Risk Factors for Small Adult Height in Childhood Cancer Survivors

Radiation Doses Received by Major Organs at Risk in Children and Young Adolescents Treated for Cancer with External Beam Radiation Therapy: A Large-scale Study from 12 European Countries

PURPOSE

Childhood cancer survivors, in particular those treated with radiation therapy, are at high risk of long-term iatrogenic events. The prediction of risk of such events is mainly based on the knowledge of the radiation dose received to healthy organs and tissues during treatment of childhood cancer diagnosed decades ago. We aimed to set up a standardized organ dose table to help former patients and clinicians in charge of long-term follow-up clinics.

METHODS AND MATERIALS

We performed whole body dosimetric reconstruction for 2646 patients from 12 European countries treated between 1941 and 2006 (median, 1976). Most plannings were 2- or 3-dimensional. A total of 46% of patients were treated using Cobalt 60, and 41%, using a linear accelerator. The median prescribed dose was 27.2 Gy (IQ1-IQ3, 17.6-40.0 Gy). A patient-specific voxel-based anthropomorphic phantom with more than 200 anatomic structures or substructures delineated as a surrogate of each subject's anatomy was used. The radiation therapy was simulated with a treatment planning system based on available treatment information. The radiation dose received by any organ of the body was estimated by extending the treatment planning system dose calculation to the whole body, by type and localization of childhood cancer.

RESULTS

The integral dose and normal tissue doses to most of the 23 considered organs increased between the 1950s and 1970s and decreased or plateaued thereafter. Whatever the organ considered, the type of childhood cancer explained most of the variability in organ dose. The country of treatment explained only a small part of the variability.

CONCLUSIONS

The detailed dose estimates provide very useful information for former patients or clinicians who have only limited knowledge about radiation therapy protocols or techniques, but who know the type and site of childhood cancer, sex, age, and year of treatment. This will allow better prediction of the long-term risk of iatrogenic events and better referral to long-term follow-up clinics.

Impact of Childhood Cancer on Growth

Along with improvements in cancer treatment over time, the number of childhood cancer survivors has been growing. Survivors are at risk for serious medical complications, and growth impairment is among the most common. There are multiple factors that may cause impaired growth among survivors. In this article, we review the impact of cancer on growth in children and adolescents. We first provide an overview of growth disturbance among childhood cancer patients and survivors due to nonhormonal causes, including a recent understanding of the effect of targeted cancer therapies (eg, tyrosine kinase inhibitors and immune checkpoint inhibitors) on growth. Then we describe the hormonal causes of growth impairment among survivors, focusing on growth hormone deficiency, including the prevalence, risk factors, and treatment. Lastly, we briefly summarize overgrowth and tall stature in childhood cancer. It is critical to assess the linear growth of children and adolescents, especially in cancer survivors who are at risk for growth disturbance, since growth is an important measure of their health.

Advantages and limitations of estrogen replacement therapy on hypogonadal survivors of childhood cancer

BACKGROUND

Hypogonadism is a significant late complication in childhood cancer survivors (CCS). The aim of this study was to elucidate the advantages and limitations of estrogen replacement therapy (ERT) for CCS with hypogonadism.

METHODS

Seventeen CCS were divided into two groups: gonadal hypogonadism (GH) group (n = 8) and central hypogonadism (CH) group (n = 9). Pearson correlation coefficients were used to investigate the impact of cancer management on final height, bone density, and uterine development.

RESULTS

Seven of GH group had hematologic malignancies, and all of them underwent total body irradiation before bone marrow transplantation. The GH group showed significant positive correlations between the onset age of disease treatment and final height (p < 0.05, R = 0.712) and uterine size following ERT (p < 0.05, R = 0.775). All CCS in the CH group had brain tumors, and seven of them received chemotherapy. There were trends towards positive and negative correlations between the onset age of disease treatment and final height (p = 0.09, R = 0.598) or uterine size (p = 0.07, R = - 0.669), respectively. A negative correlation trend was observed between the age at ERT initiation and final height (p = 0.07, R = - 0.769) or bone density (p = 0.18, R = - 0.626) in six CH patients who received growth hormone therapy. Five CCS in both groups experienced osteoporosis, despite receiving ERT.

CONCLUSION

Individualized management strategies beyond ERT are essential to reduce long-term complications in CCS with hypogonadism, considering the type and timing of cancer treatment.

Surveillance after childhood cancer: are survivors with an increased risk for cardiomyopathy regularly followed-up?

BACKGROUND

We aimed to study adherence to cardiac screening in long-term childhood cancer survivors (CCS) at high risk of cardiomyopathy.

METHODS

This study involved 976 5-year CCS at high risk for cardiomyopathy from the French Childhood Cancer Survivor Study. Determinants of adherence to recommended surveillance were studied using multivariable logistic regression models. Association of attendance to a long-term follow-up (LTFU) visit with completion of an echocardiogram was estimated using a Cox regression model.

