Structural variants involving MLLT10 fusion are associated with adverse outcomes in pediatric acute myeloid leukemia

ABSTRACT

MLLT10 gene rearrangements with KMT2A occur in pediatric acute myeloid leukemia (AML) and confer poor prognosis, but the prognostic impact of MLLT10 in partnership with other genes is unknown. We conducted a retrospective study with 2080 children and young adults with AML registered on the Children's Oncology Group AAML0531 (NCT00372593) and AAML1031 trials (NCT01371981). Transcriptome profiling and/or karyotyping were performed to identify leukemia-associated fusions associated with prognosis. Collectively, 127 patients (6.1%) were identified with MLLT10 fusions: 104 (81.9%) with KMT2A::MLLT10, 13 (10.2%) with PICALM::MLLT10, and 10 (7.9%) X::MLLT10: (2 each of DDX3X and TEC), with 6 partners (DDX3Y, CEP164, SCN2B, TREH, NAP1L1, and XPO1) observed in single patients. Patients with MLLT10 (n = 127) demonstrated adverse outcomes, with 5-year event-free survival (EFS) of 18.6% vs 49% in patients without MLLT10 (n = 1953, P < .001), inferior 5-year overall survival (OS) of 38.2% vs 65.7% (P ≤ .001), and a higher relapse risk of 76% vs 38.6% (P < .001). Patients with KMT2A::MLLT10 had an EFS from study entry of 19.5% vs 12.7% (P = .628), and an OS from study entry of 40.4% vs 27.6% (P = .361) in those with other MLLT10 fusion partners. Patients with PICALM::MLLT10 had an EFS of 9.2% vs 20% in other MLLT10- without PICALM (X::MLLT10; P = .788). Patients with PICALM::MLLT10 and X::MLLT10 fusions exhibit a DNA hypermethylation signature resembling NUP98::NSD1 fusions, whereas patients with KMT2A::MLLT10 bear aberrations primarily affecting distal regulatory elements. Regardless of the fusion partner, patients with AML harboring MLLT10 fusions exhibit very high-risk features and should be prioritized for alternative therapeutic interventions.

Optimized Cytogenetic Risk-Group Stratification of KMT2A-Rearranged Pediatric Acute Myeloid Leukemia

Comprehensive international consensus on cytogenetic risk-group stratification of KMT2A-rearranged (KMT2A-r) pediatric acute myeloid leukemia (AML) is lacking. This retrospective (2005-2016) International Berlin-Frankfurt-Münster Study Group study on 1,256 children with KMT2A-r AML aimed to validate the prognostic value of established recurring KMT2A fusions and additional cytogenetic aberrations (ACAs), and secondly, to define additional, recurring KMT2A fusions and ACAs, evaluating their prognostic relevance. Compared to our previous study, three additional, recurring KMT2A-r groups were defined: Xq24/KMT2A::SEPT6, 1p32/KMT2A::EPS15, 17q12/t(11;17)(q23;q12). Across 13 KMT2A-r groups, 5-year event-free survival probabilities varied significantly (21.8% to 76.2%; P<0.01). ACAs occurred in 46.8% of 1,200 patients with complete karyotypes, correlating with inferior overall survival (56.8% vs 67.9%; P<0.01). Multivariable analyses confirmed independent associations of 4q21/KMT2A::AFF1, 6q27/KMT2A::AFDN, 10p12/KMT2A::MLLT10, 10p11.2/KMT2A::ABI1, and 19p13.3/KMT2A::MLLT1 with adverse outcomes, but not those of 1q21/KMT2A::MLLT11 and trisomy 19 with favorable and adverse outcomes, respectively. Newly identified ACAs with independent adverse prognoses were monosomy 10, trisomies 1, 6, 16, and X, add(12p), and del(9q). Among patients with 9p22/KMT2A::MLLT3, the independent association of French-American-British-type M5 with favorable outcome was confirmed, and those of trisomy 6 and measurable residual disease at end of induction with adverse outcomes were identified. We provide evidence to incorporate the five adverse-risk KMT2A fusions into the cytogenetic risk-group stratification of KMT2A-r pediatric AML, to revise the favorable-risk classification of 1q21/KMT2A::MLLT11 to intermediate risk, and to refine risk-stratification of 9p22/KMT2A::MLLT3 AML. Future studies should validate the associations between the newly identified ACAs and outcome, and unravel the underlying biological pathogenesis of KMT2A fusions and ACAs.

