Acute Leukemia in Adolescents and Young Adults

Epidemiological characteristics and influencing factors of acute leukemia in children and adolescents and adults: a large population-based study

OBJECTIVE

To assess the epidemiological characteristics and prognostic factors of acute leukemia (AL) in children and adolescents, and make comparisons between pediatric and adult patients.

METHODS

This retrospective cohort study enrolled AL patients from the Surveillance, Epidemiology, and End Results (SEER) 1975-2016. OS in children and adolescents and adults with AL was compared and analyzed separately by age and AL subtype.

RESULTS

Totally 61,694 AL patients were identified, with 45,411 (73.6%) adults and 16,283 (26.4%) children and adolescents. From 2000 to 2016, the incidence rates of AL [annual percent changes (APC) = 1.2, 95%CI = 0.9-1.6, P < 0.05] and acute lymphoblastic leukemia (ALL) (APC = 1.5, 95%CI = 1.1-1.8, P < 0.05) in children and adolescents were significantly increasing. For adults, AL (APC = 0.9, 95%CI = 0.3-1.5, P < 0.05), ALL (APC = 2.5, 95%CI = 2.0-3.1, P < 0.05) and acute myeloid leukemia (AML) (APC = 0.9, 95%CI = 0.4-1.5, P < 0.05) had significantly elevated incidence rates. Overall survival (OS) in children and adolescents with AL was significantly higher than that in adults with AL (log-rank P < 0.0001). OS in children and adolescents and adults with ALL, AML and AUL decreased with age (all log-rank P < 0.0001). Older age, male sex and black race were risk factors for the survival of children and adolescents and adults with ALL, AML and AUL.

CONCLUSION

From 2000 to 2016, the incidence rates of AL in children and adolescents and adults were increasing. Children and adolescents with AL had significantly better OS than adults with AL, and OS declined with age in both children and adolescents and adults with ALL, AML and AUL.

Acute Lymphoblastic Leukemia Immunotherapy Treatment: Now, Next, and Beyond

Acute lymphoblastic leukemia (ALL) is a blood cancer that primarily affects children but also adults. It is due to the malignant proliferation of lymphoid precursor cells that invade the bone marrow and can spread to extramedullary sites. ALL is divided into B cell (85%) and T cell lineages (10 to 15%); rare cases are associated with the natural killer (NK) cell lineage (<1%). To date, the survival rate in children with ALL is excellent while in adults continues to be poor. Despite the therapeutic progress, there are subsets of patients that still have high relapse rates after chemotherapy or hematopoietic stem cell transplantation (HSCT) and an unsatisfactory cure rate. Hence, the identification of more effective and safer therapy choices represents a primary issue. In this review, we will discuss novel therapeutic options including bispecific antibodies, antibody-drug conjugates, chimeric antigen receptor (CAR)-based therapies, and other promising treatments for both pediatric and adult patients.

Recent findings regarding the synergistic effects of emodin and its analogs with other bioactive compounds: Insights into new mechanisms

CONTEXT

Emodin is a natural bioactive ingredient mainly extracted from traditional Chinese herbs. Increasing lines of evidence suggest that emodin and its analogs exert notable synergistic pharmacological effects with other bioactive compounds.

OBJECTIVE

This review provides an overview of the pharmacological activity of emodin and its analogs in combination with other physiologically active substances, describes the related molecular mechanisms, and discusses future prospects in this field.

METHODS

Information from multiple scientific databases, such as PubMed, the China Knowledge Resource Integrated Database from the China National Knowledge Infrastructure (CNKI), the Web of Science, Google Scholar, and Baidu Scholar, was collected between January 2006 and August 2022. The subject terms used in the literature search were emodin, pharmaceutical activities, analogs, aloe emodin, rhein, and synergistic effects.

RESULTS

The comprehensive literature analysis suggested that combinations of emodin or its analogs with other bioactive compounds exert notable synergistic anticancer, anti-inflammatory, and antimicrobial effects and that such combinations improve glucose and lipid metabolism and central nervous system diseases.

DISCUSSION AND CONCLUSIONS

Further assessments of the dose-effect relationship and the differences in the efficacy of emodin or its analogs with other bioactive compounds among various modes of administration are needed, and a drug safety evaluation of these combinations needs to be carefully performed. Future studies should also focus on determining the optimal drug combinations for specific diseases.

Why Do Children with Acute Lymphoblastic Leukemia Fare Better Than Adults?

