Risk of subsequent gliomas and meningiomas among 69,460 5-year survivors of childhood and adolescent cancer in Europe: the PanCareSurFup study

BACKGROUND

Childhood cancer survivors are at risk of subsequent gliomas and meningiomas, but the risks beyond age 40 years are uncertain. We quantified these risks in the largest ever cohort.

METHODS

Using data from 69,460 5-year childhood cancer survivors (diagnosed 1940-2008), across Europe, standardized incidence ratios (SIRs) and cumulative incidence were calculated.

RESULTS

In total, 279 glioma and 761 meningioma were identified. CNS tumour (SIR: 16.2, 95% CI: 13.7, 19.2) and leukaemia (SIR: 11.2, 95% CI: 8.8, 14.2) survivors were at greatest risk of glioma. The SIR for CNS tumour survivors was still 4.3-fold after age 50 (95% CI: 1.9, 9.6), and for leukaemia survivors still 10.2-fold after age 40 (95% CI: 4.9, 21.4). Following cranial radiotherapy (CRT), the cumulative incidence of a glioma in CNS tumour survivors was 2.7%, 3.7% and 5.0% by ages 40, 50 and 60, respectively, whilst for leukaemia this was 1.2% and 1.7% by ages 40 and 50. The cumulative incidence of a meningioma after CRT in CNS tumour survivors doubled from 5.9% to 12.5% between ages 40 and 60, and in leukaemia survivors increased from 5.8% to 10.2% between ages 40 and 50.

DISCUSSION

Clinicians following up survivors should be aware that the substantial risks of meningioma and glioma following CRT are sustained beyond age 40 and be vigilant for symptoms.

Cumulative Absolute Risk of Subsequent Colorectal Cancer After Abdominopelvic Radiotherapy Among Childhood Cancer Survivors: A PanCareSurFup Study

PURPOSE

Childhood cancer survivors are at the risk of developing subsequent colorectal cancers (CRCs), but the absolute risks by treatment modality are uncertain. We quantified the absolute risks by radiotherapy treatment characteristics using clinically accessible data from a Pan-European wide case-control study nested within a large cohort of childhood cancer survivors: the PanCareSurFup Study.

METHODS

Odds ratios (ORs) from a case-control study comprising 143 CRC cases and 143 controls nested within a cohort of 69,460 survivors were calculated. These, together with standardized incidence ratios for CRC for this cohort and European general population CRC incidence rates and survivors' mortality rates, were used to estimate cumulative absolute risks (CARs) by attained age for different categories of radiation to the abdominopelvic area.

RESULTS

Overall, survivors treated with abdominopelvic radiotherapy treatment (ART) were three times more likely to develop a subsequent CRC than those who did not receive ART (OR, 3.1 [95% CI, 1.4 to 6.6]). For male survivors treated with ART, the CAR was 0.27% (95% CI, 0.17 to 0.59) by age 40 years, 1.08% (95% CI, 0.69 to 2.34) by age 50 years (0.27% expected in the general population), and 3.7% (95% CI, 2.36 to 7.80) by age 60 years (0.95% expected). For female survivors treated with ART, the CAR was 0.29% (95% CI, 0.18 to 0.62) by age 40 years, 1.03% (95% CI, 0.65 to 2.22) by age 50 years (0.27% expected), and 3.0% (95% CI, 1.91 to 6.37) by age 60 years (0.82% expected).

CONCLUSION

We demonstrated that by age 40 years survivors of childhood cancer treated with ART already have a similar risk of CRC as those age 50 years in the general population for whom population-based CRC screening begins in many countries. This information should be used in the development of survivorship guidelines for the risk stratification of survivors concerning CRC risk.

Employment, occupation, and income in adults with neurofibromatosis 1 in Denmark: a population- and register-based cohort study

BACKGROUND

Little is known about employment status, occupation, and disposable income in adults with NF1.

METHODS

From the Danish National Patient Registry and database of two national Centers for Rare Diseases, we identified 1469 adults with NF1, who were matched to 11,991 randomly selected population comparisons on sex and birth year and month. Annual information on employment, occupation and disposable income was ascertained from national registries in 1980-2019.