CD74 is expressed in a subset of pediatric acute myeloid leukemia patients and is a promising target for therapy: a report from the Children's Oncology Group

As curative therapies for pediatric AML remain elusive, identifying potential new treatment targets is vital. We assessed the cell surface expression of CD74, also known as the MHC-II invariant chain, by multidimensional flow cytometry in 973 patients enrolled in the Children's Oncology Group AAML1031 clinical trial. 38% of pediatric AML patients expressed CD74 at any level and a comparison to normal hematopoietic cells revealed a subset with increased expression relative to normal myeloid progenitor cells. Pediatric AML patients expressing high intensity CD74 typically had an immature immunophenotype and an increased frequency of lymphoid antigen expression. Increased CD74 expression was associated with older patients with lower WBC and peripheral blood blast counts, and was enriched for t(8;21), trisomy 8, and CEBPA mutations. Overall, high CD74 expression was associated with low-risk status, however 26% of patients were allocated to high-risk protocol status and 5-year event free survival was 53%, indicating that a significant number of high expressing patients had poor outcomes. In vitro pre-clinical studies indicate that anti-CD74 therapy demonstrates efficacy against AML cells but has little impact on normal CD34+ cells. Together, we demonstrate that CD74 is expressed on a subset of pediatric AMLs at increased levels compared to normal hematopoietic cells and is a promising target for therapy in expressing patients. Given that nearly half of patients expressing CD74 at high levels experience an adverse event within 5 years, and the availability of CD74 targeting drugs, this represents a promising line of therapy worthy of additional investigation.

Information fraction estimation based on the number of events within the standard treatment regimen

For a Phase III randomized trial that compares survival outcomes between an experimental treatment versus a standard therapy, interim monitoring analysis is used to potentially terminate the study early based on efficacy. To preserve the nominal Type I error rate, alpha spending methods and information fractions are used to compute appropriate rejection boundaries in studies with planned interim analyses. For a one-sided trial design applied to a scenario in which the experimental therapy is superior to the standard therapy, interim monitoring should provide the opportunity to stop the trial prior to full follow-up and conclude that the experimental therapy is superior. This paper proposes a method called total control only (TCO) for estimating the information fraction based on the number of events within the standard treatment regimen. Based on theoretical derivations and simulation studies, for a maximum duration superiority design, the TCO method is not influenced by departure from the designed hazard ratio, is sensitive to detecting treatment differences, and preserves the Type I error rate compared to information fraction estimation methods that are based on total observed events. The TCO method is simple to apply, provides unbiased estimates of the information fraction, and does not rely on statistical assumptions that are impossible to verify at the design stage. For these reasons, the TCO method is a good approach when designing a maximum duration superiority trial with planned interim monitoring analyses.

Bortezomib with standard chemotherapy for children with acute myeloid leukemia does not improve treatment outcomes: a report from the Children's Oncology Group

