Late effects and quality of life of childhood cancer survivors: Part 2. Impact of radiotherapy

The paradigm of total body irradiation in acute lymphoblastic leukaemia: Therapeutic effectiveness versus the challenges of toxicity

INTRODUCTION

Total body irradiation (TBI) is part of the myeloablative conditioning for hematopoietic stem cell transplantation (HSCT) in malignant hematologic disorders. This therapy has recently shown improved survival in acute lymphoblastic leukemia (ALL) compared to chemotherapy-based regimens. However, side effects are a significant limitation, especially in the pediatric population.

PATIENTS AND METHODS

We retrospectively analyzed the survival of patients with ALL who underwent an HSCT at a tertiary hospital between 1996 and 2009 (N = 69 HSCT in 57 patients). We differentiated a cohort that received TBI (N = 44) from another that did not (N = 25). Subsequently, we interviewed the survivors from the TBI group with a minimum of 10 years of follow-up (N = 18), asking about the presence of side effects.

RESULTS

The overall survival (OS) at 2 and 5 years was 79.1% and 65.2% respectively for the TBI group and 66.2% and 55.8% for the non-TBI group, although this difference was not significant (P=.31). The event-free survival (EFS) at 2 and 5 years was 77.3% and 63.6% respectively for the TBI group and 56% and 32% for the non-TBI group (P=.02). The probability of relapse (PR) at 2 years for those who received TBI was 10% compared to 28.6% for those who did not receive TBI (P=.005). Survivors who received TBI developed secondary neoplasms (39%), dyslipidemia (67%), cognitive impairments affecting memory (44%), recurrent respiratory infections (39%), thyroid abnormalities (45%), premature ovarian failure (89%), cataracts (22%), and psychological problems (44%). However, the quality of life, as self-assessed by the patients, was considered good for 83% of the participants..

CONCLUSIONS

Patients who received TBI had significantly higher EFS and lower PR. However, adverse effects are frequent and significant, although they do not subjectively affect quality of life.

Proton beam therapy in paediatric cancer: Anticipating the opening of the Australian Bragg Centre for Proton Therapy and Research

Proton Beam Therapy (PBT) has the potential to improve paediatric cancer care by reducing radiation exposure and thus long-term toxicities. Ethical concerns and debates surrounding the treatment, such as eligibility and accessibility, are ongoing in Australia. The Australian Bragg Centre for Proton Therapy and Research (ABCPTR) (named after Sir William Henry Bragg who described the Bragg peak in his laboratory at the University of Adelaide in 1903) aims to increase access to PBT in Australasia and offer a patient-centred care approach. Research is underway to assess PBT's safety and cost-effectiveness, using tools including Normal Tissue Complication Probability (NTCP) models. Collaborative efforts are focused on developing tailored survivorship clinics to enhance patient follow-up and quality of life. With the anticipated opening of the ABCPTR, Australia is preparing to take a significant step in radiation oncology, offering new research opportunities and creating a publicly funded treatment centre. The initiative aims to balance treatment efficacy with patient care, setting the stage for a future in which radiation therapy will reduce long-term side effects compared to the current standard of care. The implementation of PBT in Australia represents a complex and promising approach to paediatric oncology. This article provides an overview of the current landscape, highlighting the potential benefits and challenges of a treatment that could redefine the quality of survivorship and contribute to global research and best clinical practice.

Complications after proton radiotherapy in children, focusing on severe late complications. A complete Swedish cohort 2008-2019

BACKGROUND

Proton radiotherapy (RT) is an attractive tool to deliver local therapy with minimal dose to uninvolved tissue, however, not suitable for all patients. The aim was to explore complications, especially severe late complications (grades 3-4), following proton RT delivered to a complete Swedish cohort of paediatric patients aged <18 years treated 2008-2019.

MATERIAL AND METHODS

Data was downloaded from a national registry. Complications with a possible causation with RT are reported. Proton treatments until July 2015 was performed with a fixed horizontal 172 MeV beam (The Svedberg Laboratory (TSL), Uppsala) in a sitting position and thereafter with gantry-based pencil-beam scanning technique (Skandion Clinic, Uppsala) in a supine position.

RESULTS

219 courses of proton RT (77 at TSL and 142 at Skandion) were delivered to 212 patients (mean age 9.2 years) with various tumour types (CNS tumours 58%, sarcomas 26%, germ cell tumours 7%). Twenty-five patients had severe acute complications (skin, mucous membrane, pharynx/oesophagus, larynx, upper gastrointestinal canal, lower gastrointestinal canal, eyes, ears). Fifteen patients had severe late complications; with increased proportion over time: 4% at 1-year follow-up (FU), 5% at 3-year, 11% at 5-year. Organs affected were skin (1 patient), subcutaneous tissue (4), salivary glands (1), upper GI (1), bone (7), joints (2), CNS (2), PNS (1), eyes (1) and ears (5). Twenty-one of the 28 patients with 10-year FU had at least one late complication grades 1-4 and fourteen of them had more than one (2-5 each).