RESULTS

Adults with NF1 had a lower odds ratio (OR) for employment [OR 0.71, 95% confidence interval (CI) 0.61-0.83] and higher OR for health-related unemployment (OR 2.94, 95% CI 2.16-3.96) at age 30 years than population comparisons, which persisted at age 40 and 50 years. Somatic diagnoses were associated with a higher OR for health-related unemployment in adults with NF1 than in the population comparisons. Adults with NF1 had a slightly lower disposable income, with a 14% (0.82-0.89) reduction observed among the youngest birth cohort. Furthermore, adults with NF1 were less likely to be in a high skilled occupation at ages 30, 40 and 50 years.

CONCLUSION

Adults with NF1 have a lower employment rate, which was mainly due to health-related reasons and a slightly lower disposable income than adults without NF1. Thus, anticipation guidance for employment should be part of the management of NF1 families.

Endocrine morbidity in neurofibromatosis 1: a nationwide, register-based cohort study

OBJECTIVE

Previous studies have found that neurofibromatosis 1 (NF1) is associated with an increased risk for endocrine disorders, but no comprehensive overview of the risk for specific endocrine disorders has been published. We assessed endocrine morbidity in individuals with NF1 from information on hospital admissions, surgery for endocrine disorders, and relevant medication.

DESIGN

A nationwide population registry-based cohort study.

METHODS

We identified 2467 individuals with NF1 diagnosed between 1977 and 2013 from the Danish National Patient Register and the RAREDIS database and 20 132 randomly sampled age- and sex-matched population comparisons. Information on endocrine diseases was identified using registrations of discharge diagnoses, surgery, and medication prescriptions. The rates of endocrine disorders in individuals with NF1 were compared with those in the comparison cohort in Cox proportional hazard models.

RESULTS

Individuals with NF1 had a higher rate than the comparison group of any endocrine discharge diagnosis (hazard ratio [HR] 1.72, 95% confidence interval [CI]: 1.58-1.87), endocrine-related surgery (2.03, 1.39-2.96), and prescribed medications (1.32, 1.23-1.42). Increased HRs were observed for diseases and surgical operations of several glands, including pheochromocytoma, and for osteoporosis, and osteoporotic fractures. Decreased rates were observed with drugs for type 2 diabetes. Women with NF1 had higher HRs for surgery of the ovaries, uterus, and sterilization, but lower rates of surgeries of cervix and prescriptions for birth control pills.

CONCLUSIONS

Neurofibromatosis 1 is associated with a variety of endocrine disorders, surgery, and medication related to endocrine disease. Awareness of endocrine morbidity is important in the clinical follow-up of individuals with NF1.

Risk Factors for Primary Bone Cancer After Childhood Cancer: A PanCare Childhood and Adolescent Cancer Survivor Care and Follow-Up Studies Nested Case-Control Study

PURPOSE

Radiation to the bone and exposure to alkylating agents increases the risk of bone cancer among survivors of childhood cancer, but there is uncertainty regarding the risks of bone tissue radiation doses below 10 Gy and the dose-response relationship for specific types of chemotherapy.

METHODS

Twelve European countries contributed 228 cases and 228 matched controls to a nested case-control study within a cohort of 69,460 5-year survivors of childhood cancer. Odds ratios (ORs) of developing bone cancer for different levels of cumulative radiation exposure and cumulative doses of specific types of chemotherapy were calculated. Excess ORs were calculated to investigate the shape and extent of any dose-response relationship.

RESULTS

The OR associated with bone tissue exposed to 1-4 Gy was 4.8-fold (95% CI, 1.2 to 19.6) and to 5-9 Gy was 9.6-fold (95% CI, 2.4 to 37.4) compared with unexposed bone tissue. The OR increased linearly with increasing dose of radiation (Ptrend < .001) up to 78-fold (95% CI, 9.2 to 669.9) for doses of ≥40 Gy. For cumulative alkylating agent doses of 10,000-19,999 and ≥20,000 mg/m2, the radiation-adjusted ORs were 7.1 (95% CI, 2.2 to 22.8) and 8.3 (95% CI, 2.8 to 24.4), respectively, with independent contributions from each of procarbazine, ifosfamide, and cyclophosphamide. Other cytotoxics were not associated with bone cancer.