New therapeutic strategies are needed for pediatric acute myeloid leukemia (AML) to reduce disease recurrence and treatment-related morbidity. The Children's Oncology Group Phase III AAML1031 trial tested whether the addition of bortezomib to standard chemotherapy improves survival in pediatric patients with newly diagnosed AML. AAML1031 randomized patients younger than 30 years of age with de novo AML to standard treatment with or without bortezomib. All patients received the identical chemotherapy backbone with either four intensive chemotherapy courses or three courses followed by allogeneic hematopoietic stem cell transplantation for high-risk patients. For those randomized to the intervention arm, bortezomib 1.3 mg/m² was given on days 1, 4 and 8 of each chemotherapy course. For those randomized to the control arm, bortezomib was not administered. In total, 1,097 patients were randomized to standard chemotherapy (n=542) or standard chemotherapy with bortezomib (n=555). There was no difference in remission induction rate between the bortezomib and control treatment arms (89% vs 91%, P=0.531). Bortezomib failed to improve 3-year event-free survival (44.8±4.5% vs 47.0±4.5%, P=0.236) or overall survival (63.6±4.5 vs 67.2±4.3, P=0.356) compared with the control arm. However, bortezomib was associated with significantly more peripheral neuropathy (P=0.006) and intensive care unit admissions (P=0.025) during the first course. The addition of bortezomib to standard chemotherapy increased toxicity but did not improve survival. These data do not support the addition of bortezomib to standard chemotherapy in children with de novo AML. (Trial registered at clinicaltrials.gov NCT01371981; https://www.cancer.gov/clinicaltrials/ NCT01371981).

Adaptive trial designs in diagnostic accuracy research

The aim of diagnostic accuracy studies is to evaluate how accurately a diagnostic test can distinguish diseased from nondiseased individuals. Depending on the research question, different study designs and accuracy measures are appropriate. As the prior knowledge in the planning phase is often very limited, modifications of design aspects such as the sample size during the ongoing trial could increase the efficiency of diagnostic trials. In intervention studies, group sequential and adaptive designs are well established. Such designs are characterized by preplanned interim analyses, giving the opportunity to stop early for efficacy or futility or to modify elements of the study design. In contrast, in diagnostic accuracy studies, such flexible designs are less common, even if they are as important as for intervention studies. However, diagnostic accuracy studies have specific features, which may require adaptations of the statistical methods or may lead to specific advantages or limitations of sequential and adaptive designs. In this article, we summarize the current status of methodological research and applications of flexible designs in diagnostic accuracy research. Furthermore, we indicate and advocate future development of adaptive design methodology and their use in diagnostic accuracy trials from an interdisciplinary viewpoint. The term "interdisciplinary viewpoint" describes the collaboration of experts of the academic and nonacademic research.

Evaluating the predictive value of measures of susceptibility to tobacco and alternative tobacco products

BACKGROUND

The "cigarette susceptibility index" has been adapted for other products, yet, the validity of these adapted measures-particularly among youth who have used other tobacco products-has not been evaluated.

METHODS

We used prospective data from the Southern California Children's Health Study to evaluate the association of questionnaire measures assessing susceptibility to e-cigarette, cigarette, hookah and cigar/cigarillo/little cigar use at wave 1 (W1; 11th/12th grade) with subsequent initiation between W1 and W2 (16 months later, N = 1453). We additionally examined whether each effect estimate differed by use of other tobacco products at W1.

RESULTS

Odds ratios, attributable risk%, and risk differences for product initiation among susceptible vs. non-susceptible youth were consistently higher among never users of any tobacco product than among youth with any tobacco use history. For example, susceptible (vs. non-susceptible) youth with no prior tobacco use had 3.64 times the odds of subsequent initiation of e-cigarettes (95%CI:2.61,5.09), while among users of another product, susceptible (vs. non-susceptible) youth had 1.95 times the odds of e-cigarette initiation (95%CI:0.98,3.89; p-interaction = 0.016). 60.4% of e-cigarette initiation among never users of any product could be attributed to susceptibility, compared to 19.8% among users of another product. The e-cigarette absolute risk difference between susceptible and non-susceptible youth was 21.9%(15.2,28.6) for never users, vs. 15.4%(0.2,30.7) for users of another product.

CONCLUSION

Tobacco product-specific susceptibility associations with initiation of use at W2 were markedly attenuated among prior users of other products, demonstrating reduced utility for these measures among subjects using other products.