CONCLUSION

The most important result of our study is the relatively low proportion of severe late complications, comparable with other proton studies on various tumours. Furthermore, the numbers of late complications are lower than our own data set on a mixed population of photon and proton treated paediatric patients, assuring the safety of using proton therapy also in the clinical practice.

Association between conditioning intensity and height growth after allogeneic hematopoietic stem cell transplantation in children

BACKGROUND

The present study aimed to examine the association between the conditioning intensity and height growth in pediatric patients who underwent allogeneic hematopoietic stem cell transplantation (allo-HSCT).

METHODS

We reviewed the clinical records of 89 children with malignant diseases who underwent initial allo-HSCT between 2003 and 2021. Height measurements were standardized using standard height charts prepared by the Japanese Society for Pediatric Endocrinology to calculate standard deviation score (SDS). We defined short stature as a height SDS less than -2.0 in that reference. Myeloablative conditioning (MAC) comprised total-body irradiation at more than 8 Gy and busulfan administration at more than 8 mg/kg (more than 280 mg/m2 ). Other conditioning regimens were defined as reduced intensity conditioning (RIC).

RESULTS

A total of 58 patients underwent allo-HSCT with MAC, and 31 patients received allo-HSCT with RIC. There were significant differences in the height SDS at 2 and 3 years after allo-HSCT between MAC and RIC group (-1.33 ± 1.20 vs. -0.76 ± 1.12, p = 0.047, -1.55 ± 1.28 vs. -0.75 ± 1.11, p = 0.022, respectively). Multivariate logistic regression analysis with the adjustments for potential confounding factors of patients less than 10 years of age at allo-HSCT and chronic graft-versus host disease demonstrated that MAC regimen was associated with a markedly increased risk of a short stature at 3 years after allo-HSCT (adjusted odds ratio, 5.61; 95% confidence interval, 1.07-29.4; p = 0.041).

CONCLUSION

The intensity of conditioning regimen may be associated with short statures after allo-HSCT.

Longitudinal health-related quality of life analysis in childhood cancer survivors after proton beam therapy

PURPOSE

Whilst proton beam therapy (PBT) for children with cancer is expected to reduce their comorbidities, to date only a limited number of studies have been published. To analyze the long-term comorbidity and health-related quality of life (HRQoL) of childhood cancer survivors (CCSs) after PBT, we conducted a questionnaire-based study.

METHODS

Questionnaires were sent to CCSs who underwent PBT at the University of Tsukuba Hospital during the period from 1984 to 2020. Scores from 41 CCSs who did not undergo PBT (noPBT-CCSs) and from the general population were used for comparison.

RESULTS

In total, 110 individuals who underwent PBT participated in the study. Among them, 40 individuals were longitudinally analyzed. The range of change in the scores was significantly greater in the CCSs whose initial scores were low. Although the comorbidity levels were more severe, HRQoL tended to be better in the PBT-CCSs than in the noPBT-CCSs with central nervous system (CNS) or solid tumors, respectively. When compared with the general population, the psychosocial health summary scores and its components were not different in the noPBT-CNS-CCSs. On the other hand, the psychosocial health summary scores and/or at least one of the scores of emotional, social, and school functioning were significantly higher in the other CCSs groups.

CONCLUSIONS

The HRQoL scores of CCSs with low initial scores can be greatly changed over time. Appropriate psychosocial support for this population is warranted. PBT may avoid reduction in HRQoL in terms of the psychosocial functioning of CCSs with CNS tumors.

Predominant approaches in studies on health-related quality of life of young survivors of childhood or adolescent cancer: an integrative literature review

Abstract Survivors of childhood cancer constitute a growing population. The disease experienced, its treatment or the occurrence of late complications may affect survivors’ health-related quality of life (HRQOL). Understanding HRQOL is a challenge due to its conceptual complexity and the mode in which it is studied. Objective: To identify the predominant lines of research in the study of HRQOL in this population. Methods: An integrative literature review was carried out, involving a systematic search of primary articles indexed in the Scopus and PubMed databases. Results: In the 48 publications selected, four main lines of research were identified: HRQOL in survivors in general; HRQOL in long-term survivors; the study of determinants of HRQOL; and the study of methodological aspects of HRQOL measurement. A quantitative approach using generic measurement instruments predominates, and the conceptual model of HRQOL based on function emphasizes the importance of physical, psychological, and social functionality and the impact of the disease and treatment on these aspects. Conclusions: incorporating a qualitative, meaning-based approach to the understanding of lived experiences from a subjective and holistic perspective is indispensable.

Predominant approaches in studies on health-related quality of life of young survivors of childhood or adolescent cancer: an integrative literature review

Survivors of childhood cancer constitute a growing population. The disease experienced, its treatment or the occurrence of late complications may affect survivors' health-related quality of life (HRQOL). Understanding HRQOL is a challenge due to its conceptual complexity and the mode in which it is studied.

