Early postinduction intensification therapy is essential in childhood acute lymphoblastic leukemia

Postinduction intensification therapy (PII) has been key to success in the treatment of many types of childhood cancer and has led to an increase in cure rates during the past 3 decades. This Practice Point commentary discusses the recent findings of the Children's Cancer Group CCG-1961 study, which enrolled 2,078 children and adolescents with acute lymphoblastic leukemia. Patients with rapid marrow response to induction therapy were randomly allocated in a 2 x 2 factorial trial to receive either longer or increased intensity PII. A clear advantage--9% improved event-free survival and 6% improved overall survival at 5 years--was shown for more-intensive but not for longer PII; however, a high incidence of osteonecrosis and an increased rate of infections were observed in rapid early responders. This commentary emphasizes the need to balance the beneficial effects of PII in terms of disease control against the possibility of potentially debilitating late adverse sequelae.     

Outcome following late marrow relapse in childhood acute lymphoblastic leukemia

Thirty-four children with acute lymphoblastic leukemia, who developed bone marrow relapse after treatment was electively stopped, received reinduction, consolidation, continuing therapy, and intrathecal (IT) methotrexate (MTX). Sixteen children who relapsed within six months of stopping treatment had a median second-remission duration of 26 weeks; all next relapses occurred in the bone marrow. In 18 children who relapsed later, the median duration of second remission was in excess of two years, but after a minimum of four years' follow-up, 16 patients have so far relapsed again (six in the CNS). CNS relapse occurred as a next event in four of 17 children who received five IT MTX injections only and in two of 14 children who received additional regular IT MTX. Although children with late marrow relapses may achieve long second remissions, their long-term out-look is poor, and regular IT MTX does not afford adequate CNS prophylaxis. It remains to be seen whether more intensive chemotherapy, including high-dose chemoradiotherapy and bone marrow transplantation, will improve the prognosis in this group of patients.     

Early resistance to therapy during induction in childhood acute lymphoblastic leukemia

Many patients with acute lymphoblastic leukemia (ALL) are not cured by current therapy because of the development of drug resistance. It is not clear when resistance develops during the growth of the leukemic clone and whether resistant cells are already present at diagnosis or develop later during treatment. Twenty-two uniformly treated children with ALL were studied throughout induction treatment. The size of the leukemic clone in blood and marrow was estimated by limiting dilution PCR analysis, using the rearranged immunoglobulin heavy chain gene as a molecular marker. The decline in the number of leukemic cells was biphasic in virtually all patients. For both marrow and blood, the logarithmic mean of the number of leukemic cells fell by approximately four orders of magnitude during the first 2 weeks, one order of magnitude during the third week, and not at all during the last two weeks of induction treatment. For marrow, the median of the fraction of leukemic cells in each patient that survived per week of treatment was 0.008 for the first 2 weeks, 0.12 for the third week, and 1.4 for the last 2 weeks; for blood, the corresponding figures were 0.003, 0.14, and 0.69, respectively. In individual patients, the results for marrow and blood showed good correlation. The biphasic decline of leukemic cell number suggests that most leukemic cells were sensitive to treatment and were rapidly killed, leaving behind a minor but substantial population of drug-resistant cells. The most likely explanation for this phenomenon is that these resistant cells were already present at diagnosis, their resistance having originated from genetic or epigenetic mutations during prior growth of the leukemic clone.     

Aven overexpression: association with poor prognosis in childhood acute lymphoblastic leukemia

Aven expression has recently been identified as an anti-apoptotic protein. In this study, Aven expression in 91 children with acute lymphoblastic leukemia (ALL) was investigated for possible correlation with clinical features at diagnosis and treatment outcome. Aven expression was found to be higher in patients >or=10 years old or <1 year (P=0.003), and in patients with unfavorable cytogenetic abnormalities (P<0.001). Aven expression was also significantly higher in relapsed patients in the standard-risk group. Aven overexpression was an independent poor prognostic factor. These findings demonstrate that Aven expression can predict prognosis in childhood ALL.     

Anthracycline dose intensification in adult acute lymphoblastic leukemia

BACKGROUND:

In previous studies of frontline therapy for adult acute lymphoblastic leukemia (ALL), early treatment with higher doses of anthracyclines has been reported to improve outcome. The current study was conducted to evaluate whether addition of anthracycline‐based consolidation chemotherapy (Course 2) with liposomal daunorubicin (150 mg/m² intravenously [IV] on Days 1 and 2) and cytarabine (1.5 g/m² IV on Days 1 and 2) to the standard hyper‐CVAD regimen (fractionated cyclophosphamide, vincristine, doxorubicin, and dexamethasone alternating with high dose methotrexate and cytarabine) would improve outcome.