It is a new and exciting time for acute lymphoblastic leukemia (ALL). While nearly 50 years ago, only one in nine children with ALL survived with chemotherapy, nowadays nearly 90% of children have a chance of long-term survival. Adults with ALL, as well as the special category of adolescents and young adult (AYA) patients, are catching up with the new developments seen in children, but still their prognosis is much worse. A plethora of factors are regarded as responsible for the differences in treatment response, such as age, ethnicity, disease biology, treatment regimens and toxicities, drug tolerance and resistance, minimal residual disease evaluation, hematopoietic stem cell transplantation timing and socio-economic factors. Taking these factors into account, bringing pediatric-like protocols to adult patient management and incorporating new agents into frontline treatment could be the key to improve the survival rates in adults and AYA.

Far from Health: The Bone Marrow Microenvironment in AML, A Leukemia Supportive Shelter

Acute myeloid leukemia (AML) is the second most common leukemia among children. Although significant progress in AML therapy has been achieved, treatment failure is still associated with poor prognosis, emphasizing the need for novel, innovative therapeutic approaches. To address this major obstacle, extensive knowledge about leukemogenesis and the complex interplay between leukemic cells and their microenvironment is required. The tremendous role of this bone marrow microenvironment in providing a supportive and protective shelter for leukemic cells, leading to disease development, progression, and relapse, has been emphasized by recent research. It has been revealed that the interplay between leukemic cells and surrounding cellular as well as non-cellular components is critical in the process of leukemogenesis. In this review, we provide a comprehensive overview of recently gained knowledge about the importance of the microenvironment in AML whilst focusing on promising future therapeutic targets. In this context, we describe ongoing clinical trials and future challenges for the development of targeted therapies for AML.

Increased Toxicity Among Adolescents and Young Adults Compared with Children Hospitalized with Acute Lymphoblastic Leukemia at Children's Hospitals in the United States

Purpose: Adolescent and young adult (AYA) patients (15-39 years old) with acute lymphoblastic leukemia (ALL) have less favorable outcomes and higher treatment-related mortality as compared with older children with ALL. Minimal data exist regarding how well AYA patients tolerate the intensity of chemotherapy at doses and regimens designed for children, and the toxicities suffered by this population at children's hospitals have not been thoroughly characterized. Methods: Pediatric Health Information Systems database was queried to analyze health care outcomes in pediatric (ages 10-14) and AYA patients (ages 15-39) with ALL hospitalized between January 1999 and December 2014. We extracted relevant ICD-9 data for each patient related to grades 3 or 4 toxicities as outlined by the NCI. Results: A total of 5345 hospital admissions met inclusion criteria, representing 4046 unique patients. Of these admissions, 2195 (41.1%) were in the AYA age group, and the remainder were in the 10-14-year-old group. AYA patients had a significantly higher incidence of intensive care unit stay but no difference in median hospital stay nor mortality. AYA patients had increased toxicities in almost every organ system as compared with older children. Conclusions: In this large multicenter US database study, we found an overall increased number of toxicities among AYA patients with ALL in children's hospitals. Compared with children between the ages of 10 and 15, AYA patients developed disproportionately higher toxicities from drugs commonly used in pediatric protocols for ALL. Prospective studies are needed to assess whether dose modifications for certain chemotherapeutics may improve the toxicity profile and health care burden of AYA patients with ALL treated in children's hospitals.

Adolescent and Young Adult Cancer Biology

Adolescent and young adult (AYA) patients with cancer have not attained the same improvements in overall survival as either younger children or older adults. One possible reason for this disparity may be that the AYA cancers exhibit unique biologic characteristics, resulting in differences in clinical and treatment resistance behaviors. Our current understanding of the unique biological/genomic characteristics of AYA cancers is limited. However, there has been some progress that has provided clues about the biology of AYA cancers. We here review the latest findings in the area of AYA cancer biology and discuss what is required to advance the field for the more effective treatment of this patient population.

The Mechanism of Bufalin-Induced Apoptosis of K562/A02

Background

In clinical practice, many patients become multidrug resistant during chemotherapy, resulting in reduced or no healing effect. Therefore, the present study focused on bufalin, which is extracted from a traditional Chinese medicine named Chan Su (Venenum bufonis). We assessed the effect of bufalin in reversing K562/A02 cell drug resistance and inducing apoptosis, and explored the possible mechanism by which bufalin induces K562/A02 cell apoptosis.

Material/Methods

We used flow cytometry to evaluate intracellular ADM concentration, and RT-PCR and Western blot analysis were used to assess the effect of nuclear factor erythroid-2-related factor 2 (Nrf2) bufalin-related resistance gene expression. We used MTT and flow cytometry to detect apoptosis, and RT-PCR and Western blot were used to detect endoplasmic reticulum stress and apoptosis gene action.