CONCLUSION

To our knowledge, we demonstrate-for the first time-that the risk of bone cancer is increased 5- to 10-fold after exposure of bone tissue to cumulative radiation doses of 1-9 Gy. Alkylating agents exceeding 10,000 mg/m2 increase the risk 7- to 8-fold, particularly following procarbazine, ifosfamide, and cyclophosphamide. These substantially elevated risks should be used to develop/update clinical follow-up guidelines and survivorship care plans.

Perceived barriers and facilitators to health behaviors in European childhood cancer survivors: A qualitative PanCareFollowUp study

BACKGROUND

Healthy behaviors, that is, engaging in regular physical activities, maintaining a healthy diet, limiting alcohol consumption, and avoiding tobacco and drug use, decrease the risk of developing late adverse health conditions in childhood cancer survivors. However, childhood cancer survivors may experience barriers to adopting and maintaining healthy behaviors. This study aimed to assess these barriers and facilitators to health behavior adoption and maintenance in childhood cancer survivors.

METHODS

A focus group ( n  = 12) and semi-structured telephone interviews ( n  = 20) were conducted with a selected sample of European and Dutch childhood cancer survivors, respectively. The Theoretical Domains Framework (TDF) was used to inform the topic guide and analysis. Inductive thematic analysis was applied to identify categories relating to barriers and facilitators of health behavior adoption and maintenance, after which they were deductively mapped onto the TDF.

RESULTS

Ten TDF domains were identified in the data of which "Knowledge," "Beliefs about consequences," "Environmental context and resources," and "Social influences" were most commonly reported. Childhood cancer survivors expressed a need for knowledge on the importance of healthy behaviors, possibly provided by healthcare professionals. They indicated physical and long-term benefits of healthy behaviors, available professional support, and a supporting and health-consciously minded work and social environment to be facilitators. Barriers were mostly related to a lack of available time and an unhealthy environment. Lastly, (social) media was perceived as both a barrier and a facilitator to healthy behaviors.

CONCLUSION

This study has identified education and available professional support in health behaviors and the relevance of healthy behaviors for childhood cancer survivors as key opportunities for stimulating health behavior adoption in childhood cancer survivors. Incorporating health behavior support and interventions for this population should therefore be a high priority.

Neurocognitive function and health-related quality of life in a nationwide cohort of long-term childhood brain tumor survivors

Background

Childhood brain tumor survivors are at high risk of late effects, especially neurocognitive impairment. Limited data are available examining neurocognitive function and associations with quality of life (QoL) in childhood brain tumor survivors. Our aim was to examine neurocognitive function in childhood brain tumor survivors, and associations with QoL and symptom burden.

Methods

Five-year survivors of brain tumors over the age of 15 were identified in the Danish Childhood Cancer Registry (n = 423). Eligible and consenting participants completed neuropsychological tests and questionnaires assessing QoL, insomnia, fatigue, anxiety, and depression. Survivors treated with radiation (n = 59) were statistically compared with survivors not treated with radiation (n = 102).

Results

In total, 170 survivors participated (40.2% participation rate). Sixty-six percent of the survivors who completed neurocognitive tests (n = 161) exhibited overall neurocognitive impairment. Survivors treated with radiation, especially whole-brain irradiation, exhibited poorer neurocognitive outcomes than survivors not treated with radiation. Neurocognitive outcomes for survivors treated with surgery were below normative expectations. Furthermore, a number of survivors experienced significant fatigue (40%), anxiety (23%), insomnia (13%), and/or depression (6%). Survivors treated with radiation reported lower quality of life (QoL) and higher symptom burden scores than survivors not treated with radiation; particularly in physical functioning, and social functioning with symptoms of fatigue. Neurocognitive impairment was not associated with QoL or symptom burden.

Conclusions

In this study, a majority of the childhood brain tumor survivors experienced neurocognitive impairment, reduced QoL, and high symptom burden. Although not associated with each other, it is apparent that childhood brain tumor survivors experience not only neurocognitive dysfunction but may also experience QoL impairments and significant symptom burden.