METHODS:

Sixty‐eight consecutive adults with de novo ALL or lymphoblastic lymphoma were treated with this modified hyper‐CVAD regimen inclusive of rituximab for CD20 expression ≥20%.

RESULTS:

Sixty‐three (93%) patients achieved complete response (CR). With a median follow‐up of 90 months, the 5‐year CR duration (CRD) and overall survival (OS) rates were 46% and 44%, respectively. Compared with 208 patients treated with standard hyper‐CVAD (rates of 45% and 47%, respectively; P = not significant), outcome with the modified hyper‐CVAD regimen was not improved overall. Outcome was improved by the addition of rituximab for the CD20‐positive subset (rates of CRD and OS of 50% and 53%, respectively), whereas anthracycline intensification worsened outcome for the CD20‐negative subset (rates of CRD and OS of 41% and 35%, respectively; P = .01) compared with standard hyper‐CVAD. A high mortality rate related to infections in CR was noted among patients aged 60 years or older.

CONCLUSIONS:

In the context of the hyper‐CVAD regimen, early anthracycline intensification did not improve outcome for adults with de novo ALL or lymphoblastic lymphoma. Cancer 2010. © 2010 American Cancer Society.     

Genomic analysis drives tailored therapy in poor risk childhood leukemia

VEGF-C and VEGF-D have been implicated in lymphatic metastasis, mainly as inducers of new intra/peritumoral capillary lymphatics. In this issue of Cancer Cell, Karnezis and colleagues challenge this notion and demonstrate that tumor-derived VEGF-D promotes metastasis by causing prostaglandin-dependent dilation of collecting lymphatics outside of the tumor mass.     

Genetic susceptibility to childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common pediatric cancer. The origin of this disease can be explained by a combination of genetic susceptibility factors and environmental exposures. For the purpose of our study it can be considered as a complex disease, caused by the "carcinogenic" effect of the environment modified by a series of genes. In population, these genes tend to occur in allelic forms representing functional polymorphisms thus explaining inter-individual variability in cancer susceptibility. The latter can be evaluated more realistically in childhood ALL than in sporadic cancers of the adult because of its relatively short latency period. We asked therefore, the question about the role of genes controlling the efficiency of xenobiotics metabolism in childhood leukemogenesis. Xenobiotics (drugs and carcinogens) are excreted from the body after metabolic conversion by enzymes mediating oxidation activation (Phase I) and conjugation detoxificaton (Phase II). Functional variants of these enzymes, resulting from known DNA polymorphisms in the corresponding genes, were shown to influence the risk to a variety of solid tumours in adults. A case-control study on ALL patients and healthy controls in a French-Canadian population was carried out by examining the loci of Phase I, CYP1A1 and CYP2D6, as well as Phase II enzymes, GSTM1, GSTT1, NAT1 and NAT2. The NAT2 slow-acetylator, CYP1A1*2A and GSTM1 null genotypes were shown to be significant risk determinants of ALL (OR=1.6, 1.8 and 1.8, respectively), whereas, polymorphisms in CYP2D6 and GSTT1 genes did not seem to play an important role in the aetiology of ALL. Interestingly, the risk associated with NAT2 slow-acetylators was most apparent among males homozygous for NAT1*4 (OR=3.3) whereas girls carrying the CYP1A1*4 allele were significantly underrepresented in the patient group (OR=0.2). These findings point to a gender-specific effect of DNA variants which, at least in part, may explain why ALL is more prevalent among boys. To assess gene-gene interactions, NAT2 slow-acetylators were considered together with GSTM1 null genotypes and CYP1A1*2A alleles. The combined presence of two risk-elevating genotypes appeared to confer an increased risk of ALL among the carriers (OR=2.6). This risk was increased further (OR=3.3) when all three genotypes occurred in the same individuals indicating that the combination of susceptibility variants is more predictive of risk then either of them independently. The association of leukemogenesis in children with metabolising gene variants suggests causal relation to environmental exposures.     