Results

We found that bufalin can increase the concentration of Adriamycin (ADM) in K562/A02 cells by inhibiting the expression of Nrf2 and related drug resistance factors. The results showed that bufalin induced apoptosis of K562/A02 cells by the IRE1α/TRAF2/JNK/caspase-12 pathway.

Conclusions

These results suggest bufalin can reverse drug resistance in K562/A02 cells and that it induces apoptosis of K562/A02 cells by the IRE1α/TRAF2/JNK/caspase-12 pathway.

Age-related differences in the bone marrow stem cell niche generate specialized microenvironments for the distinct regulation of normal hematopoietic and leukemia stem cells

The bone marrow (BM) microenvironment serves as a stem cell niche regulating the in vivo cell fate of normal hematopoietic stem cells (HSC) as well as leukemia stem cells (LSCs). Accumulating studies have indicated that the regeneration of normal HSCs and the process of leukemogenesis change with advancing age. However, the role of microenvironmental factors in these age-related effects are unclear. Here, we compared the stem cell niche in neonatal and adult BM to investigate potential differences in their microenvironmental regulation of both normal and leukemic stem cells. We found that the mesenchymal niche in neonatal BM, compared to adult BM, was characterized by a higher frequency of primitive subsets of mesenchymal stroma expressing both platelet-derived growth factor receptor and Sca-1, and higher expression levels of the niche cross-talk molecules, Jagged-1 and CXCL-12. Accordingly, normal HSCs transplanted into neonatal mice exhibited higher levels of regeneration in BM, with no difference in homing efficiency or splenic engraftment compared to adult BM. In contrast, in vivo self-renewal of LSCs was higher in adult BM than in neonatal BM, with increased frequencies of leukemia-initiating cells as well as higher lympho-myeloid differentiation potential towards biphenotypic leukemic cells. These differences in LSC self-renewal capacity between neonates and adults was abrogated by switching of recipients, confirming their microenvironmental origin. Our study provides insight into the differences in leukemic diseases observed in childhood and adults, and is important for interpretation of many transplantation studies involving neonatal animal models.

Treatment strategies for adolescent and young adult patients with acute myeloid leukemia

Adolescents and young adults (AYAs) form a unique group of patients with newly diagnosed acute myeloid leukemia (AML). They differ in terms of disease biology, psychosocial challenges, survival, and in other important respects from children as well as from middle-aged and older adults. AYAs may be treated using pediatric protocols developed in trials composed primarily of younger patients, or using adult protocols developed in trials composed primarily of older patients. After reviewing the distinguishing characteristics of AYAs with AML, we compare and contrast the chemotherapy approaches and argue that neither the pediatric nor adult approaches may be ideally suited for AYAs and the development of AYA-specific approaches merits further consideration. We finish by putting forth ideas for future research to optimize chemotherapy treatment of AYAs with AML.

FDA Approval Summary: Mylotarg for Treatment of Patients with Relapsed or Refractory CD33-Positive Acute Myeloid Leukemia

On September 2, 2017, the U.S. Food and Drug Administration approved gemtuzumab ozogamicin (GO; Mylotarg; Pfizer, New York City, NY) for treatment of relapsed or refractory (R/R) CD33-positive acute myeloid leukemia (AML) in patients 2 years of age and older. GO is a CD33-directed antibody drug conjugate linked to the cytotoxic antibiotic calicheamicin. It originally received accelerated approval for treatment of older patients with relapsed CD33-positive AML in 2000, but it was withdrawn from the market in 2010 when the confirmatory trial failed to demonstrate clinical benefit among safety concerns, such as a higher rate of induction fatalities on the GO combination arm compared with chemotherapy alone. In addition, GO was associated with hepatic veno-occlusive disease (VOD), which has substantial morbidity and mortality. Pharmacokinetic analyses suggested a lower maximum concentration of GO would result in less VOD without affecting target saturation or efficacy. A meta-analysis across dose schedules of GO in patients with R/R AML showed that a lower-dose "fractionated" schedule of 3 mg/m² days 1, 4, and 7 was associated with less early mortality, hemorrhage, and VOD, without an apparent decrease in complete remission (CR) rate. MyloFrance 1 was a single-arm study evaluating response rates in patients with relapsed CD33-positive AML treated with the lower-dose fractionated GO regimen. The CR rate was 26% (95% confidence interval 16%-40%). Common adverse reactions were fever, infections, nausea, vomiting, constipation, bleeding, increased liver enzymes, and mucositis. There were no cases of VOD. These results supported the approval of GO as monotherapy for R/R CD33-positive AML using the lower-dose fractionated regimen.