RESULTS

Among participants, 32% had an echocardiogram within the 5 previous years. Males (adjusted RR [aRR] 0.71, 95% CI 0.58-0.86), survivors aged 36-49 (aRR 0.79, 95% CI 0.64-0.98), Neuroblastoma (aRR 0.53, 95% CI 0.30-0.91) and CNS tumour survivors (aRR 0.43, 95% CI 0.21-0.89) were less likely to adhere to recommended surveillance. Attendance to an LTFU visit was associated with completion of an echocardiogram in patients who were not previously adherent to recommendations (HR 8.20, 95% CI 5.64-11.93).

CONCLUSIONS

The majority of long-term survivors at high risk of cardiomyopathy did not adhere to the recommended surveillance. Attendance to an LTFU visit greatly enhanced the completion of echocardiograms, but further interventions need to be developed to reach more survivors.

Cohort profile: Risk and risk factors for female breast cancer after treatment for childhood and adolescent cancer: an internationally pooled cohort

PURPOSE

The International Consortium for Pooled Studies on Subsequent Malignancies after Childhood and Adolescent Cancer was established in 2018 to address gaps in knowledge of risk and risk factors for breast cancer subsequent to childhood/adolescent cancer by pooling individual patient data from seven cohorts. Initially, the pooled cohort will focus on three clinically relevant questions regarding treatment-related subsequent breast cancer risk in female survivors, which are the risk related to low-dose radiotherapy exposure to the chest, specific chemotherapy agents and attained age.

PARTICIPANTS

The consortium database includes pooled data on 21 892 female survivors from seven cohorts in North America and Europe with a primary cancer diagnosis at <21 years of age, and survival ≥5 years from diagnosis.

FINDINGS TO DATE

This is a newly established pooled study. The cohort profile summarised the data collected from each included cohort, including childhood cancer diagnosis information and treatment details (ie, radiotherapy fields and cumulative doses, and chemotherapy agents and cumulative doses for each agent). Included cohorts' follow-up started 1951-1981 and ended 2013-2021, respectively, for a median follow-up duration of 24.3 (IQR 18.0-32.8) years since primary cancer diagnosis. The median age at primary cancer diagnosis was 5.4 (IQR 2.5-11.9) years. And the median attained age at last follow-up was 32.2 (IQR 24.0-40.4) years. In all, 4240 (19.4%) survivors were treated with radiotherapy to the chest and 9308 (42.5%) with anthracyclines. At the end of the follow-up, 835 females developed a first subsequent breast cancer, including 635 invasive breast cancer only, 184 carcinomas in situ only (172 ductal carcinomas in situ and 12 lobular carcinomas in situ), and 16 with both an invasive and in situ diagnosis at the same moment. The cumulative incidences of subsequent breast cancer (both invasive and in situ) 25 and 35 years after primary cancer diagnosis were 2.2% and 6.2%, respectively.

FUTURE PLANS

The consortium is intended to serve as a model and robust source of childhood/adolescent cancer survivor data for elucidating other knowledge gaps on subsequent breast cancer risk, and risk of other subsequent malignancies (including data on males) in the future.

Growth and Nutritional Outcomes in Children Post-Haematopoietic Stem Cell Transplant without Exposure to Total Body Irradiation

AIMS

Poor growth in childhood cancer survivors who undergo haematopoietic stem cell transplant (HSCT) without exposure to radiation is reported anecdotally, although literature to support this is limited. The aims of this study were to assess the change in height standard deviation score (SDS) and the final adult height (FAH) in children who underwent chemotherapy-only conditioned HSCT and to identify predictors of poor growth.

MATERIALS AND METHODS

We conducted a retrospective hospital medical record review (1984-2010) of children (1-10 years) who underwent chemotherapy-only conditioned HSCT, noting anthropology measurements at cancer diagnosis, HSCT, 10 years old and FAH.

RESULTS

The median age at HSCT of the 53 patients was 4.5 years, 75% had a haematological malignancy and 25% a solid tumour. Half of the cohort underwent allogenic HSCT and most (89%) conditioned with busulphan. The mean change in height SDS from primary cancer diagnosis to FAH was -1.21 (±1.18 SD), equivalent to 7-8.5 cm loss, with a mean FAH of -0.91 SDS (±1.10 SD). The greatest height loss occurred between diagnosis and HSCT (-0.77 SDS, 95% confidence interval -1.42, -0.12, P = 0.01), with no catch-up growth seen by FAH. Patients with solid tumours had the greatest height loss. Overall body mass index SDS did not change significantly over time, or by cancer type.

CONCLUSIONS

Chemotherapy-only conditioned HSCT during childhood can impact FAH, with the greatest height loss occurring prior to HSCT and no catch-up growth after treatment finishes. Children transplanted for a solid tumour malignancy seem to be more at risk, possibly due to intensive treatment regimens, both pre-transplant and during conditioning.