OBJECTIVE

To identify the predominant lines of research in the study of HRQOL in this population.

METHODS

An integrative literature review was carried out, involving a systematic search of primary articles indexed in the Scopus and PubMed databases.

RESULTS

In the 48 publications selected, four main lines of research were identified: HRQOL in survivors in general; HRQOL in long-term survivors; the study of determinants of HRQOL; and the study of methodological aspects of HRQOL measurement. A quantitative approach using generic measurement instruments predominates, and the conceptual model of HRQOL based on function emphasizes the importance of physical, psychological, and social functionality and the impact of the disease and treatment on these aspects.

CONCLUSIONS

incorporating a qualitative, meaning-based approach to the understanding of lived experiences from a subjective and holistic perspective is indispensable.

The Impact of Cancer-Related Fatigue on HRQOL in Survivors of Childhood Cancer: A DCCSS LATER Study

Simple Summary

Survivors of childhood cancer have an increased risk to experience symptoms of severe and persistent fatigue. We studied how fatigue might affect the health-related quality of life of these survivors. Questionnaire items asking about a broad range of daily life aspects were compared between fatigued survivors, survivors without fatigue and the general Dutch population. A total of eleven aspects were studied which were all negatively affected by fatigue, with the largest impact seen for Vitality (how much energy does a person have), General Health (perception of current and future health) and Role Limitations (work-related activities). Results show the negative impact fatigue can have on the daily lives of survivors and why it is important to treat fatigue adequately.

Abstract

Background: Early detection and management of late effects of treatment and their impact on health-related quality of life (HRQOL) has become a key goal of childhood cancer survivorship care. One of the most prevalent late effects is chronic fatigue (CF). The current study aimed to investigate the association between CF and HRQOL in a nationwide cohort of CCS. Methods: Participants were included from the Dutch Childhood Cancer Survivor Study (DCCSS) LATER cohort, a nationwide cohort of CCS. Participants completed the Checklist Individual Strength (CIS) to indicate CF (CIS fatigue severity subscale ≥ 35 and duration of symptoms ≥6 months) and the Short Form-36 (SF-36) and TNO (Netherlands Organization for Applied Scientific Research) and AZL (Leiden University Medical Centre) Adult’s Health-Related Quality of Life questionnaire (TAAQOL) as measures for HRQOL. Differences in mean HRQOL domain scores between CF and non-CF participants were investigated using independent samples t-tests and ANCOVA to adjust for age and sex. The association between CF and impaired HRQOL (scoring ≥ 2 SD below the population norm) was investigated using logistic regression analyses, adjusting for confounders. Results: A total of 1695 participants were included in the study. Mean HRQOL domain scores were significantly lower in participants with CF. In addition, CF was associated with impaired HRQOL on all of the domains (except physical functioning) with adjusted odds ratios ranging from 2.1 (95% CI 1.3–3.4; sexuality domain) to 30.4 (95% CI 16.4–56.2; vitality domain). Conclusions: CF is associated with impaired HRQOL, urging for the screening and regular monitoring of fatigue, and developing possible preventative programs and interventions.

Evaluation of volumetric modulated arc therapy (VMAT) - based total body irradiation (TBI) in pediatric patients

Background

The dosimetric characterization of volumetric modulated arc therapy (VMAT)-based total-body irradiation (TBI) in pediatric patients is evaluated.

Materials and methods

Twenty-two patients between the ages of 2 and 12 years were enrolled for VMAT-based TBI from 2018 to 2020. Three isocenters were irradiated over three overlapping arcs. While prescribing 90% of the TBI dose to the planning treatment volume (PTV), two fractions (2 Gy each) were delivered each day; hence 12 Gy was delivered in six fractions. During treatment optimization, the mean lung and kidney doses were set not to exceed 7 Gy and 7.5 Gy, respectively. The maximum lens dose was also set to less than 4 Gy. Patient quality assurance was carried out by comparing treatment planning system doses to the 3-dimensional measured doses by the ArcCHECK^® detector. The electronic portal imaging device (EPID) gamma indices were also obtained.

Results

The average mean lung dose was 7.75 ± 0.18 Gy, mean kidney dose 7.63 ± 0.26 Gy, maximum lens dose 4.41 ± 0.39 Gy, and the mean PTV dose 12.69 ± 0.16 Gy. The average PTV heterogeneity index was 1.15 ± 0.03. Average differences in mean kidney dose, mean lung dose, and mean target dose were 2.79% ± 0.88, 0.84% ± 0.45 and 0.93% ± 0.47, respectively; when comparing planned and ArcCHECK^® measured doses. Only grade 1-2 radiation toxicities were recorded, based on CTCAE v5.0 scoring criteria.

Conclusions

VMAT-TBI was characterized with good PTV coverage, homogeneous dose distribution, planned and measured dose agreement, and low toxicity.