IMPLICATIONS FOR PRACTICE

Gemtuzumab ozogamicin (GO) 3 mg/m² days 1, 4, and 7 is an active regimen for induction of remission when used to treat patients with relapsed or refractory CD33-positive acute myeloid leukemia without curative intent. The risks of hepatic veno-occlusive disease and early mortality with this regimen appear to be lower than reported previously for GO 9 mg/m² days 1 and 15. The data were not sufficient to enable conclusions about the safety of GO in children younger than 2 years of age.

Voriconazole plus caspofungin for treatment of invasive fungal infection in children with acute leukemia

Background

Invasive fungal infections (IFIs) are a life-threatening problem in immunocompromised patients. Despite timely diagnosis and appropriate antifungal therapy, clinical outcomes of IFIs remain unsatisfactory, necessitating treatment with a combination of antifungal agents. Therefore, childhood leukemic patients treated with voriconazole plus caspofungin were evaluated for the safety and efficacy of the combination antifungal therapy to treat IFIs.

Methods

In this retrospective study, medical records were retrieved for patients admitted to the Pediatric Department of Yeungnam University Hospital, Daegu, South Korea, between April 2009 and May 2013. Medical records of 22 patients were analyzed.

Results

Of the 22 patients studied, nine (41%) had been diagnosed with probable IFI, and 13 (59%) with possible IFI. All patients, except one, were already receiving antifungal monotherapy for the treatment of neutropenic fever. After a diagnosis of IFI was confirmed, antifungal monotherapy was replaced with combination therapy. The study's overall response rate was 90.9%, with complete responses in 86.3% of the patients. Two patients experienced a side effect of a small increase in liver enzyme levels.

Conclusion

Voriconazole plus caspofungin combination therapy is an effective and safe treatment for serious IFI in pediatric patients with acute leukemia.

Pediatric haematopoiesis and related malignancies

Survival after acute paediatric (0–14 years), adolescent (15–19 years) and young adult (20–39 years) leukaemia has improved substantially over the last five decades, particularly for acute lymphoblastic leukaemia (ALL) and acute promyelocytic leukaemia. This progress represents one of the most successful achievements in the history of medicine and has been attributed to the development of effective chemotherapy regimens, improvement in supportive care, better risk stratification, use of targeted therapies, and advances in haematopoietic stem cell transplantation. Recent studies have revealed improvement in survival over time for all age groups and subtypes of leukaemia. However, these outcomes varied widely by age and are associated with sociodemographic and clinical factors. The present review concludes that survival and early death after acute leukaemia has greatly improved among young patients. However, inequalities in outcomes remain and are likely a result of multiple factors.

Biologic and clinical characteristics of adolescent and young adult cancers: Acute lymphoblastic leukemia, colorectal cancer, breast cancer, melanoma, and sarcoma

Adolescent and young adult (AYA) patients with cancer have not attained the same improvements in overall survival as either younger children or older adults. One possible reason for this disparity may be that the AYA cancers exhibit unique biologic characteristics, resulting in differences in clinical and treatment resistance behaviors. This report from the biologic component of the jointly sponsored National Cancer Institute and LiveStrong Foundation workshop entitled "Next Steps in Adolescent and Young Adult Oncology" summarizes the current status of biologic and translational research progress for 5 AYA cancers; colorectal cancer breast cancer, acute lymphoblastic leukemia, melanoma, and sarcoma. Conclusions from this meeting included the need for basic biologic, genomic, and model development for AYA cancers as well as translational research studies to elucidate any fundamental differences between pediatric, AYA, and adult cancers. The biologic questions for future research are whether there are mutational or signaling pathway differences (for example, between adult and AYA colorectal cancer) that can be clinically exploited to develop novel therapies for treating AYA cancers and to develop companion diagnostics.

Patient Characteristics and Outcomes in Adolescents and Young Adults (AYA) With Acute Myeloid Leukemia (AML)

BACKGROUND

Little is known about outcomes of acute myeloid leukemia (AML) in adolescents and young adults (AYA). The purpose of this study is to determine the characteristics and outcomes of AYA AML patients in comparison to older adult patients with AML.

PATIENTS AND METHODS

We retrospectively analyzed all AML patients treated at our institution from 1965 to 2009 who were aged 16 to 29 years.

RESULTS

Among 3922 adult AML patients treated during this period, 432 (11%) were identified as AYA. Median age was 23 years (range, 16-29 years); 73 (17%) patients had core binding factor (CBF)-AML [inversion (16), translocation (8:21)], and 51 (12%) had acute promyelocytic leukemia. Complete remission (CR) rates were 93% for CBF AML, 78% for APL, 77% with diploid karyotype, and 68% for other AML. Univariate analysis demonstrated higher rates of CR, CR duration, and overall survival (OS) in the AYA group compared with older patients. On multivariate analysis, AYA age group was independently associated with improved CR rate and CR duration, with a trend for longer OS (P = .085).