Acute lymphoblastic leukemia of childhood

Over the last 20 years, the rate of long-term disease-free survival of childhood acute lymphoblastic leukemia increased from less than 1 to 60 per cent. Strategies for disease control include (1) intensive multiagent induction to rapidly decrease the tumor burden and minimize the chance of emergence of a resistant population of cells, (2) restoration of normal hematopoiesis as soon as possible to reduce the period of pancytopenia, (3) meticulous supportive care, (4) prevention of sanctuary disease, and (5) therapy tailored to the potential risk of relapse as predicted by the prognostic factors of the patient. Further progress must be made in identifying prognostic factors, preventing and treating relapse, finding novel modalities of therapy, and delineating and minimizing long-term side effects.     

Prognostic subgrouping and early or late intensification of the treatment of childhood acute lymphocytic leukemia

Current therapy for childhood ALL is effective and certainly much better than what was available 10 years ago. According to our protocol 721, 745, and 765 studies, between 40% and 60% of children with ALL are now on long-term survival, even after discontinuation of the therapy for several years. However, results are not nearly as good in patients who have identifiable poor risk features. A review of 162 patients with ALL was undertaken to determine the important factors, other than therapy, influencing survival. Childhood ALL can be divided into two groups according to major prognostic factors such as age and initial leukocyte counts; Group I -standard risk group and Group II -high risk group. To minimize side effects while trying to improve further efficacy of therapy and to prevent late relapse, our new protocol 811 has been initiated for standard risk patients of ALL. The more aggressive use of current agents such as methotrexate and adriamycin to prevent early relapse has been applied for high risk patients of ALL. The preliminary results of protocol 811 showed that early intensification with high-dose methotrexate and adriamycin seemed to prolong the remission duration of high risk ALL, but further long follow-up study is needed. With considerable progress being made toward the cure of childhood leukemias, the issue of late effects assumes increasing importance. The next generation of treatment studies, in addition to further attempts at improving the proportion of survivors, will need to develop strategies aimed at clearly defining and minimizing these late sequelae.     

Reinduction therapy for advanced or refractory acute lymphoblastic leukemia of childhood

Thirty-four children after multiple relapse or with refractory acute lymphoblastic leukemia were treated with two novel combinations of high-dose cytosine arabinoside, methotrexate, asparaginase, vincristine, and prednisone. The first combination was given to 19 patients. Oncolytic response and marrow hypoplasia was achieved in all. There were four early infectious deaths. Thirteen of the remaining 15 (87%) in whom the response to therapy could be evaluated achieved complete remission. Two achieved good partial remissions. The median duration of complete remission and survival on study was 8 and 10 months, respectively. The four proven and three suspected fungal infections seen in the initial 19 patients was the major toxicity observed. The therapy was modified in the last 15 patients to retain efficacy while reducing the period of neutropenia from a median of 28 to 22 days. No deep-seated fungal infections were seen in these patients. Twelve (80%) achieved a complete remission. Three had an oncolytic response without achieving remission. Eighty-three percent of the 30 evaluable patients, or 74% of all patients entered on study, achieved remission. It is anticipated that the therapy described here will not only achieve another remission in the majority of patients with advanced ALL but that the patients will be able to proceed to alternate therapies with potentially more durable benefit.     

Glucocorticoid receptor in childhood acute lymphoblastic leukemia

Glucocorticoid(GC)hasbeenusedinthetreatmentofchildhoodacutelymphoblasticleukenda(ALL)formanyyears.IthasprovedthattheeffectofGCismediatedthroughaglucocortic0idreceptor(GCR)ofthetargetcell.[1]Therefore,manyexpertshaveconcentratdtheirattentiononGCR,butthereisnoreportonthestudyofGCRinchildho0dALLinChina.InununologicalclassificationofALLmaydifferentiatethecelloriginandclustersofdifferentiation(CD)inleukendacell.Itisoneoftheimportantindicatorstoguidecombinationchemotherapyandt0makeapr0gnos…     

Enhanced expression of p16ink4a is associated with a poor prognosis in childhood acute lymphoblastic leukemia.