Local Irradiation of Mouse Tooth Germ Gives Insight into the Direct Effects of Irradiation on Root Development

To elucidate the mechanism underlying the failure of root formation after irradiation, we established a method of local irradiation of the molar tooth germ and demonstrated that radiation directly affected dental root development. In the current study, to locally irradiate the lower first molars of 5-day-old C57BL/6J mice, we used lead glass containing a hole as a collimator. We confirmed that our local irradiation method targeted only the tooth germ. The irradiated root was immature in terms of apical growth, and dentin formation was irregular along the outside of the root apices. Moreover, calcified tissue apically surrounded Hertwig's epithelial root sheath, which disappeared abnormally early. This method using a local irradiation experimental model will facilitate research into radiation-induced disorders of dental root formation.

Neurocognitive impairment in Asian childhood cancer survivors: a systematic review

Childhood cancer survivors are at higher risk of developing neurocognitive deficits due to the intensive treatment they received at an early age. Most studies on childhood cancer survivorship have so far focused on the Western populations. Due to the ethnic, genetic, environmental, and cultural differences, clinical data of the Western populations may not be representative of Asian countries. This scoping review systematically summarized the existing clinical evidence of the neurocognitive impairment of Asian childhood cancer survivors. We searched the Embase and Medline databases for studies assessing the neurocognitive functions of survivors in Asia, who were diagnosed with cancer before the age of 19 and completed active treatment. The literature search identified 13 studies involving 2212 participants from five Asian countries: South Korea (n = 4, 30.8%), Taiwan (n = 3, 23.1%), Japan (n = 3, 23.1%), Hong Kong (n = 2, 15.4%), and Thailand (n = 1, 7.7%). The included studies focused on CNS tumors (n = 10, 76.9%), hematological malignancies (n = 7, 53.8%), or heterogeneous cancer diagnoses (n = 3, 23.1%). Collectively, mild-to-moderate impairment in intelligence was observed in 10.0 to 42.8% of survivors, which seemed higher than the reported rate in Western survivors. We speculate that the ethnic and genetic variations in drug responses and susceptibility to adverse chronic toxicities may have contributed to the differences in the prevalence and severity of neurocognitive impairment between these two populations. To better understand the effects of culturally relevant and region-specific environmental risk factors on the post-treatment neurocognitive development in cancer survivors, a holistic approach that addresses the complex interactions between biological, physical, and psychosocial factors is needed. This will aid the development of effective intervention strategies to improve the functional and psychosocial outcomes of cancer survivors in Asian societies.

Impacts of physical late effects on presenteeism in childhood cancer survivors

BACKGROUND

Many childhood cancer survivors (CCSs) experience physical late effects related to their cancer types and treatment modalities. Physical late effects are an important factor in various occupational outcomes among CCSs. However, the relationship between physical late effects and presenteeism has remained unclear. This study aimed to estimate the impacts of physical late effects on presenteeism among employed CCSs.

METHODS

Childhood cancer survivors replied to a questionnaire regarding presenteeism, and their attending physicians assessed their physical late effects between September 2014 and December 2015. The Work Limitations Questionnaire was used to measure presenteeism. Propensity score analysis and a generalized linear model were used to adjust covariates related to physical late effects and / or presenteeism.

RESULTS

Of the 125 questionnaires distributed, 114 were returned. The data from 61 employed CCSs were analyzed. After controlling for covariates by propensity score analysis and generalized linear model, there were no significant differences in presenteeism between employed CCSs with either no or single physical late effects. However, employed CCSs with multiple physical late effects reported higher scores in Output (Estimate = 9.3, P = 0.041), Physical Demands (Estimate = 12.2, P = 0.020), and Productivity Loss scores (Estimate = 2.4, P = 0.045) on the Work Limitations Questionnaire than employed CCSs with no physical late effects.

CONCLUSIONS

Employed CCSs with multiple physical late effects were at an increased risk for presenteeism. Healthcare and social welfare systems should be established to provide vocational assistance for CCSs after being employed to alleviate presenteeism.

Response to GH Treatment After Radiation Therapy Depends on Location of Irradiation

OBJECTIVES

Cancer survivors with GH deficiency (GHD) receive GH therapy (GHT) after 1+ year observation to ensure stable tumor status/resolution.

HYPOTHESIS

Radiation therapy (RT) to brain, spine, or extremities alters growth response to GHT.

AIM

Identify differences in growth response to GHT according to type/location of RT.

METHODS

The Pfizer International Growth Database was searched for cancer survivors on GHT for ≥5 years. Patient data, grouped by tumor type, were analyzed for therapy (surgery, chemotherapy, RT of the focal central nervous system, cranial, craniospinal, or total body irradiation [TBI] as part of bone marrow transplantation), sex, peak stimulated GH, age at GHT start, and duration from RT to GHT start. Kruskal-Wallis test and quantile regression modeling were performed.