CONCLUSION

Outcome of AYA AML patients is overall better than for older adults with AML. Despite improvements in treatments and outcomes over time, there is still need for improvement in AYA with AML particularly for those with AML other than CBF and APL.

Adolescent and young adult cancer survival

Adolescent and young adults (AYAs) face challenges in having their cancers recognized, diagnosed, treated, and monitored. Monitoring AYA cancer survival is of interest because of the lack of improvement in outcome previously documented for these patients as compared with younger and older patient outcomes. AYA patients 15-39 years old, diagnosed during 2000-2008 with malignant cancers were selected from the SEER 17 registries data. Selected cancers were analyzed for incidence and five-year relative survival by histology, stage, and receptor subtypes. Hazard ratios were estimated for cancer death risk among younger and older ages relative to the AYA group. AYA survival was worse for female breast cancer (regardless of estrogen receptor status), acute lymphoid leukemia (ALL), and acute myeloid leukemia (AML). AYA survival for AML was lowest for a subtype associated with a mutation of the nucleophosmin 1 gene (NPM1). AYA survival for breast cancer and leukemia remain poor as compared with younger and older survivors. Research is needed to address disparities and improve survival in this age group.

A meta-analysis of the association between NQO1 C609T variation and acute myeloid leukemia risk

Quinone oxidoreductase (NQO1) C609T polymorphisms have been implicated in acute myeloblastic leukemia (AML) risk, but previously published studies are inconsistent and recent meta-analyses have not been adequate. To derive a more precise estimation of the relationship, a meta-analysis was performed. Medline, PubMed, Embase, and Web of Science were searched. The quality of studies was evaluated by using the Newcastle-Ottawa Scale (NOS). Crude ORs with 95% CIs were used to assess the strength of association between the NQO1 C609T polymorphisms and AML risk. A total of 14 studies including 2,245 cases and 3,310 controls were involved in this meta-analysis. Overall, significantly elevated AML risk was associated with NQO1 C609T variant genotypes when all studies were pooled into the meta-analysis (TT vs. CC: OR = 1.44, 95% CI = 1.15-1.81; dominant model: OR = 1.35, 95% CI = 1.09-1.68). In the subgroup analysis by ethnicity, significantly increased risks were found for Asians (OR = 1.47, 95% CI = 1.13-1.93, P = 0.005, I(2) = 48.4%, P = 0.071 for heterogeneity). When stratified by studies of adults or children, statistically significantly elevated risks were found among adults (OR = 1.37, 95% CI = 1.06-1.76, P = 0.017, I(2) = 42.2%, P = 0.097 for heterogeneity). The accumulated evidence indicates that NQO1 C609T seems to confer a risk factor for AML among Asians and adults. Significant between-study heterogeneity was observed, thus more studies based on larger case-control population are required to further evaluate the role of NQO1 C609T polymorphism in AML.

Methionine synthase reductase A66G polymorphism and leukemia risk: evidence from published studies

Methionine synthase reductase (MTRR) is required for the reductive methylation of cobalamin, which is the functional cofactorial form of methionine synthase (MS) in the remethylation of homocysteine to methionine. The MTRR A66G (rs1801394) polymorphism is found to be associated with decreased enzyme affinity for MTR, the gene that encodes MS, and has been widely investigated for cancer risk, including leukemia. However, the conclusions of epidemiological studies have always been contradictory. To further clarify the association of MTRR A66G polymorphism with the risk of leukemia, this meta-analysis was performed for 2913 cases and 4764 controls. Odds ratios (ORs) with 95% confidence intervals (CIs) were used to assess the strength of associations. Pooled ORs were determined for the co-dominant model (GG vs. AA, AG vs. AA), dominant model (GG + AG vs. AA) and recessive model (GG vs. AA+ AG), respectively. No significant associations were found for all comparisons in the overall pooled analysis. However, the results of stratified analyses revealed that MTRR A66G GG genotype was associated with decreased leukemia risk in the Caucasian population, in children and for acute lymphoblastic leukemia (ALL). In contrast, increased risk was observed in the Asian population and for acute myeloid leukemia (AML). This meta-analysis suggests that MTRR A66G GG is associated with decreased risk of leukemia in a Caucasian population and in children, especially for ALL.