Development of acute lymphoblastic leukemia following treatment for acute myeloid leukemia in children with Down syndrome: A case report and retrospective review of Children's Oncology Group acute myeloid leukemia trials

Children with Down syndrome have a 150-fold increased risk of developing acute myeloid leukemia (AML) and 20-fold increased risk of developing acute lymphoblastic leukemia (ALL). Although the risk of developing AML and ALL is significantly increased in children with Down syndrome, the development of both malignancies in the same patient is very rare. We describe a patient with Down syndrome who developed ALL 6 years after being diagnosed with AML. We performed a literature review and Children's Oncology Group query and discovered eight published cases and five cases of ALL following AML in pediatric patients with Down syndrome, as well as six cases of ALL following AML in non-Down syndrome patients. There was a similar cumulative incidence of ALL after treatment for AML in the Down syndrome and non-Down syndrome populations. Overall survival in patients with Down syndrome who developed ALL after treatment for AML was comparable to overall survival for patients with Down syndrome with de novo ALL with an average follow-up of 7 years after ALL diagnosis. Clinical data collected were used to discuss whether this phenomenon represents a secondary leukemia, second primary cancer, or mixed-lineage leukemia.

Quality of life in pediatric acute myeloid leukemia: Report from the Children's Oncology Group

INTRODUCTION

Objectives were used to describe guardian proxy-report and child self-report quality of life (QoL) during chemotherapy for pediatric acute myeloid leukemia (AML) patients.

METHODS

Patients enrolled on the phase 3 AML trial AAML1031 who were 2-18 years of age with English-speaking guardians were eligible. Instruments used were the PedsQL Generic Core Scales, Acute Cancer Module, and Multidimensional Fatigue Scale. Assessments were obtained at the beginning of Induction 1 and following completion of cycles 2-4. Potential predictors of QoL included the total number of nonhematological grade 3-4 Common Terminology Criteria for Adverse Event (CTCAE) submissions.

RESULTS

There were 505 eligible guardians who consented to participate and 348 of their children provided at least one self-report assessment. The number of submitted CTCAE toxicities was significantly associated with worse physical health summary scores (β ± standard error (SE) -3.00 ± 0.69; P < 0.001) and general fatigue (β ± SE -2.50 ± 0.66; P < 0.001). Older age was significantly associated with more fatigue (β ± SE -0.58 ± 0.25; P = 0.022). Gender, white race, Hispanic ethnicity, private insurance status, risk status, bortezomib assignment, and duration of neutropenia were not significantly associated with QoL.

DISCUSSION

The number of CTCAE toxicities was the primary factor influencing QoL among children with AML. Reducing toxicities should improve QoL; identifying approaches to ameliorate them should be a priority.

Occurrence of Treatment-Related Cardiotoxicity and Its Impact on Outcomes Among Children Treated in the AAML0531 Clinical Trial: A Report From the Children's Oncology Group

PURPOSE

Late cardiotoxicity after pediatric acute myeloid leukemia therapy causes substantial morbidity and mortality. The impact of early-onset cardiotoxicity on treatment outcomes is less well understood. Thus, we evaluated the risk factors for incident early cardiotoxicity and the impacts of cardiotoxicity on event-free survival (EFS) and overall survival (OS).

METHODS

Cardiotoxicity was ascertained through adverse event monitoring over the course of follow-up among 1,022 pediatric patients with acute myeloid leukemia treated in the Children's Oncology Group trial AAML0531. It was defined as grade 2 or higher left ventricular systolic dysfunction on the basis of Common Terminology Criteria for Adverse Events (version 3) definitions.

RESULTS

Approximately 12% of patients experienced cardiotoxicity over a 5-year follow-up, with more than 70% of incident events occurring during on-protocol therapy. Documented cardiotoxicity during on-protocol therapy was significantly associated with subsequent off-protocol toxicity. Overall, the incidence was higher among noninfants and black patients, and in the setting of a bloodstream infection. Both EFS (hazard ratio [HR], 1.6; 95% CI, 1.2 to 2.1; P = .004) and OS (HR, 1.6; 95% CI, 1.2 to 2.2, P = .005) were significantly worse in patients with documented cardiotoxicity. Impacts on EFS were equivalent whether the incident cardiotoxicity event occurred in the absence (HR, 1.6; 95% CI, 1.1 to 2.2; P = .017) or presence of infection (HR, 1.6; 95% CI, 1.0 to 2.7; P = .069) compared with patients without documented cardiotoxicity. However, the reduction in OS was more pronounced for cardiotoxicity not associated with infection (HR, 1.7; 95% CI, 1.2 to 2.5; P = .004) than for infection-associated cardiotoxicity (HR, 1.3; 95% CI, 0.7 to 2.4; P = .387).

