Association of body mass index and survival in pediatric leukemia: a meta-analysis

BACKGROUND

Obesity is a worldwide epidemic in children and adolescents. Adult cohort studies have reported an association between higher body mass index (BMI) and increased leukemia-related mortality; whether a similar effect exists in childhood leukemia remains controversial.

OBJECTIVE

We conducted a meta-analysis to determine whether a higher BMI at diagnosis of pediatric acute lymphoblastic leukemia (ALL) or acute myeloid leukemia (AML) is associated with worse event-free survival (EFS), overall survival (OS), and cumulative incidence of relapse (CIR).

DESIGN

We searched 4 electronic databases from inception through March 2015 without language restriction and included studies in pediatric ALL or AML (0-21 y of age) reporting BMI as a predictor of survival or relapse. Higher BMI, defined as obese (≥95%) or overweight/obese (≥85%), was compared with lower BMI [nonoverweight/obese (<85%)]. Summary risk estimates for EFS, OS, and CIR (ALL only) were calculated with random- or fixed-effects models according to tests for between-study heterogeneity.

RESULTS

Of 4690 reports identified, 107 full-text articles were evaluated, with 2 additional articles identified via review of citations; 11 articles were eligible for inclusion in this meta-analysis. In ALL, we observed poorer EFS in children with a higher BMI (RR: 1.35; 95% CI: 1.20, 1.51) than in those at a lower BMI. A higher BMI was associated with significantly increased mortality (RR: 1.31; 95% CI: 1.09, 1.58) and a statistically nonsignificant trend toward greater risk of relapse (RR: 1.17; 95% CI: 0.99, 1.38) compared with a lower BMI. In AML, a higher BMI was significantly associated with poorer EFS and OS (RR: 1.36; 95% CI: 1.16, 1.60 and RR: 1.56; 95% CI: 1.32, 1.86, respectively) than was a lower BMI.

CONCLUSION

Higher BMI at diagnosis is associated with poorer survival in children with pediatric ALL or AML.

Effect of Sensorineural Hearing Loss on Neurocognitive Functioning in Pediatric Brain Tumor Survivors

BACKGROUND

Intensified therapy with platinum-based regimens for pediatric brain tumors has dramatically increased the number of pediatric brain tumor survivors (PBTS) but frequently causes permanent sensorineural hearing loss (SNHL). Although neurocognitive decline in PBTS is known to be associated with radiation therapy (RT), SNHL represents a potential additional contributor whose long-term impact has yet to be fully determined.

METHODS

The neurocognitive impact of significant SNHL (Chang scale ≥ 2b) in PBTS was assessed through a retrospective cohort study of audiograms and neurocognitive testing. Scores for neurocognitive domains and subtest task performance were analyzed to identify specific strengths and weakness for PBTS with SNHL.

RESULTS

In a cohort of PBTS (n = 58) treated with platinum therapy, significant SNHL was identified in more than half (55%, n = 32/58), of which the majority required hearing aids (72%, 23/32). RT exposure was approximately evenly divided between those with and without SNHL. PBTS were 6.7 ± 0.6 and 11.3 ± 0.7 years old at diagnosis and neurocognitive testing, respectively. In multivariate analyses adjusted for RT dose, SNHL was independently associated with deficits in intelligence, executive function, and verbal reasoning skills. Subtests revealed PBTS with SNHL to have poor learning efficiency but intact memory and information acquisition.

CONCLUSIONS

SNHL in PBTS increases the risk for severe therapy-related intellectual and neurocognitive deficits. Additional prospective investigation in malignant brain tumors is necessary to validate these findings through integration of audiology and neurocognitive assessments and to identify appropriate strategies for neurocognitive screening and rehabilitation specific to PBTS with and without SNHL.