Safety of growth hormone (GH) treatment in GH deficient children and adults treated for cancer and non-malignant intracranial tumors-a review of research and clinical practice

Individuals surviving cancer and brain tumors may experience growth hormone (GH) deficiency as a result of tumor growth, surgical resection and/or radiotherapy involving the hypothalamic-pituitary region. Given the pro-mitogenic and anti-apoptotic properties of GH and insulin-like growth factor-I, the safety of GH replacement in this population has raised hypothetical safety concerns that have been debated for decades. Data from multicenter studies with extended follow-up have generally not found significant associations between GH replacement and cancer recurrence or mortality from cancer among childhood cancer survivors. Potential associations with secondary neoplasms, especially solid tumors, have been reported, although this risk appears to decline with longer follow-up. Data from survivors of pediatric or adult cancers who are treated with GH during adulthood are scarce, and the risk versus benefit profile of GH replacement of this population remains unclear. Studies pertaining to the safety of GH replacement in individuals treated for nonmalignant brain tumors, including craniopharyngioma and non-functioning pituitary adenoma, have generally been reassuring with regards to the risk of tumor recurrence. The present review offers a summary of the most current medical literature regarding GH treatment of patients who have survived cancer and brain tumors, with the emphasis on areas where active research is required and where consensus on clinical practice is lacking.

Long-term follow-up of high-risk neuroblastoma survivors treated with high-dose chemotherapy and stem cell transplantation rescue

Intensive treatments including high-dose chemotherapy (HDC) with autologous stem cell rescue have improved high-risk neuroblastoma (HRNB) survival. We report the long-term health status of 145 HRNB survivors, alive and disease-free 5 years post HDC. Median follow-up was 15 years (range = 5-34). Six patients experienced late relapses, 11 developed second malignant neoplasms (SMNs), and 9 died. Event-free and overall survivals 20 years post HDC were 82% (95% CI = 70%-90%) and 89% (78%-95%), respectively. Compared with the French general population, the standardized mortality ratio was 19 (95% CI = 8.7-36.1; p < 0.0001) and the absolute excess risk was 37.6 (19.2-73.5). Late effects were observed in 135/145 patients (median = 3 events/patient); 103 had at least one severe event. SMNs arose at a median of 20 years post HDC and included carcinoma (n = 5), sarcoma (2), acute myeloid leukemia (2), melanoma (1), and malignant glioma (1). Non-oncologic health events included dental maldevelopment (60%), severe hearing loss (20% cumulative probability at 15 years), hepatic focal nodular hyperplasia (14%), thyroid (11%), cardiac (8%), and renal (7%) diseases and growth retardation (height-for-age z-score ≤ -2 for 21%). Gonadal insufficiency was near-universal after busulfan (40/43 females, 33/35 males). Severe late effects are frequent and progressive in HRNB survivors needing systematic very long-term follow-up.

Late Effects in Childhood Cancer Survivors: Early Studies, Survivor Cohorts, and Significant Contributions to the Field of Late Effects

With improvement in cure of childhood cancer came the responsibility to investigate the long-term morbidity and mortality associated with the treatments accountable for this increase in survival. Several large cohorts of childhood cancer survivors have been established throughout Europe and North America to facilitate research on long-term complications of cancer treatment. The cohorts have made significant contributions to the understanding of early mortality, somatic late complications, and psychosocial outcomes among childhood cancer survivors, which has been translated into the design of new treatment protocols for pediatric cancers, with the goal to reduce the potential risk and severity of late effects.

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.

Identifying clusters of health risk behaviors and their predictors in adult survivors of childhood cancer: A report from the French Childhood Cancer Survivor Study

OBJECTIVE

Health risk behaviors (HRB) of childhood cancer survivors (CCS) are generally studied separately, despite the evidence suggesting that HRB are not independent. To our knowledge, few studies have examined HRB profiles in the former pediatric cancer patients. In this study, we identified HRB profiles and examined predictors engaging in unhealthy behaviors in CCS.

METHODS

We used data from a French cohort of CCS that includes five-year survivors diagnosed between 1945 and 2000 and treated before reaching age 18, in five centers in France. A total of 2961 adult CCS answered a self-reported questionnaire pertaining to HRB. Latent class analysis was used to identify HRB profiles combining physical activity, smoking, cannabis use, and alcohol drinking. Multinomial logistic analyses examined predictors for engaging in unhealthy behaviors.

RESULTS

Three HRB patterns emerged: "Low-risk" (n = 1846, 62.3%) included CCS who exhibited the highest frequency for usual physical activity and the lowest probabilities for current smoking or cannabis use, but most drank at least moderately; "Moderate-risk behaviors" (n = 291, 9.8%), and "High-risk behaviors" (n = 824, 27.8%) for CCS who exhibited the highest frequencies for current smoking, cannabis use, and heavy drinking. The multivariable regression revealed that male CCS, less educated or not married were significantly more likely to be in the high-risk behaviors group than the low-risk group.

CONCLUSIONS

As CCS remain a vulnerable population, screening for HRB should be routinized in long-term follow-up care and interventions targeting multiple HRB simultaneously among survivors should be developed.