RESULTS

Of 1149 GHD survivors on GHT for ≥5 years (male 733; median age 8.4 years; GH peak 2.8 ng/mL), 431 had craniopharyngioma (251, cranial RT), 224 medulloblastoma (craniospinal RT), 134 leukemia (72 TBI), and 360 other tumors. Median age differed by tumor group (P < 0.001). Five-year delta height SD score (SDS) (5-year ∆HtSDS; median [10th-90th percentile]) was greatest for craniopharyngioma, 1.6 (0.3-3.0); for medulloblastoma, 5-year ∆HtSDS 0.9 (0.0-1.9); for leukemia 5-year ∆HtSDS, after TBI (0.3, 0-0.7) versus without RT (0.5, 0-0.9), direct comparison P < 0.001. Adverse events included 40 treatment-related, but none unexpected.

CONCLUSIONS

TBI for leukemia had significant impact on growth response to GHT. Medulloblastoma survivors had intermediate GHT response, whereas craniopharyngioma cranial RT did not alter GHT response. Both craniospinal and epiphyseal irradiation negatively affect growth response to GH therapy compared with only cranial RT or no RT.

Height after photon craniospinal irradiation in pediatric patients treated for central nervous system embryonal tumors

BACKGROUND

We modeled height after craniospinal irradiation (CSI) in pediatric patients with central nervous system (CNS) embryonal tumors to identify factors that impair stature.

PROCEDURE

During 1996-2012, 212 pediatric patients (131 male) with CNS embryonal tumors received postoperative CSI: 23.4 Gy (n = 147) or ≥36 Gy (n = 65), similar postirradiation chemotherapy, and were followed for at least 5 years without tumor progression or other event. The group was further characterized by age at CSI and hormone-replacement therapy received. Models were developed to identify factors associated with growth impairment and estimate final height.

RESULTS

With median follow up of 10.2 years (range 5.0-20.4 years), the mean final height z-scores at 18 years of age, compared to United States standards, were -1.3 for female and -1.5 for male survivors. Younger age at the time of CSI, higher CSI dose, and female sex were associated with height impairment. Factors associated with higher growth rates before 15 years of age were older age at CSI, male sex, CSI dose < 36 Gy, replacement therapy for growth hormone (GH) and central adrenal insufficiency, and white race. Growth after age 15 in male survivors was associated with treatment of gonadotropin deficiency. Linear mixed-effects models were developed using clinical factors to estimate final height, demonstrate the unique growth curve of this cohort, and interactions between clinical variable and radiation dose.

CONCLUSIONS

CSI significantly impaired height at current doses used to treat standard- or high-risk CNS embryonal tumors. Measures to reduce the impact of CSI on height should be sought, with our models serving as benchmarks.

Evolving Radiotherapy Techniques in Paediatric Oncology

AIMS

Childhood cancer is rare and survival of childhood cancer has increased up to 80% at 5 years after diagnosis. Radiotherapy is an important element of the multimodal treatment concept. However, due to growing tissue, children are particularly sensitive to radiation-related side-effects and the induction of secondary malignancies. However, radiotherapy techniques have continuously progressed. In addition, modern treatment concepts have been improved in order to minimise long-term effects. Today, radiotherapy is used for various tumour types in childhood, such as sarcomas and tumours of the central nervous system.

MATERIALS AND METHODS

External beam therapy with either photons or protons and brachytherapy are predominantly used for the treatment of childhood tumours. Technical developments and features, as well as clinical outcomes, for several tumour entities are presented.

RESULTS

The development of radiotherapy techniques, as well as risk-adapted therapy concepts, resulted in promising outcome regarding tumour control, survival and therapy-related side-effects. It is assumed that proton therapy will be increasingly used for treating children in the future. However, more data have to be collected through multi-institutional registries in order to strengthen the evidence.

CONCLUSION

The development of radiotherapy techniques is beneficial for children in terms of reducing dose exposure. As compared with other modern and highly conformal techniques, particularly proton therapy may achieve high survival rates and tumour control rates while decreasing the risk for side-effects. However, clinical evidence for modern radiotherapy techniques is still limited today. An optimal patient triaging with the selection of the most appropriate radiation technique for each individual patient will be an important goal for the future.

Late endocrine effects of childhood cancer

The cure rate for paediatric malignancies is increasing, and most patients who have cancer during childhood survive and enter adulthood. Surveillance for late endocrine effects after childhood cancer is required to ensure early diagnosis and treatment and to optimize physical, cognitive and psychosocial health. The degree of risk of endocrine deficiency is related to the child's sex and their age at the time the tumour is diagnosed, as well as to tumour location and characteristics and the therapies used (surgery, chemotherapy or radiation therapy). Potential endocrine problems can include growth hormone deficiency, hypothyroidism (primary or central), adrenocorticotropin deficiency, hyperprolactinaemia, precocious puberty, hypogonadism (primary or central), altered fertility and/or sexual function, low BMD, the metabolic syndrome and hypothalamic obesity. Optimal endocrine care for survivors of childhood cancer should be delivered in a multidisciplinary setting, providing continuity from acute cancer treatment to long-term follow-up of late endocrine effects throughout the lifespan. Endocrine therapies are important to improve long-term quality of life for survivors of childhood cancer.