CONCLUSION

Early treatment-related cardiotoxicity may be associated with decreased EFS and OS. Cardioprotective strategies are urgently needed to improve relapse risk and both short- and long-term mortality outcomes.

High Acceptability of Human Papillomavirus Self-Sampling Among Nonattenders of a Public Cervical Cancer Screening Program in El Salvador

Abstract 29

Purpose

In high-income countries, human papillomavirus (HPV) self-sampling has been demonstrated to increase adherence to cervical cancer prevention initiatives in underscreened women. El Salvador recently completed the Cervical Cancer Prevention in El Salvador (CAPE) program using a high-risk HPV test as the screening method. Although successful, 12% of targeted women did not attend their screening appointments. HPV self-sampling may offer the opportunity to reach these nonattending women. In the current study, we evaluated HPV self-sampling as a way to increase screening among CAPE nonattenders and to report factors that impact self-sampling acceptability in a low- to middle-income country.

Methods

Nonattending and underscreened women age 30 to 59 years from the Paracentral region of El Salvador were invited to participate (N = 2,019). Women were visited at home and offered self-sampling with an HPV test. Women who provided consent also received a series of questionnaires to collect demographic and test acceptability data. After tests were analyzed, women were provided with results during another home visit. HPV-positive women were asked to make an appointment at a local clinic to undergo colposcopy, biopsy, and, if eligible, cryotherapy treatment. Women with contraindications for cryotherapy were referred to appropriate treatment or follow-up.

Results

Of 1,989 eligible women, 94% accepted the HPV self-sampled test. Of these, 11.8% (n = 221) tested positive. All but 13 women attended the colposcopy appointment, and 190 women received cryotherapy. Biopsy results revealed low-grade precancer in 6.3% of women, whereas 12.6% received diagnoses of high-grade precancer. Reasons for not attending the original CAPE appointment included logistic concerns, but also discomfort with male providers, confidentiality fears, and misconceptions regarding HPV, cervical cancer, and the screening procedure.

Conclusion

HPV self-sampling was shown to be overwhelmingly acceptable to nonattending and underscreened rural women in El Salvador. This method may be a feasible alternative that circumvents barriers to cervical cancer screening in low- to middle-income countries.

AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST

No COIs from the authors

Early discharge as a mediator of greater ICU-level care requirements in patients not enrolled on the AAML0531 clinical trial: a Children's Oncology Group report

Previous data suggest that patients enrolled on clinical trials for treatment of cancer have better overall survival than patients who do not enroll; however, short‐term outcomes relative to trial enrollment and corresponding mediators have not been assessed. A cohort of pediatric patients with newly‐diagnosed acute myeloid leukemia was assembled from the Pediatric Health Information System. We evaluated whether patients not enrolled onto Children's Oncology Group trial AAML0531 had greater intensive care unit (ICU)‐level requirements than enrolled patients and whether early discharge after chemotherapy administration mediated this association. Patients not enrolled on AAML0531 were more likely to be discharged early (aOR = 1.40, 95% confidence interval [CI]: 1.02, 1.90) and to require ICU‐level care (aOR = 2.00, 95% CI: 1.06, 3.78) than enrolled patients, but early discharge explained only a small proportion (12.3%) of the absolute difference in ICU‐level care risk. The direct effect of nonenrollment on the need for ICU‐level care was significant (aOR = 1.89, 95% CI: 1.00, 3.94), whereas the indirect effect mediated through early discharge was not (aOR = 1.07, 95% CI: 0.95, 1.19). Factors other than postchemotherapy discharge strategy drive the difference in ICU utilization by trial enrollment status.