The tumor suppressor gene p16ink4a is homozygously deleted in numerous T as well as in some B lineage acute lymphoblastic leukemia (ALL). We therefore analyzed the clinical and biological implications of this feature by studying p16ink4a expression in 58 cases of childhood ALL. mRNA and protein were significantly correlated and both appeared more highly expressed in B than in T lineage ALLs: 13 out of the 15 T cell ALLs did not show any p16ink4a expression. The main result of this study is the strong prognostic value of p16ink4a expression. When stratifying the patients in three groups according to p16ink4a expression, we observed in univariate analysis: (1) the shortest disease-free survival for patients presenting a high p16ink4a level; (2) contrasting with the good prognosis in the group of patients expressing p16ink4a at low level; (3) while cases without any expression of the inhibitor were associated with a medium course of the disease (P=0.0165). This prognostic value was confirmed by the multivariate analysis showing therapeutic regimen and p16ink4a protein expression as the only variables retained in the model. A specific metabolic profile related to cellular survival and proliferation was observed in each of the three p16ink4a expression groups. Among the cell cycle-related proteins we analyzed, only p21waf1 bcl-2 and CDK4 were significantly and positively correlated to p16ink4a. Furthermore, CDK6 was also strongly expressed in the group of cases with high p16ink4a level. An enhancement of p16ink4a, p21waf1 and bcl-2 was previously described in prolonged cellular survival, while aging cells showed a decrease in CDK4 expression. The concomitant high expression of the oncogenic protein CDK4 (and of CDK6), we observed, may amplify the leukemic advantage of prolonged lifespan blast cells by favoring cell progression through G1 phase. These data suggest that at least two mechanisms may be associated in the oncogenesis of very aggressive ALLs, ie deregulation of cell multiplication and prolonged blast lifespan.     

Genetic susceptibility in childhood acute lymphoblastic leukemia

Acute lymphoblastic leukemia (ALL) is the most common childhood malignancy and a leading cause of death due to disease in children. The genetic basis of ALL susceptibility has been supported by its association with certain congenital disorders and, more recently, by several genome-wide association studies (GWAS). These GWAS identified common variants in ARID5B, IKZF1, CEBPE, CDKN2A, PIP4K2A, LHPP and ELK3 influencing ALL risk. However, the risk variants of these SNPs were not validated in all populations, suggesting that some of the loci could be population specific. On the other hand, the currently identified risk SNPs in these genes only account for 19% of the additive heritable risk. This estimation indicates that additional susceptibility variants could be discovered. In this review, we will provide an overview of the most important findings carried out in genetic susceptibility of childhood ALL in all GWAS and subsequent studies and we will also point to future directions that could be explored in the near future.     

Immunologic markers in childhood acute lymphoblastic leukemia

This article details the immunologic diversity of acute lymphoblastic leukemia in children. A historical review of developments in immunophenotyping is followed by a discussion of how major subgroups of leukemia are best defined today. The relationship of immunologic subtypes to stages of normal lymphoid development is explored, and the clinical impact of immunophenotyping is discussed.     

Early response to induction therapy as a predictor of disease-free survival and late recurrence of childhood acute lymphoblastic leukemia: a report from the Childrens Cancer Study Group

The Childrens Cancer Study Group (CCSG) CCG-160 protocol series was designed to evaluate prognostic factors in acute lymphoblastic leukemia (ALL). Patients were assigned to one of three prognostic groups based upon initial WBC count and age. To determine the optimal duration of therapy, CCG-160 patients completing 2 years of treatment in continuous remission were randomized ("late randomization") to discontinue therapy or receive another year of maintenance therapy. The prognostic significance of early response to induction therapy, as measured by the percentage of lymphoblasts in the day-14 bone marrow (d14 BM) aspirate, was evaluated in 2,516 children. For 1,490 patients with complete data, the status of the d 14 BM was a highly significant predictor of disease-free survival (DFS) by univariate and multivariate analysis (P less than .0001). The observed/expected (O/E) failure rate in patients with d14 M1 (less than 5% blasts), M2 (4% to 25% blasts), or M3 (greater than 25% blasts) BM rating who were subsequently M1 on day 28 or day 42, was .87, 1.59, and 2.30, respectively (P less than .0001). Patients with M2 or M3 d14 BM were more likely to have L2 ALL (modified French-American-British [FAB] morphologic classification), P less than .001. The significance of the d14 BM rating persisted after correction was made for WBC count and clinical prognostic groups using current CCSG criteria, except in infants less than 12 months of age. The d14 BM was also the most significant predictor of DFS in 975 patients after late randomization at 2 years following diagnosis. The O/E failure rate in patients with d14 M1, M2, or M3 BM was .88, 1.78, and 2.02, respectively (P = .0002, trend). Other significant predictors of late relapse were prognostic groups (P = .0003, trend) and initial WBC count (P = .004, trend). Predictive for both early and late relapse of ALL, early response should be monitored closely and alternative treatment regimens should be considered for slow responders.     