Cyclophosphamide-Induced Morphological Changes in Dental Root Development of ICR Mice

Background

Survivors of childhood cancer are at risk of late dental development. Cyclophosphamide is one of the most commonly used chemotherapeutic agents against cancer in children. The aim of this study was to investigate the effects of cyclophosphamide on root formation in the molars of growing mice and to assess the morphological changes in these roots using three-dimensional structural images.

Methods

We treated 16 12-day-old ICR mice with cyclophosphamide (100 mg/kg, i.p.) and 16 control mice with saline. At 16, 20, 24, and 27 days of age, the mandibular left first molars were scanned using soft micro-computed tomography. After scanning, the structural indices were calculated using a three-dimensional image analysis system, and the images were subjected to three-dimensional reconstruction. The length and apical foramen area of all distal roots were assessed. Histological changes in the apical region were then assessed via hematoxylin and eosin staining.

Results

The mandibular molars of all experimental mice showed evidence of cytotoxic injury, which appeared in the form of anomalous root shapes. Although all roots developed further after cyclophosphamide injection, the three-dimensional structural images showed that the roots in the experimental group tended to develop more slowly and were shorter than those in the control group. At 27 days of age, the mean root length was shorter in the experimental group than in the control group. Conversely, the apical foramen of the roots in the experimental group tended to close faster than that of roots in the control group. In addition, hematoxylin and eosin staining of the distal roots in the experimental group showed increased dentin thickness in the apical region.

Conclusion

Our results suggest that cyclophosphamide can result in short root lengths and early apical foramen closure, eventually leading to V-shaped or thin roots.

Advanced childhood testicular yolk sac tumor with bone metastasis: a case report

We report a case of advanced childhood testicular yolk sac tumor with bone metastasis, which was successfully treated by multimodal treatment. Optimal management of bone metastases from testicular yolk sac tumor in childhood is discussed.

Late toxicity of a novel allogeneic stem cell transplant using single fraction total body irradiation for hematologic malignancies in children

Single fraction total body irradiation (SFTBI) as part of a myeloablative preparative regimen in allogeneic hematopoietic stem cell transplantation (HSCT) for hematopoietic malignancies was shown to have similar survival compared with fractionated total body irradiation (FTBI)-containing regimens, with less acute toxicity. The objective of this study was to determine long-term toxicity >2 years following SFTBI-based HSCT. Twenty-one patients were evaluated at a median follow-up of 6.8 years. Thyroid dysfunction was found in 21% of patients, 1 of whom (5.2%) was symptomatic; 23% had gonadal failure; 50% of patients with growth potential had linear growth disturbance; 27% had mild to moderate pulmonary disease; and 25% had cataracts. Intelligence quotient was stable. cGVHD was present in 28%, and 4 patients (19%) were on immune suppression 2 years posttransplant. Overall survival subsequent to 2 years posttransplant was 76% in this cohort of patients. No secondary malignancies were observed. In conclusion, the toxicities of SFTBI occurred at similar or reduced frequency compared with FTBI. SFTBI should be considered for patients who may benefit from a radiation-containing HSCT preparative regimen.

Proton radiotherapy for pediatric tumors: review of first clinical results

Radiation therapy is a part of multidisciplinary management of several childhood cancers. Proton therapy is a new method of irradiation, which uses protons instead of photons. Proton radiation has been used safely and effectively for medulloblastoma, primitive neuro-ectodermal tumors, craniopharyngioma, ependymoma, germ cell intracranial tumors, low-grade glioma, retinoblastoma, rhabdomyosarcoma and other soft tissue sarcomas, Ewing’s sarcoma and other bone sarcomas. Moreover, other possible applications are emerging, in particular for lymphoma and neuroblastoma. Although both photon and proton techniques allow similar target volume coverage, the main advantage of proton radiation therapy is to sparing of intermediate-to-low-dose to healthy tissues. This characteristic could translate into clinical reduction of side effects, including a lower risk for secondary cancers. The following review presents the state of the art of proton therapy in the treatment of pediatric malignancies.

Development of the Japanese version of the Minneapolis-Manchester Quality of Life Survey of Health - Adolescent Form (MMQL-AF) and investigation of its reliability and validity

Background

There are very few reliable and valid measures in Japan assessing health-related quality of life (HRQOL) in children with cancer. The present study aimed to develop a Japanese version of the Minneapolis-Manchester Quality of Life Survey of Health Adolescent Form (MMQL-AF), which is a measure for assessing the HRQOL of childhood cancer survivors, and investigate its reliability and validity.