Comprehensive assessment of the association between DNA repair gene XRCC3 Thr241Met polymorphism and leukemia risk

The XRCC3 gene has been suggested to play an important role in the pathogenesis of leukemia risk. But the findings of publications are contradictory. To derive a more precise estimation of the association, we performed a meta-analysis. The PubMed, Embase, and China National Knowledge Infrastructure (CNKI) databases were searched for case-control studies published up to August 2013. The pooled odds ratio (OR) and its corresponding 95% confidence interval (CI) were calculated by using a fixed- or random-effect model. A total of 15 case-control studies met the inclusion criteria and were selected. The pooled OR showed that there was no statistically significant association between XRCC3 Thr241Met polymorphism and leukemia risk in overall including studies, while a risky association was observed for acute myeloid leukemia (AML) (dominant model TT/TC vs. CC: OR = 1.240, 95% CI = 1.018-1.511, P = 0.032). The XRCC3 Thr241Met polymorphism might be associated with risk of leukemia in AML. More studies with larger sample sizes are needed to validate this result.

Allogeneic hematopoietic stem cell transplantation for patients with acute leukemia

OBJECTIVE

The purposes of this study were to assess the efficacy of allogeneic hematopoietic stem cell transplantation (HSCT) for acute leukemia (AL) and analyze the factors affecting the prognosis of these patients.

METHODS

The clinical and follow-up data of 93 AL patients (median age, 30 years) undergoing allogeneic HSCT in Xiangya Hospital over the past 12 years were collected, and the potential factors affecting the efficacy and prognosis of allogeneic HSCT patients were determined.

RESULTS

Hematopoietic reconstitution was achieved in 90 patients. At the last follow-up, the incidences of severe acute graft versus host disease (aGvHD) and extensive chronic GvHD (cGvHD) were 14.0% and 20.0%, the 3-year cumulative incidence of transplantation related mortality (TRM) and relapse rate were 16.8%±6.1% and 21.3%±6.7%, and the estimated 3-year overall survival (OS) and disease-free survival (DFS) of the patients were 64.6%±5.4% and 56.5%±5.5%, respectively. Univariate analysis indicated that age older than 40 years, HLA mismatch, and severe lung infection within the first 100 days after transplantation were risk factors for severe aGvHD, age older than 40 years, HLA mismatch, severe lung infection within the first 100 days after transplantation, and severe aGvHD were risk factors for TRM, high-risk AL and lack of cGvHD were risk factors for relapse (all P<0.05). Survival estimation showed that HLA mismatch, severe lung infection occurring within the first 100 days post-transplantation, high-risk AL severe aGvHD and lack of cGvHD were risk factors associated with poor prognosis (all P<0.05). Further multivariate analyses revealed that severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD were independent risk factors for unfavorable outcomes (all P<0.05).

CONCLUSIONS

Allogeneic HSCT can improve the DFS of AL patients, and severe lung infection within the first 100 days post-transplantation, severe aGvHD and lack of cGvHD are independent risk factors affecting the prognosis.

Association between CYP1A1 Ile462Val variation and acute leukemia risk: meta-analyses including 2164 cases and 4160 controls

BACKGROUND

Previously, CYP1A1 Ile462Val polymorphism has been indicated to be a risk factor for several malignancies. Increasing reports have focused on the association of CYP1A1 Ile462Val polymorphisms with susceptibility to acute leukemia and have generated controversial results. The goal of the present study was to derive a more precise estimation of the relationship.

METHODS

Relevant literature has been rigorously searched and screened. Eligible studies were identified for the period up to Apr 2012. Meta-analyses evaluating the association of CYP1A1 Ile462Val variation with acute leukemia were carried out. Subgroup analyses on ethnicity, clinical types and source of controls were further performed.

RESULTS

A total of thirteen publications including fourteen case-control studies with 2164 cases and 4160 controls were selected for analysis. The overall data indicated a significant association of CYP1A1 Ile462Val polymorphism with acute leukemia risk (Val/Val vs Ile/Ile OR = 1.49; 95% CI = 1.11-1.98; dominant model: OR = 1.26; 95% CI = 1.05-1.51; recessive model: OR = 1.38; 95% CI = 1.04-1.83). In subgroup analysis on ethnicity, increased risk was shown among mixed ethnicities (Val/Val vs Ile/Ile: OR = 2.36; 95% CI = 1.46-3.82; dominant model: OR = 1.37; 95% CI = 1.01-1.86; recessive model: OR = 2.20; 95% CI = 1.37-3.53) but not Asians or Caucasians. In subgroup analysis on clinical types, increased risk was observed in the acute lymphocytic leukemia (ALL) subgroup (Val/Val vs Ile/Ile: OR = 2.06; 95% CI = 1.42-3.01; recessive model: OR = 1.91; 95% CI = 1.32-2.76) but not in the acute myeloid leukemia (AML) subgroup.