Adapting CryoPen, a Non-Gas Based Cryotherapy System for Use in Low- and Middle-Income Countries

Abstract 45

Background:

Cervical cancer is a leading cause of cancer-related mortality among women in low- and middle-income countries (LMICs). Two point-of-care technologies that address the treatment gap are the LMIC-adapted CryoPen, with a core temperature of approximately −95°C, and the thermocoagulator, with a probe temperature of 100-120°C. Since there is scant data on the extent of CIN involvement in an underscreened population, determining mean cervical intraepithelial neoplasia (CIN) depth in an underscreened population will establish the depth of necrosis (DON) that ablative techniques need to achieve. The study aimed to establish the maximum depth of involvement of CIN3 and test whether the LMIC-adapted CryoPen and thermocoagulator reach the DON established as necessary for eradicating CIN3.

Methods:

A convenience sample of 107 CIN3 cases were reviewed by a pathologist at the National Cancer Institute (INEN, Peru) and a U.S. pathologist. Ten women had ablative procedures before non-cervical pathology indicated hysterectomy: a five-minute freeze with the CryoPen (n=5), or a 60-second, 100°C application of the thermocoagulator (n=5). The pathologists measured mean depth of involvement in the CIN3 cases and the local pathologist, blinded to ablative technique, measured maximum DON in both lips.

Results:

Mean depth of CIN3 involvement was 2.0mm among 107 cases. Mean depth was ≤3.0mm among 79.4%; ≤3.5mm among 89.7%; ≤4.0mm among 93.5%; and ≥5.0mm among 6.5%. The maximum DON achieved by the LMIC-adapted CryoPen was ≥3.0 in 80% of cases; ≥3.5mm in 80%; ≥4.0mm in 80%; ≥4.5mm in 40%; and ≥5.0mm in 20%. The maximum DON achieved by the thermocoagulator was ≥3.0mm in 80% of cases; ≥3.5mm in 80%; ≥4.0mm in 20%; and ≥4.5mm in 20%.

Conclusion:

The pathology review of CIN3 cases showed that 90% of CIN3 would be eradicated if DON reached at least 3.5mm. The mean DON of both the LMIC-adapted CryoPen and thermocoagulator exceeded 3.5mm.

AUTHORS' DISCLOSURES OF POTENTIAL CONFLICTS OF INTEREST:

Miriam Cremer No relationship to disclose Mauricio Maza No relationship to disclose Albert Zevallos No relationship to disclose Manuel Alvarez No relationship to disclose Luis Taxa No relationship to disclose Philip E. Castle Honoraria: Roche Cepheid Consulting or Advisory Role: Cepheid, GE Healthcare, Guided Therapeutics, ClearPath, Merck, Genticel, Teva, Inovio Pharmaceuticals, Hologic Todd Alonzo No relationship to disclose Juan Felix No relationship to disclose

Clinical Impact of Additional Cytogenetic Aberrations, cKIT and RAS Mutations, and Treatment Elements in Pediatric t(8;21)-AML: Results From an International Retrospective Study by the International Berlin-Frankfurt-Münster Study Group

PURPOSE

This retrospective cohort study aimed to determine the predictive relevance of clinical characteristics, additional cytogenetic aberrations, and cKIT and RAS mutations, as well as to evaluate whether specific treatment elements were associated with outcomes in pediatric t(8;21)-positive patients with acute myeloid leukemia (AML).

PATIENTS AND METHODS

Karyotypes of 916 pediatric patients with t(8;21)-AML were reviewed for the presence of additional cytogenetic aberrations, and 228 samples were screened for presence of cKIT and RAS mutations. Multivariable regression models were used to assess the relevance of anthracyclines, cytarabine, and etoposide during induction and overall treatment. End points were the probability of achieving complete remission, cumulative incidence of relapse (CIR), probability of event-free survival, and probability of overall survival.

