P = 0·97). This similarity, together with high incidence of family malignancy in both groups, raise the possibility that s‐ALL patients may have an inherent predisposition to malignancies and a history of previous therapy may be of lesser importance in the pathogenesis of s‐ALL.     

Personal practice: how we manage the risk of bleeding and thrombosis in children and young adults with acute lymphoblastic leukaemia

Bleeding and thrombosis are not infrequent problems in children receiving treatment for acute lymphoblastic leukaemia (ALL). The exact frequency varies with age, co-morbidity and treatment schedule, but the risk is highest in the first few weeks of treatment when disease and treatment-related haemostatic abnormalities prevail. Recommendations for prevention and management are lacking due to a weak evidence base, resulting in considerable variation in practice. This article describes our personal practice in this area with reference to the available literature on the subject.     

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.     

Prognostic factors in adult acute lymphoblastic leukaemia

Treatment of acute lymphoblastic leukaemia (ALL) in adults presents a formidable challenge. While overall results have improved over the past 3 decades, the long‐term survival for patients aged less than 60 years is only in the range of 30–40% and is 10–15% if between 60 and 70 years and <5% for those over 70 years. The historic lack of clear‐cut biological prognostic factors has led to over‐ or under‐treatment of some patients. Response to initial therapy is an important prognosticator of outcome based on disease biology, as well as pharmacogenetics, which include the patient’s response to drugs given. The more widespread availability of allogeneic transplantation and reduced‐intensity regimens for older patients have opened up this curative modality to a greater number of patients. Hopefully, those options, as well as novel cytogenetic and molecular markers, will enable a better selection of patients who undergo intensive therapies and finally break the 30–40% cure barrier for adults with ALL.     

Down syndrome and acute lymphoblastic leukaemia

Acute lymphoblastic leukaemia in children with Down syndrome (ALL-DS) is characterised by unique clinical and biological features. Notable among these are an absence of ALL in DS patients <1 year of age; a lower incidence of favourable and unfavourable chromosomal translocations; heightened sensitivity to methotrexate; and an increased propensity to infections. Although children with ALL-DS have historically fared less well than their non-DS counterparts (ALL-NDS), recent data indicate that outcomes in ALL-DS are now comparable with ALL-NDS with risk-adapted therapies, after adjusting for biological differences between the ALL-DS and ALL-NDS populations. Given the increased risk of ALL-DS patients for treatment-related toxicities, further intensification of therapy may not yield continued improvements in survival. Future investigations in the ALL-DS population should focus on maintaining excellent outcomes while reducing treatment-related complications through novel treatment strategies, such as the integration of targeted noncytotoxic agents.     

Intraocular relapse of childhood acute lymphoblastic leukaemia

Relapse of childhood acute lymphoblastic leukaemia (ALL) involving the eye is a rare but challenging problem. Twenty cases occurred in patients treated on the Medical Research Council United Kingdom Acute Lymphoblastic Leukaemia XI and ALL97 trials between 1991 and 2001, representing 2.2% of ALL relapses. Seventeen occurred as a first relapse, either in isolation or combined with relapse at another site, and three occurred as a second relapse. All patients with intraocular disease at first relapse were treated with both chemotherapy and radiotherapy, but the doses and protocols used varied. Eleven of these 17 patients are alive and in complete remission with a median follow up of 4 years 2 months from relapse. All 11 children that were treated with a full chemotherapy relapse protocol, together with local radiotherapy have survived. Patients treated with chemotherapy of shorter duration and intensity, despite radiotherapy and/or bone marrow transplantation, did poorly with only one survivor, currently in chronic relapse. Consequently, we suggest that children with eye relapse of ALL be treated with an intensive relapse chemotherapy protocol with local ocular radiotherapy, whether the relapse occurs in isolation or in combination with relapse at another site.     

Prognostic factors in elderly acute lymphoblastic leukaemia

A retrospective study was performed on 46 unselected acute lymphoblastic leukaemia (ALL) elderly patients aged 60 years or more. Only 50% of these patients were included in the EORTC cooperative clinical trials, thus confirming the important selection bias in most of the published series on elderly ALL patients. 43% of the elderly patients achieved a complete remission (CR). The median survival was 10 months and the 5-year overall survival was only 7.6±4%. In multivariate analysis, W.H.O. performance status and peripheral blast counts at day 7 were found to significantly influence achievement of CR and survival. In patients with W.H.O. performance status 2, 35% died during induction treatment versus 4% in patients with W.H.O. performance status <2. Patients >70 years old showed a marked drop of the CR rate (27%) compared to those aged 60–69 (67%), and a very high death rate during the induction period (38% versus 4%). This suggests that ALL protocol treatments should be proposed until 70 years in patients with good-performance status, whereas less intensive treatment should be offered to elderly patients with performance status 2 and/or age 70. Peripheral blast counts at day 7 may help to adjust the treatment during induction phase.     