CONCLUSION

The results of the present study suggest that CYP1A1 Ile462Val polymorphism might be a low-penetrant risk factor for acute leukemia. Subgroup analyses suggest that homozygous Val/Val alleles might modify the susceptibility to ALL.

Genomic profiling of B-progenitor acute lymphoblastic leukemia

Childhood acute lymphoblastic leukemia (ALL) is comprised of multiple subtypes defined by recurring chromosomal alterations that are important events in leukemogenesis and are widely used in diagnosis and risk stratification, yet fail to fully explain the biology of this disease. In the last 5 years, genome-wide profiling of gene expression, structural DNA alterations and sequence variations has yielded important insights into the nature of submicroscopic genetic alterations that define novel subgroups of acute lymphoblastic leukemia and cooperate with known cytogenetic alterations in leukemogenesis. Importantly, several of these alterations are important determinants of risk of relapse and are potential targets for therapeutic intervention. Here, these advances and future directions in the genomic analysis of ALL are discussed.

Improving outcomes for high-risk ALL: translating new discoveries into clinical care

High-risk (HR) acute lymphoblastic leukemia (ALL) remains one of the greatest challenges in pediatric oncology. Relapsed ALL is a leading cause of death in young people, and further improvements in outcome will required the development of therapeutic approaches directed against rational therapeutic targets, as escalation of the intensity of existing therapies is limited by toxicity. This review summarizes advances in the biology and treatment of HR and relapsed ALL presented at a symposium at the 2010 American Society for Pediatric Hematology and Oncology Annual Meeting. Analysis of large patient cohorts has identified several factors associated with HR of relapse including older age, T-lineage disease, and persisting minimal residual disease (MRD) early in therapy. As the results of salvage therapy remain poor, new treatment approaches are needed. BCR-ABL1-positive (Ph+) ALL has historically had a very poor outcome, but recent studies have demonstrated the impressive improvements in treatment outcome with the use of tyrosine kinase inhibitors (TKIs). High-resolution genomic profiling of genetic alterations and gene expression has revolutionized our understanding of the genetic basis of ALL, and has identified several alterations associated with poor outcome, including mutations of the lymphoid transcription factor gene IKZF1 (IKAROS), activating mutations of Janus kinases, and rearrangement of the lymphoid cytokine receptor gene CRLF2. These data indicated that the genetic basis of HR-ALL is multifactorial, and have also provided a new potential therapeutic option directed at JAK inhibition.

Phase I studies of AVE9633, an anti-CD33 antibody-maytansinoid conjugate, in adult patients with relapsed/refractory acute myeloid leukemia

The efficacy of anti-CD33 immunoconjugates had been previously demonstrated for gemtuzumab-ozogamicin. AVE9633 is an anti-CD33-maytansine conjugate created by ImmunoGen Inc. Phase I trials of AVE9633 were performed in patients with AML to evaluate tolerability, pharmacokinetics and pharmacodynamics. Three phase I studies of AVE9633 were performed in 54 patients with refractory/relapsed AML, evaluating drug infusion on day 1 of a 21-day cycle (Day 1 study), day 1 and 8 (Day 1/8 study) and day 1, 4 and 7 (Day 1/4/7 study) of a 28-day cycle. Toxicity was mainly allergic reaction during infusion (3 grade 3 bronchospasms). DLT was reached for the D1-D7 schedule at 150 mg/sqm (1 keratitis, 1 liver toxicity), and the MTD was set at 130 mg/sqm for this schedule. In the two other phases I, the DLT was not reached. In the Day 1/8 study, CD33 on peripheral blasts was saturated and down-modulated for doses of 75 mg/m(2) × 2 or higher, which was correlated with WBC kinetics and plasma levels of AVE9633. Decrease of DM4/CD33 ratio on the blasts surface between day 1 and 8 was the rational for evaluating day 1/4/7 schedule. This induced relatively constant DM4/CD33 levels over the first 8 days, however no activity was noted. One CRp, one PR and biological activity in five other patients were observed in this study. The Day 1 and Day 1/4/7 studies were early discontinued because of drug inactivity at doses significantly higher than CD33 -saturating doses. No myelossuppression was observed at any trial of AVE9633. The pharmacokinetics/pharmacodynamics data obtained in these studies will provide very useful information for the design of the next generation of immunoconjugates.