Methods

Participants were 141 children with cancer who had been off therapy for more than one year and 183 healthy controls. The reliability and internal consistency of the measure were assessed through test-retest methods using Cronbach’s coefficient alpha and intra-class correlation coefficients (ICCs). For validation of the measure, factorial validity, concurrent validity using the Japanese version of PedsQL 4.0 Generic Core Scales (PedsQL-J), and discriminant validity using comparisons between children with cancer and healthy controls were investigated.

Results

Of the 46 items in the original version, 44 items were determined to comprise the Japanese version of the MMQL-AF. Cronbach’s coefficient alphas for each subscale were high ranging from 0.83 to 0.89. Test-retest reliability ranged between ICC 0.79 to 0.96. Investigation of concurrent validity using the PedsQL-J demonstrated strong correlations in physical functions and moderate correlations for other factors. A significant difference was observed between children with cancer and healthy controls.

Conclusions

Thus, the Japanese version of the MMQL-AF served as a self-evaluation questionnaire that allowed for practical, comprehensive, and multidimensional measurement of HRQOL specific to childhood cancer survivors.

FANCD2 is a potential therapeutic target and biomarker in alveolar rhabdomyosarcoma harboring the PAX3-FOXO1 fusion gene

PURPOSE

Alveolar rhabdomyosarcoma that harbors the PAX3-FOXO1 fusion gene (t-ARMS) is a common and lethal subtype of this childhood malignancy. Improvement in clinical outcomes in this disease is predicated upon the identification of novel therapeutic targets.

EXPERIMENTAL DESIGN

Robust mouse models were used for in vivo analysis, and molecular studies were performed on xenografts treated in parallel. Two independent patient sets (n = 101 and 124) of clinically annotated tumor specimens were used for analysis of FANCD2 levels and its association with clinical and molecular characteristics and outcomes.

RESULTS

Our xenograft studies reveal a selective suppression of FANCD2 by m-TOR kinase inhibition and radiosensitization of the t-ARMS line only. In the initial patient set, we show that FANCD2 transcript levels are prognostic in univariate analysis, and are significantly associated with metastatic disease and that the copresence of the translocation and high expression of FANCD2 is independently prognostic. We also demonstrate a significant and nonrandom enrichment of mTOR-associated genes that correlate with FANCD2 gene expression within the t-ARMS samples, but not within other cases. In the second patient set, we show that on a protein level, FANCD2 expression correlates with PAX3-FOXO1 fusion gene and is strongly associated with phospho-P70S6K expression in cases with the fusion gene.

CONCLUSIONS

Our data demonstrate that FANCD2 may have a significant role in the radiation resistance and virulence of t-ARMS. Indirectly targeting this DNA repair protein, through mTOR inhibition, may represent a novel and selective treatment strategy.

The application of radiation therapy to the Pediatric Preclinical Testing Program (PPTP): results of a pilot study in rhabdomyosarcoma

BACKGROUND

The Pediatric Preclinical Testing Program (PPTP) has been successfully used to determine the efficacy of novel agents against solid tumors by testing them within a mouse-flank in vivo model. To date, radiation therapy has not been applied to this system. We report on the feasibility and biologic outcomes of a pilot study using alveolar and embryonal rhabdomyosarcoma xenograft lines.

PROCEDURES

We developed a high-throughput mouse-flank irradiation device that allows the safe delivery of radiotherapy in clinically relevant doses. For our pilot study, two rhabdomyosarcoma xenograft lines from the PPTP, Rh30 (alveolar) and Rh18 (embryonal) were selected. Using established methods, xenografts were implanted, grown to appropriate volumes, and were subjected to fractionated radiotherapy. Tumor response-rates, growth kinetics, and event-free survival time were measured.

RESULTS

Once optimized, the rate of acute toxicity requiring early removal from study in 93 mice was only 3%. During the optimization phase, it was observed that the alveolar Rh30 xenograft line demonstrated a significantly greater radiation resistance than embryonal Rh18 in vivo. This finding was validated within the standardized 30 Gy treatment phase, resulting in overall treatment failure rates of 10% versus 60% for the embryonal versus alveolar subtype, respectively.

CONCLUSIONS

Our pilot study demonstrated the feasibility of our device which enables safe, clinically relevant focal radiation delivery to immunocompromised mice. It further recapitulated the expected clinical radiobiology.

Decreased serum testosterone levels in long-term adult survivors with fatty liver after childhood stem cell transplantation

Fatty liver and male gonadal dysfunction are potential late effects of therapy in adult survivors treated with stem cell transplantation (SCT) in childhood. Obesity and metabolic syndrome also are associated with low serum testosterone levels in the general population. However, the relationship between the degree of fatty liver and changes in serum testosterone levels in adult survivors has not been fully studied. We reviewed the clinical records of 34 male patients who received allogeneic SCT in childhood or adolescence. The median age at SCT was 10.0 years, and the median follow-up after SCT was 15.9 years. All but one patient showed no tendency toward overweight/obesity during the follow-up period. Fatty liver was diagnosed by ultrasound in 15 patients at 4 to 20 years after SCT. Patients who received cranial radiation therapy before SCT were more likely to develop fatty liver and insulin resistance. Moreover, fatty liver was statistically associated with decreased serum testosterone levels, whereas nonfatty liver was not (median, 527 ng/dL [range, 168-944 ng/dL] versus 302 ng/dL [165-698 ng/dL]; P < .0001). Changes in testosterone levels after SCT are affected not only by primary gonadal dysfunction but also by subsequent development or exacerbation of fatty liver.