Predicting relapse risk in childhood acute lymphoblastic leukaemia

Intensive multi‐agent chemotherapy regimens and the introduction of risk‐stratified therapy have substantially improved cure rates for children with acute lymphoblastic leukaemia (ALL). Current risk allocation schemas are imperfect, as some children are classified as lower‐risk and treated with less intensive therapy relapse, while others deemed higher‐risk are probably over‐treated. Most cooperative groups previously used morphological clearance of blasts in blood and marrow during the initial phases of chemotherapy as a primary factor for risk group allocation; however, this has largely been replaced by the detection of minimal residual disease (MRD). Other than age and white blood cell count (WBC) at presentation, many clinical variables previously used for risk group allocation are no longer prognostic, as MRD and the presence of sentinel genetic lesions are more reliable at predicting outcome. Currently, a number of sentinel genetic lesions are used by most cooperative groups for risk stratification; however, in the near future patients will probably be risk‐stratified using genomic signatures and clustering algorithms, rather than individual genetic alterations. This review will describe the clinical, biological, and response‐based features known to predict relapse risk in childhood ALL, including those currently used and those likely to be used in the near future to risk‐stratify therapy.     

Glycophorin A mutations and risk of secondary leukaemia in patients treated for childhood acute lymphoblastic leukaemia

Survivors of childhood acute lymphoblastic leukaemia (ALL) have a higher than expected risk of developing secondary acute myeloid leukaemia (AML). The glycophorin A (GPA) mutation assay measures the frequency of variant NO and NN erythrocytes in MN heterozygotes. A raised variant frequency (Vf) has been shown in patients treated with chemotherapy known to be at risk of secondary leukaemia. ALL patients were investigated for increased Vf using the GPA assay. Vf's at diagnosis were not significantly different from controls (NO Vf P  = 0.193; NN Vf P  = 0.790). During treatment Vf's increased significantly (NO Vf P  = 0.001; NN Vf P  = 0.001). NO Vf returned to control values ( P  = 0.169) within 5 years from diagnosis but NN Vf remained significantly raised ( P  = 0.014). Three study patients developed secondary AML. At diagnosis of AML all three had significantly increased Vf. The first had a significantly raised Vf at routine follow-up 19 years following diagnosis of ALL then developed AML 3.5 years later. The second had a significantly raised NN Vf at diagnosis of ALL indicating possibly prior exposure to a mutagen or defective DNA repair involving erythroid stem cells. We conclude that a raised Vf detected by the GPA assay can act as a marker for the development of secondary induced leukaemia and can be used to screen individuals at a known high risk of this complication.     

Prognostic significance of cell surface markers in childhood acute lymphoblastic leukaemia

Examination of surface markers on leukaemic blasts from 51 children with ALL revealed that ALL is a heterogeneous disease. The majority (68 X) of patients with ALL lack surface markers (null leukaemia); 28% could be classed as T cell as they form rosettes with sheep RBC and 4% have been shown to possess surface immunoglobulins and hence are classed as B cells. The children with null cell leukaemia have a better prognosis than T and B cell types.     

Array comparative genome hybridization analysis of acute lymphoblastic leukaemia and acute megakaryoblastic leukaemia in patients with Down syndrome

Twenty-five cases of B-cell precursor acute lymphoblastic leukaemia (ALL) from Down syndrome (DS) patients were analyzed using array comparative genomic hybridization (aCGH) and compared with two other subgroups of non-DS patients with ALL; five cases with high-hyperdiploidy (HH) and nine cases with ETV6-RUNX1 positive clones. Seven cases of DS-acute megakaryoblastic leukaemia (AMKL) were also included, DS-ALL cases showed relatively stable karyotypes with cryptic losses and gains that most frequently involved chromosomes X, 1, 2, 9, 11, 16, and 17. The most consistent change involved a deletion in 2p, spanning region Chr2:88273220-91084234, which in some cases appeared to be homozygous. ALL from non-DS patients showed a similar overall karyotypic stability, although gains of chromosome 21 were infrequent in the ETV6-RUNX1 positive cases. The most consistent change in this group involved a 12p deletion, where Chr12:10383878-16017619 defined the common region of overlap. All HH-ALL karyotypes showed variable gains of chromosome 21. This overall analysis supports the suggestion that, although constitutional trisomy 21 predisposes to ALL/AMKL, the cytogenetic changes associated with DS-ALL in particular, are most similar to those found in non-DS ETV6-RUNX1 positive ALL. The HH-ALL group, however, undergoes distinct karyotypic evolution not dependent on chromosome translocation/deletion events.     