Tyrosine kinase inhibitor use in pediatric Philadelphia chromosome-positive acute lymphoblastic anemia

Until recently, pediatric Philadelphia chromosome-positive (Ph(+)) acute lymphoblastic leukemia (ALL) was associated with an extremely poor outcome when treated with chemotherapy alone, and only modest survival benefits were obtained with the widespread use of hematopoietic stem cell transplantation (HSCT). The development of first-generation (imatinib) and second-generation (dasatinib and nilotinib) tyrosine kinase inhibitors (TKIs) that target the BCR-ABL1 fusion protein produced by the Ph chromosome revolutionized the treatment of chronic myelogenous leukemia (CML). The Children's Oncology Group (COG) AALL0031 trial showed that the addition of imatinib to intensive chemotherapy did not cause increased toxicity and resulted in 3-year event-free survival rates that were more than double those of historical control data from the pre-imatinib era. These findings create a new paradigm for integrating molecularly targeted agents with conventional chemotherapy and call for a reassessment of the routine use of HSCT for children and adolescents with Ph(+) ALL. Second-generation TKIs have theoretical advantages over imatinib, and are now being tested in Ph(+) ALL. The focus of contemporary trials is to define the optimal use of chemotherapy, HSCT, and TKI in Ph(+) ALL. In the coming years, it is anticipated that additional agents will become available to potentiate TKI therapy and/or circumvent TKI resistance in Ph(+) ALL. Recent genomic studies have identified a subtype of high-risk pediatric B-cell-precursor ALL with a gene-expression profile similar to that of Ph(+) ALL, suggestive of active kinase signaling. Many of these Ph-like ALL cases harbor chromosome rearrangements and mutations that dysregulate cytokine receptor and kinase signaling, and these leukemias may also be candidates for TKI therapy.

New strategies in acute lymphoblastic leukemia: translating advances in genomics into clinical practice

B-precursor acute lymphoblastic leukemia (B-ALL) is the most common childhood malignancy and remains a leading cause of death in children and young adults. Current therapeutic approaches involve intensive combination chemotherapy, which fails in up to one quarter of patients. New treatment approaches directed against rational therapeutic targets are required. Recent genomic profiling of ALL has identified several genetic alterations associated with a high risk of treatment failure. Deletion or sequence mutation of the lymphoid transcription factor gene IKZF1 (IKAROS) is associated with a high rate of leukemic relapse, and testing for IKZF1 alterations at diagnosis may aid risk stratification. A subset of B-ALL patients with IKZF1 alterations have a transcriptional profile similar to BCR-ABL1-positive ALL, and these patients commonly have novel rearrangements and mutations resulting in aberrant cytokine receptor signaling and activation of kinase signaling cascades, including rearrangement of CRLF2 and activating mutations of Janus kinases (JAK1 and JAK2). JAK inhibitor therapy is under investigation in children with relapsed and refractory malignancies, including leukemia.

Summary of worldwide pediatric malignancies reported after exposure to etanercept

BACKGROUND

Concerns have been raised about a potential link between the use of TNF inhibitors and development of malignancy in the pediatric population. We examined the worldwide experience of etanercept use in pediatric patients and the occurrence of malignancies as reported from clinical trials, registry studies, post-marketing surveillance, and published scientific literature.

METHODS

All reports of "malignancy" in pediatric patients (including subjects who received etanercept before age 18 and developed a malignancy before age 22) were collected from the etanercept clinical trials database and global safety database using the Medical Dictionary for Regulatory Activities (MedDRA; v12.0) standardized MedDRA query "Malignancies" from 1998 to August 2009. Cases were collected irrespective of treatment indication. All cases were included regardless of exposure to other TNF blockers or other biologics and whether the other exposure was before or after etanercept.

RESULTS

A total of 18 potential malignancies were identified: 4 leukemias, 7 lymphomas, and 7 solid tumors. Three of the 18 malignancies remain unconfirmed. No malignancies were reported from clinical trials or the open-label extension studies in any indication in children.

CONCLUSION

The data suggest that there does not appear to be an increased risk of malignancy overall with the use of etanercept. Among etanercept-exposed patients aged 4 to 17 years, the estimated worldwide and US reporting rates for lymphoma were approximately 0.01 per 100 patient-years (1 in 10,000 pt-yrs). While the reported rate of lymphoma is higher in pediatric patients treated with etanercept than in normal children, the expected rate of lymphoma in biologic naïve JIA patients is currently unknown. The risk of TNF inhibitors in the development of malignancies in children and adolescents is difficult to assess because of the rarity of malignant events, the absence of knowledge of underlying frequency of leukemia and lymphoma in JIA, and the confounding use of concomitant immunosuppressive medications.