Head-to-head comparisons of quality of life instruments for young adult survivors of childhood cancer

PURPOSE

Few studies examine the relevance of health-related quality of life (HRQOL) instruments for young adult survivors of childhood cancer (YASCC). This study compared the psychometric properties of two survivor-specific instruments, the Quality of Life-Cancer Survivor (QOL-CS) and Quality of Life in Adult Cancer Survivor (QLACS).

METHODS

Data from 151 YASCC who enrolled in cancer/tumor registries of two medical centers were used. We examined construct validity by conducting confirmatory factor analysis using indices of chi-square statistic, comparative fit index, and root mean square error of approximation. We examined convergent/discriminant validity by comparing Pearson's correlation coefficients of homogeneous (e.g., physical functioning and pain) of both instruments versus heterogeneous domains (e.g., physical and psychological functioning). We assessed known-groups validity by examining the extent to which HRQOL differed by late effects and comorbid conditions and calculated relative validity (RV) defined as contrasting F-statistics of individual domains to the domain with the lowest F-statistic. Superior known-groups validity is observed if a domain of one instrument demonstrates a higher RV than other domains of the instruments.

RESULTS

YASCC data cannot replicate the constructs both instruments intend to measure, suggesting poor construct validity. Correlations of between-homogeneous and between-heterogeneous domains of both instruments were not discernible, suggesting poor convergent/discriminant validity. Both instruments were equally able to differentiate HRQOL between YASCC with and without late effects and comorbid conditions, suggesting similar known-groups validity.

CONCLUSIONS

Neither instrument is superior. Item response theory is suggested to select high-quality items from different instruments to improve HRQOL measure for YASCC.

Using three legacy measures to develop a health-related quality of life tool for young adult survivors of childhood cancer

BACKGROUND

Little attention has been paid to selecting and developing health-related quality of life (HRQOL) measurement tools for young adult survivors of childhood cancer (YASCC). The primary purpose of this study was to develop a HRQOL tool for YASCC based on three legacy instruments.

METHODS

Data collected from 151 YASCC were analyzed. HRQOL was measured using the Medical Outcomes Study SF-36, Quality of Life in Adult Cancer Survivors, and Quality of Life-Cancer Survivor. We used the following stages to develop our HRQOL tool: mapping items from three instruments into a common HRQOL construct, checking dimensionality using confirmatory factor analyses (CFA), and equating items using Rasch modeling.

RESULTS

We assigned 123 items to a HRQOL construct comprised of six generic and eight survivor-specific domains. CFA retained 107 items that meet the assumptions of unidimensionality and local independence. Rasch analysis retained 68 items that satisfied the indices of information-weighted/outlier-sensitive fit statistic mean square. However, items in most domains possess relatively easy measurement properties, whereas YASCC's underlying HRQOL was on the middle to higher levels.

CONCLUSIONS

Psychometric properties of the established tool for measuring HRQOL of YASCC were not satisfied. Future studies need to refine this tool, especially adding more challenging items.

Social outcomes and quality of life of childhood cancer survivors in Japan: a cross-sectional study on marriage, education, employment and health-related QOL (SF-36)

Social outcomes and quality of life (QOL) of childhood cancer survivors (CCSs) remain unknown in Japan. We investigated these outcomes in young adult CCSs compared to those of their siblings in Japan, and analyzed the association between social outcome and SF-36 health survey subscale scores. Between 2007 and 2009, we performed a cross-sectional survey using self-rating questionnaires. We estimated social outcomes and health-related QOL by performing the SF-36 in each group: CCSs with or without stem cell transplantation (SCT)/radiotherapy (RT) and their siblings. Adjusted odds ratios for outcomes of interest were estimated using logistic regression analysis. Questionnaires from 185 CCSs and 72 CCS's siblings were analyzed. There were no differences in educational attainment or annual income. The SF-36 subscale scores of CCSs with SCT and RT were significantly lower than those of siblings in physical functioning (PF) (p < 0.001 and 0.003, respectively) and general health (GH) (both p = 0.001). Lower PF scores correlated with recurrence (p = 0.041) and late effects (p = 0.010), and poor GH scores with late effects (p = 0.006). The CCSs had made efforts to attain educational/vocational goals; however, a significant proportion of CCSs who had experienced late effects remain at increased risk of experiencing diminished QOL.