Abstract 2185: Childhood obesity is associated with persistent minimal residual disease (MRD) following induction therapy for pediatric acute lymphoblastic leukemia

Background: The epidemic of childhood obesity poses substantial treatment challenges for the care of children with acute lymphoblastic leukemia (ALL). Obesity at time of diagnosis of ALL is associated with worse survival as well as treatment-related morbidity. Inability to achieve a deep initial remission following Induction as evidenced by persistent MRD in the bone marrow is associated with poor survival and has thus become the predominant modern prognostic indicator. We therefore hypothesized that obesity at time of diagnosis of ALL is associated with MRD positivity at the end-of-Induction disease evaluation.

Methods: In a cohort of children 1 - 20 years old treated for B-precursor ALL (BP-ALL) at our institution from 2008 to 2013 on Children's Oncology Group (COG) treatment regimens, we examined MRD at end-of-Induction as determined by multidimensional flow cytometry. A threshold of 0.01% was used to determine MRD positive versus negative as per COG regimens. Overweight and obese categories were defined as 85-95th and ≥95th percentile for body mass index (BMI) according to the CDC population norms. Logistic regression analyses were performed controlling for age, gender, ethnicity/race, presence/absence of Down Syndrome (due to the high prevalence of obesity), National Cancer Institute (NCI) risk category, cytogenetic classification (standard, favorable, unfavorable, unknown), and CNS status at diagnosis. BMI was evaluated as both a continuous variable and also as per normal, overweight, obese categories.

Results: We identified 198 patients with BP-ALL and evaluable MRD, 119 with NCI SR-ALL and 79 with NCI HR-ALL. Of these, 55 (27.8%) had positive MRD at end-of-Induction [27 SR-ALL (22.7%), 28 HR-ALL (35.4%). In the obese group, 45.2% (19/42) were MRD+, compared to only 22.8% (29/127) of normal weight and 24.1% (7/29) of overweight patients. After controlling for above covariates, obese patients had a statistically significantly increased risk for MRD positivity at end-of-Induction [Odds Ratio (OR) 2.64, 95 percent Confidence Interval (95%CI) 1.13-6.19, p=0.025]. Similarly, each percentile increase in BMI significantly corresponded to an increased risk for MRD positivity (OR 1.08, 95%CI 1.00-1.17, p=0.046).

Conclusion: Obese children at diagnosis of BP-ALL are at significantly increased risk for persistent MRD in the bone marrow at end-of-Induction. With the established strong adverse association of persistent MRD with poorer survival, this implies that obesity adversely influences survival as early as this initial phase of treatment. Our results support the need for further research into mechanisms underlying this phenomenon and potential up-front strategies to improve efficiency of remission induction in this population.

Citation Format: Etan Orgel, Jonathan Tucci, Wassem Alhushki, David R. Freyer, Hisham Abdel-Azim, Steven D. Mittelman. Childhood obesity is associated with persistent minimal residual disease (MRD) following induction therapy for pediatric acute lymphoblastic leukemia. [abstract]. In: Proceedings of the 105th Annual Meeting of the American Association for Cancer Research; 2014 Apr 5-9; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2014;74(19 Suppl):Abstract nr 2185. doi:10.1158/1538-7445.AM2014-2185

Impact on survival and toxicity by duration of weight extremes during treatment for pediatric acute lymphoblastic leukemia: A report from the Children's Oncology Group

PURPOSE

Previous studies regarding the influence of weight on event-free survival (EFS) and treatment-related toxicity (TRT) in childhood acute lymphoblastic leukemia (ALL) considered only weight at diagnosis. Inasmuch as weight varies substantially over treatment, we hypothesized its impact on EFS is instead determined by cumulative time spent at an extreme weight during therapy and on TRT by weight at the time of toxicity.

PATIENTS AND METHODS

In a cohort of 2,008 children treated for high-risk ALL in Children's Oncology Group study CCG-1961, we determined the effect on EFS of cumulative time receiving therapy at an extreme weight (either obese or underweight) between end of induction and start of maintenance therapy. We also evaluated the association between weight category and incidence and patterns of TRT during 13,946 treatment courses.