Quantitative expression of thrombopoietin receptor on leukaemia cells from patients with acute myeloid leukaemia and acute lymphoblastic leukaemia

Using a non-isotopic ligand binding assay, we quantitatively examined the amount of human thrombopoietin (TPO) receptor (TPO-R) on leukaemia cells from 128 patients with acute myeloid leukaemia (AML) or acute lymphoblastic leukaemia (ALL). The TPO-R was expressed in 53 (47%) of 114 AML cases, and an in vitro treatment with TPO led to proliferation (stimulation index >1.5) of leukaemia cells in 13 (20%) of 66 AML cases examined. The TPO levels had no relation to the FAB classification except for FAB-M7 AML. All five FAB-M7 cases expressed TPO-R, and one of three FAB-M7 examined showed in vitro proliferative response to TPO. Although there was no significant correlation ( r  = 0.3125) between the amount of TPO-R and the proliferative response, all of the AML cases which showed the in vitro response had TPO-R expression. There was no relationship between TPO-R amount and CD phenotypes, or the amount of granulocyte-colony stimulating factor (G-CSF) receptor. TPO-R was also expressed in two (14%) of 14 cases of ALL, and only these two cases had in vitro proliferative response to TPO. One had only lymphoid antigens, and the other had both lymphoid and myeloid antigens. Our results suggest that some leukaemia cells express functionally active TPO-R.     

Oligoclonality and new agent evaluation in acute lymphoblastic leukaemia

New agent development rests on the fundamental assumption that candidate agents or drug combinations that induce objective responses after relapse will prevent relapse, if applied prior to relapse. However, cumulative experience now includes at least 5 examples of interventions with post‐relapse objective response rates greater than 50% that failed to improve outcomes when applied prior to relapse. Emerging insights into oligoclonality provide some explanation. In acute lymphoblastic leukaemia, the predominant clones at relapse differ from the predominant clones at presentation. Arguably, the more highly proliferative clones that predominate at relapse differ in drug sensitivity from the less proliferative clones that escape primary therapy. Interventions effective against the predominant clones at relapse may have no effect on the antecedent escapee clones. Response is not sufficient in new agent development. Duration of response has attracted less attention because of variability in post‐remission therapy but some patient subsets have such a uniformly dismal outcome that details of post‐remission therapy may be irrelevant. Benchmarks are needed. Are recovering blasts members of the same clone or do they represent a new clone? When you eradicate the predominant clones you get a response. When you eradicate all clones, you get a cure.     

Advances in understanding the pathogenesis of CNS acute lymphoblastic leukaemia and potential for therapy

Central nervous system acute lymphoblastic leukaemia (CNS ‐ALL ) is a major clinical problem. CNS ‐directed ‘prophylactic’ chemo‐ or radio – therapy is associated with significant early and long‐term toxicity. Moreover, greater than a third of the relapses occur in the CNS . To design specific, more effective and less toxic therapy and for personalized precise adjustment of prophylactic therapy there is a need for better understanding of the biology of this disease. Specifically, the precise neurotropic mechanisms of ALL are currently unclear, as is the pathogenesis of CNS relapse. Here we review and contrast the recent findings with earlier studies of pathogenesis of CNS leukaemia. We also describe the challenges in research of this devastating complication of ALL .     

Increased regulatory T cells in acute lymphoblastic leukaemia patients

Introduction: Regulation in adaptive immune response balances a fine line that prevents instigation of self-damage or fall into unresponsiveness permitting abnormal cell growth. Mechanisms that keep this balance in check include regulatory T cells (Tregs). Tregs consist of a small but heterogeneous population, which may be identified by the phenotype, CD3+CD4+CD25+CD127?. The role of Tregs in pathogenesis of cancers is thus far supported by evidence of increased Tregs in various cancers and may contribute to poorer prognosis. Tregs may also be important in acute leukaemias.

Objective: A review of the literature on Tregs in acute leukaemias was conducted and Tregs were determined in B-cell acute lymphoblastic leukaemias (ALLs).

Results: Studies on Tregs in B-cell ALL are few and controversial. We observed a significantly increased percentage of Tregs (mean±SD, 9.72?±?3.79% vs. 7.05?±?1.74%; P?=?0.047) in the bone marrow/peripheral blood of ALL (n?=?17) compared to peripheral blood of normal controls (n?=?35). A positive trend between Tregs and age (R?=?0.474, P?=?0.055, n?=?17) implicates this factor of poor prognosis in B-cell ALL.

Discussion: Tregs in cancer are particularly significant in immunotherapy. The manipulation of the immune system to treat cancer has for a long time ignored regulatory mechanisms inducible or in place. In lymphoma studies, tumour-specific mechanisms that are unlike conventional methods in the induction of Tregs have been hypothesized. In addition, tumour-infiltrating Tregs may present different profiles from peripheral blood pictures. Tregs will continue to be dissected to reveal its mysteries and their impact on clinical significance.     

Towards targeted therapy for infant acute lymphoblastic leukaemia

Despite the greatly improved treatment regimes for childhood acute lymphoblastic leukaemia (ALL) in general, resulting in long-term survival in approximately 80% of cases, current therapies still fail in >50% of ALL cases diagnosed within the first year of life (i.e. in infants). Therefore, more adequate treatment strategies are urgently needed to also improve the prognosis for these very young patients with ALL. Here we review the current acquaintance with the biology of infant ALL and describe how this knowledge may lead to innovative therapeutic approaches.