Induction failure in acute lymphoblastic leukemia of childhood

BACKGROUND: Although it is widely accepted that failure to achieve complete remission (CR) portends a poor prognosis in childhood acute lymphoblastic leukemia (ALL), there is variability in the precise definition of induction failure and, to the authors' knowledge, few published data exist regarding the outcome of patients who are slow to achieve CR. METHODS: Between 1987-1995, 774 children with ALL were treated on 2 consecutive protocols and were evaluable to assess the time required to attain CR. The authors compared presenting characteristics and outcomes of patients based on their remission status after 1 month of induction chemotherapy: CR (n = 656), protracted hypoplasia (low peripheral blood counts and/or hypocellular marrow) (n = 95), and persistent leukemia (M2 or M3 bone marrow and/or evidence of extramedullary leukemia) (n = 23). The median follow-up was 5.2 years. RESULTS: Presenting features that predicted persistent leukemia included a leukocyte count > 100,000/mm3 and T-cell phenotype. Approximately 91% of patients with persistent leukemia and 100% with protracted hypoplasia eventually achieved CR. The 5-year event free survival (EFS) (95% confidence intervals [95% CI] in parentheses) for patients with persistent leukemia after 1 month was 16% (95% CI, 0%, 31%), which was significantly worse (P < 0.001) than that for those who achieved CR within 1 month (5-year EFS, 82%; 95% CI, 79%, 86%) and that for those with protracted hypoplasia (5-year EFS, 79%; 95% CI, 70%, 87%). For patients with persistent leukemia, there was no significant difference in survival based on bone marrow status (M2 or M3) after 1 month or on the number of induction cycles received before achieving CR. CONCLUSIONS: Patients with persistent leukemia at the end of 1 month of therapy have a dismal prognosis, regardless of when they subsequently achieve CR. More intensive and/or novel therapies should be considered for this subset of patients.     

Spectral characteristics of acute lymphoblastic leukemia in childhood

Although the differentiation and classification of acute leukemia are based upon cytochemical features as well as immunologic, cytogenetic, and molecular characteristics, in many cases the morphological distinction of normal lymphocytes from lymphoblasts of acute lymphoblastic leukemia (ALL) is difficult using light microscopy. In this study the distinction between normal lymphocytes and lymphoblasts of childhood ALL is proposed using their spectral characteristics. The method has been based upon the analysis and classification of optical absorption characteristics of the bone marrow cells. Spectral microscopy system is capable of capturing a great number of narrow-band images, in the wide spectral range of the optical spectrum. The analysis showed statistically significant difference (P < 0.0001) between normal lymphocytes and lymphoblasts as far as it concerns the detection, identification and mapping of their spectral absorption characteristics. Our results suggest the potential of spectral imaging as a new method for the distinction of lymphocytes from lymphoblasts in cases that with the light microscope, the morphologic differences are not visible in the bone marrow smears at diagnosis or the follow up of the children with ALL.     

Outcomes of growth hormone replacement therapy in survivors of childhood acute lymphoblastic leukemia.

PURPOSE: Little is known about the long-term efficacy or adverse effects of growth hormone (GH) replacement therapy in survivors of childhood acute lymphoblastic leukemia (ALL) who have GH deficiency. We investigated the adult height of patients who had received GH and estimated their risk of leukemia relapse or development of a second malignancy. PATIENTS AND METHODS: Of 910 patients treated for ALL at a single institution, 47 had received GH replacement therapy. The linear growth of these 47 patients was retrospectively evaluated. Their risk of leukemia relapse or second malignancy was compared with that of survivors who did not undergo GH therapy. RESULTS: The median height SD score at the start of GH therapy had decreased by 1.0 since the time of diagnosis of ALL. After a median duration of 4.5 years of GH therapy, adult height SD scores improved and approached height SD scores at the time of diagnosis of ALL. The median adult height for male patients was 173.2 cm (range, 157 to 191.9 cm), and for female patients, it was 158.1 cm (range, 141 to 168 cm). None of the patients developed adverse effects requiring discontinuation of GH treatment. At the 7-year and 11-year landmarks in continuous hematologic remission, there was no statistical evidence that GH therapy was associated with leukemia relapse or development of a second malignancy. CONCLUSION: This study suggests that GH replacement therapy is safe and efficacious for the correction of GH deficiency in survivors of childhood ALL.     

Late recurrence of childhood acute lymphoblastic leukemia

Late relapse of childhood lymphoblastic leukemia 10 years after the end of treatment is rare. A young woman whose acute lymphoblastic leukemia recurred 11 years after the end of treatment for acute lymphoblastic leukemia is described, and the literature on late relapse of childhood acute lymphoblastic leukemia is reviewed.