RESULTS

Of 838 patients included in final analyses, 92% achieved complete remission. The 5-year overall survival, event-free survival, and CIR were 74%, 58%, and 26%, respectively. cKIT mutations and RAS mutations were not significantly associated with outcome. Patients with deletions of chromosome arm 9q [del(9q); n = 104] had a lower probability of complete remission (P = .01). Gain of chromosome 4 (+4; n = 21) was associated with inferior CIR and survival (P < .01). Anthracycline doses greater than 150 mg/m(2) and etoposide doses greater than 500 mg/m(2) in the first induction course and high-dose cytarabine 3 g/m(2) during induction were associated with better outcomes on various end points. Cumulative doses of cytarabine greater than 30 g/m(2) and etoposide greater than 1,500 mg/m(2) were associated with lower CIR rates and better probability of event-free survival.

CONCLUSION

Pediatric patients with t(8;21)-AML and additional del(9q) or additional +4 might not be considered at good risk. Patients with t(8;21)-AML likely benefit from protocols that have high doses of anthracyclines, etoposide, and cytarabine during induction, as well as from protocols comprising cumulative high doses of cytarabine and etoposide.

MDM2 polymorphism increases susceptibility to childhood acute myeloid leukemia: a report from the Children's Oncology Group

BACKGROUND

The variant polymorphism in the gene MDM2, SNP309, leads to increased level of mdm2 protein and subsequent downregulation of p53 tumor suppressor pathway. Presence of this single nucleotide polymorphism (SNP) has been associated with earlier tumorigenesis in patients with Li-Fraumeni syndrome, as well as decreased survival in patients with CLL. In addition, cells homozygous (G/G) for SNP 309 were found to have 10-fold increase resistance to topoisomerase II inhibitors in vitro.

PROCEDURE

We genotyped children (n = 575) with de novo acute myeloid leukemia (AML) treated on three Children's Oncology Group protocols (CCG 2941/2961/AAML 03P1) for the presence of SNP309. Healthy blood donors were genotyped as control population.

RESULTS

The variant G/G genotype was associated with an increased susceptibility to AML (OR 1.5; P = 0.049). However, the presence of the variant allele at SNP309 did not modify disease response or toxicity in children treated on CCG protocols 2941/2961.

CONCLUSIONS

The variant SNP 309 influences susceptibility to pediatric AML, but does not impact overall response to therapy.

Treatment of children with acute promyelocytic leukemia: results of the first North American Intergroup trial INT0129

BACKGROUND

This report focuses on the children enrolled on the first North American Intergroup study of APL (INT0129). This study was designed to compare the rates of CR, disease-free survival (DFS), overall survival (OS) and toxicity of therapy with all-trans-retinoic acid (ATRA) for remission induction and/or maintenance compared to conventional chemotherapy in patients with previously untreated APL.

PROCEDURE

Fifty-three patients who were documented to have the t(15;17) translocation were able to be evaluated for toxicity of treatment, outcome of induction, and survival.

RESULTS

The overall CR rate was 81%. The estimated 5-year DFS from time of CR was 41% for all patients. The estimated 5-year OS for all patients from entry into the study was 69%. The 5-year DFS from time of CR for patients who were randomized to ATRA for induction or maintenance or both was 48% compared to 0% for patients who never received ATRA (P < 0.0001).

CONCLUSIONS

The most important finding of our study is that a significant DFS advantage exists for children with APL who received ATRA during induction or maintenance or both compared to children who received no ATRA. Furthermore, remissions in these children appear durable as the OS rates are stable at 10 years.

Extramedullary leukemia in children with newly diagnosed acute myeloid leukemia: a report from the Children's Cancer Group

OBJECTIVES

To describe features of patients with acute myeloid leukemia presenting with extramedullary leukemic tumors (EML).

METHODS

Among 1,832 patients entered on Children's Cancer Group's chemotherapy trials with acute myeloid leukemia, 199 patients had EML, defined as any leukemic collection outside the bone marrow cavity. Three patient groups were denoted: group 1 (n=109) with EML involving skin (with or without other sites of EML), group 2 (n=90) with EML in sites other than skin, and group 3 (n=1,633) without EML.