RESULTS

Being obese or underweight at diagnosis and for ≥ 50% of the time between end of induction and start of maintenance therapy resulted in inferior EFS (hazard ratios, 1.43 and 2.30, respectively; global P < .001). Normalization of weight during that period resulted in mitigation of this risk comparable to never being obese or underweight. Obese or underweight status at start of each treatment course was significantly associated with specific patterns of TRT.

CONCLUSION

Influence of weight extremes on EFS and TRT is not set at diagnosis as previously reported but is moderated by subsequent weight status during intensive postinduction treatment phases. These observations suggest that weight is a potentially addressable risk factor to improve EFS and morbidity in pediatric ALL.

Efficacy and tolerability of intravenous pentamidine isethionate for Pneumocystis jiroveci prophylaxis in a pediatric oncology population

Cancer therapy routinely requires Pneumocystis jiroveci prophylaxis. In those intolerant of trimethoprim/sulfamethoxazole, aerosolized pentamidine is convenient and effective. Intravenous pentamidine is often substituted in young children but its efficacy remains controversial. In this retrospective study of a large pediatric oncology cohort, we confirm intravenous pentamidine to be effective and well-tolerated as second-line prophylaxis across all ages.

Why Healthcare Providers Should Focus on the Fertility of AYA Cancer Survivors: It's Not Too Late!

Reproductive health among cancer survivors is an important quality of life issue. Certain cancer therapies have known fertility risks. There is an existing cohort of adolescents and young adults (AYA) cancer survivors that, seen less frequently in clinical care settings than active patients, are likely not having discussions of fertility and other reproductive health issues. A survivor or healthcare provider can easily assume that the window of opportunity for fertility preservation has passed, however emerging research has shown this may not be the case. Recent data demonstrates a close relationship between fertility and other late effects to conclude that ongoing assessment during survivorship is warranted. Some fertility preservation procedures have also been shown to mitigate common late effects. This review explores the link between late effects from treatment and common comorbidities from infertility, which may exacerbate these late effects. This review also highlights the relevance of fertility discussions in the AYA survivorship population.

Early cardiac outcomes following contemporary treatment for childhood acute myeloid leukemia: a North American perspective

BACKGROUND

Anthracycline agents are used for treatment of acute myeloid leukemia (AML) but may cause late-onset cardiomyopathy. Current frontline therapy for AML in North America, as reflected in the approach of the Children's Oncology Group (COG) and other pediatric consortia, is adapted from the anthracyline-intensive Medical Research Council (MRC) regimen. The purpose of this study was to describe early post-treatment cardiac function as a potential indicator of acute and long-term risk associated with this approach.

PROCEDURE

A multi-center retrospective cohort analysis was conducted of AML survivors diagnosed from 2004 to 2009 and treated with MRC-based regimens. Change in left ventricular shortening fraction (LVSF) on echocardiogram was determined from baseline to latest post-treatment/pre-relapse value; associations with potential predictors were examined.

RESULTS

This cohort of pediatric survivors (n = 52) was assessed at a median interval of 13 months from end of treatment. Mean cumulative anthracycline dose was 339 ± 14 mg/m(2) . Mean baseline and post-treatment LVSF were 39.3 ± 0.8% and 35.4 ± 0.9%, respectively; mean percent change for individuals was -8.4 ± 2.8% (P < 0.001). Cardiac-directed medications were initiated in four patients (7.7%). Decline in LVSF was significantly associated with cumulative anthracycline dose, increasing BMI and Hispanic ethnicity.

CONCLUSION

Early, significant decline in LVSF was observed following treatment with these MRC-based regimens. Elevated BMI and Hispanic ethnicity were identified as new independent risk factors. Children and adolescents so treated are at substantial risk for late-onset cardiomyopathy, require monitoring with annual echocardiogram per current COG survivorship guidelines, and are good candidates for appropriate cardioprotection strategies.