RESULTS

The incidence of EML was 10.9%. Group 1 patients tended to be younger, had higher white blood cell counts, were more often CNS positive, had FAB M4 or M5 subtypes, and possessed more abnormalities of chromosome 11 than group 3 patients. Group 2 patients were younger, more often had the FAB M2 subtype, and had a higher incidence of t(8;21)(q22;q22) abnormality than group 3, but had similar white blood cell counts and incidence of CNS positivity at diagnosis. For group 1 the 5-year event-free survival was 26%, significantly worse than for group 3 at 29%. Event-free survival was better for group 2 patients (5-year estimate 46%), which remained a favorable prognostic factor by multivariate analysis. The authors retrospectively determined whether 118 (59%) of the EML patients received localized radiotherapy to the site of EML: 42 did and 76 did not. There were no differences in estimated event-free survival between patients who did and did not receive radiotherapy.

CONCLUSIONS

Non-skin (group 2) EML appeared to be an independent favorable prognostic factor. Localized radiotherapy to the site of EML at the end of induction chemotherapy did not improve outcome.

Effects of intraoral splint wear on proteoglycans in the temporomandibular joint disc

Intraoral splints are a common dental treatment for dysfunctions of the temporomandibular joint (TMJ), but their effects on the structures of the joint, specifically the disc, have not been well investigated. This study examined proteoglycans (PGs) of the TMJ disc of the miniature pig and tested for alterations resulting from intraoral splint wear. Sixteen female pigs were divided into three groups: control (C), control splint (CS), and protrusive splint (PS). Splinted groups received chrome-cobalt ramp splints which were worn continuously for 2 months. PG content within various disc locations was determined by colorimeteric assay. PG synthesis and type were examined by labeling with (35)S-sulfate and SDS-PAGE analysis. Average water content of the disc was 77.1%, which places it at the high end of the normal range for collagenous biomaterials (60-80%). PGs migrating to the positions typical of aggrecan, biglycan, and decorin on SDS-PAGE were present in all locations of all groups. The highest content and synthesis of PGs were always found in the intermediate band of the disc regardless of group (P < 0.05), supporting the notion that this band encounters heavy compressive loading during function. The joints of animals from both splinted groups showed a high frequency of gross pathology. Biglycan synthesis was increased in both splinted groups (P < 0.05). Newly synthesized biglycan had a shorter migration distance in the intermediate bands of the CS group, suggesting increased hydrodynamic size. These findings suggest that intraoral splint wear may cause disc damage or remodeling.

Comparisons of predictive values of binary medical diagnostic tests for paired designs

Positive and negative predictive values of a diagnostic test are key clinically relevant measures of test accuracy. Surprisingly, statistical methods for comparing tests with regard to these parameters have not been available for the most common study design in which each test is applied to each study individual. In this paper, we propose a statistic for comparing the predictive values of two diagnostic tests using this paired study design. The proposed statistic is a score statistic derived from a marginal regression model and bears some relation to McNemar's statistic. As McNemar's statistic can be used to compare sensitivities and specificities of diagnostic tests, parameters that condition on disease status, our statistic can be considered as an analog of McNemar's test for the problem of comparing predictive values, parameters that condition on test outcome. We report on the results of a simulation study designed to examine the properties of this test under a variety of conditions. The method is illustrated with data from a study of methods for diagnosis of coronary artery disease.

Building community for the long-term: an intergenerational commitment

Intergenerational visitation programs have demonstrated advantages for the young and old, but few programs last more than a year or two. Weaving long-term intergenerational programs into the fabric of both school curricula and community cultural life was the goal of a project launched in 1988 in Phoenix, Arizona. Classrooms of children visit weekly or biweekly with nearby nursing home residents, developing friendships while pursuing educational activities. Carefully planned and widespread community support through board participation, donations, and publicity has allowed the program to continue to expand, while the budget has decreased. Materials are available which facilitate program replication.