The links between insulin resistance, diabetes, and cancer

The growing epidemic of obesity has resulted in a large increase in multiple related diseases. Recent evidence has strengthened the proposed synergistic relationship between obesity-related insulin resistance (IR) and/or diabetes mellitus (DM) and cancer. Within the past year, many studies have examined this relationship. Although the precise mechanisms and pathways are uncertain, it is becoming clear that hyperinsulinemia and possibly sustained hyperglycemia are important regulators of not only the development of cancer but also of treatment outcome. Further, clinical decision-making regarding the treatment of choice for DM will likely be impacted as we learn more about the non-metabolic effects of the available hyperglycemic agents. In our review, we endeavored to synthesize the recent literature and provide a concise view of the journey from macro-level clinical associations to specific mechanistic relationships being elucidated in cell lines and animal models.

Hearing loss among survivors of childhood brain tumors treated with an irradiation-sparing approach

BACKGROUND

Intensive, irradiation-sparing chemotherapy regimens for malignant brain tumors have improved survival and neurocognitive outcomes in very young children. Platinum compounds are pivotal to this approach's success but are associated with hearing loss that markedly reduces quality of life for survivors. The purpose of this study was to determine the prevalence and severity of ototoxicity associated with Head Start and similar irradiation-sparing regimens.

PROCEDURE

A retrospective cohort study was conducted of children treated for malignant brain tumors at Children's Hospital Los Angeles using irradiation-sparing regimens. Patient and treatment characteristics were ascertained. Primary outcomes were post-treatment hearing status, need for hearing aids, and hearing threshold change.

RESULTS

Twenty-nine patients were evaluable. The most common diagnosis was medulloblastoma (n = 14). The median age at diagnosis was 2.0 years (range, 0.2-9.2). Median time from diagnosis to most recent hearing assessment was 1.1 years (mean 2.4; range, 0.2-17.5). Cumulative cisplatin and carboplatin dose was 281 ± 88 mg/m(2) and 1,205 ± 277 mg/m(2) , respectively. All patients had aminoglycoside exposure. Following treatment, 18 patients (62.1%) had abnormal hearing and 11 (37.9%) required hearing aids. At 4,000 Hz, statistically significant hearing loss was documented in the range of 30-40 dB.

CONCLUSIONS

While eliminating cranial irradiation has dramatically improved survival and neurocognitive and neuroendocrine outcomes in this population, clinically significant hearing loss is now the leading late effect due to the necessity of platinum-based chemotherapy. Our results document the need for audiometric monitoring and developing otoprotective strategies in this vulnerable population.

A failing medical educational model: a self-assessment by physicians at all levels of training of ability and comfort to deliver bad news

OBJECTIVE

Patient surveys consistently show physician communication remains less than ideal. While previous studies have demonstrated a lack of trainee confidence in delivering bad news, our study explores communication skills at all levels of practice and highlights potential barriers to improvement.

METHODS

Pediatric residents, fellows, and attendings involved in direct patient care at a major academic center participated in a voluntary questionnaire, consisting of self-assessed scales of comfort level, knowledge level, amount of training, and attitudes towards communication education. We also elicited barriers to learning and teaching as well as significant experiences.

RESULTS

Eligible responses (n = 253) were evenly divided between trainees and faculty. Almost half of attendings and two thirds of fellows did not feel sufficiently knowledgeable to deliver bad news. Many attendings felt disproportionately more comfortable than they felt knowledgeable. All trainees felt insufficiently knowledgeable for independent practice of this skill. Educational barriers centered on time constraints, a deemphasis, a lack of positive modeling, and minimal awareness of existing resources. Poor experiences revolved around inappropriate language and settings as well as insufficient empathy or preparedness. Positive anecdotes highlighted the importance of education and the impact of role models.

CONCLUSION

Independent of level of training, this study reveals a lack of self-assessed preparedness from many responsible for delivering bad news to patients and families. A significant barrier to improvement is the disproportionate level of self-assessed comfort versus knowledge level. Educational models should include both didactics to learn the skills and practice-based learning to refine the techniques.