Risk of subsequent primary lymphoma in a cohort of 69,460 five-year survivors of childhood and adolescent cancer in Europe: The PanCareSurFup study

BACKGROUND

Survivors of Hodgkin lymphoma (HL) are at risk of developing non-Hodgkin lymphoma (NHL) after treatment; however, the risks of developing subsequent primary lymphomas (SPLs), including HL and NHL, after different types of childhood cancer are unknown. The authors quantified the risk of SPLs using the largest cohort of childhood cancer survivors worldwide.

METHODS

The Pan-European Network for Care of Survivors After Childhood and Adolescent Cancer (PanCare) Survivor Care and Follow-Up Studies (PanCareSurFup) cohort includes 69,460 five-year survivors of childhood cancer, diagnosed during 1940 through 2008, from 12 European countries. Risks of SPLs were quantified by standardized incidence ratios (SIRs) and relative risks (RRs) using multivariable Poisson regression.

RESULTS

Overall, 140 SPLs, including 104 NHLs and 36 HLs, were identified. Survivors were at 60% increased risk of an SPL compared with the general population (SIR, 1.6; 95% confidence interval [CI], 1.4-1.9). Survivors were twice as likely to develop NHL (SIR, 2.3; 95% CI, 1.9-2.8), with the greatest risks among survivors of HL (SIR, 7.1; 95% CI, 5.1-10.0), Wilms tumor (SIR, 3.1; 95% CI, 1.7-5.7), leukemia (SIR, 2.8; 95% CI, 1.8-4.4), and bone sarcoma (SIR, 2.7; 95% CI, 1.4-5.4). Treatment with chemotherapy for any cancer doubled the RR of NHL (RR, 2.1; 95% CI, 1.2-3.9), but treatment with radiotherapy did not (RR, 1.2; 95% CI, 0.7-2.0). Survivors were at similar risk of developing a subsequent HL as the general population (SIR, 1.1; 95% CI, 0.8-1.5).

CONCLUSIONS

In addition to HL, the authors show here for the first time that survivors of Wilms tumor, leukemia, and bone sarcoma are at risk of NHL. Survivors and health care professionals should be aware of the risk of NHL in these survivors and in any survivors treated with chemotherapy.

Risk of subsequent primary oral cancer in a cohort of 69,460 5-year survivors of childhood and adolescent cancer in Europe: the PanCareSurFup study

BACKGROUND

Survivors of childhood cancer are at risk of subsequent primary malignant neoplasms (SPNs), but the risk for rarer types of SPNs, such as oral cancer, is uncertain. Previous studies included few oral SPNs, hence large-scale cohorts are required to identify groups at risks.

METHODS

The PanCareSurFup cohort includes 69,460 5-year survivors of childhood cancer across Europe. Risks of oral SPNs were defined by standardised incidence ratios (SIRs), absolute excess risks and cumulative incidence.

RESULTS

One hundred and forty-five oral SPNs (64 salivary gland, 38 tongue, 20 pharynx, 2 lip, and 21 other) were ascertained among 143 survivors. Survivors were at 5-fold risk of an oral SPN (95% CI: 4.4-5.6). Survivors of leukaemia were at greatest risk (SIR = 19.2; 95% CI: 14.6-25.2) followed by bone sarcoma (SIR = 6.4, 95% CI: 3.7-11.0), Hodgkin lymphoma (SIR = 6.2, 95% CI: 3.9-9.9) and soft-tissue sarcoma (SIR = 5.0, 95% CI: 3.0-8.5). Survivors treated with radiotherapy were at 33-fold risk of salivary gland SPNs (95% CI: 25.3-44.5), particularly Hodgkin lymphoma (SIR = 66.2, 95% CI: 43.6-100.5) and leukaemia (SIR = 50.5, 95% CI: 36.1-70.7) survivors. Survivors treated with chemotherapy had a substantially increased risk of a tongue SPN (SIR = 15.9, 95% CI: 10.6-23.7).

CONCLUSIONS

Previous radiotherapy increases the risk of salivary gland SPNs considerably, while chemotherapy increases the risk of tongue SPNs substantially. Awareness of these risks among both health-care professionals and survivors could play a crucial role in detecting oral SPNs early.

School performance of children with neurofibromatosis 1: a nationwide population-based study

Children with neurofibromatosis 1 (NF1) may have a high burden of somatic disease and cognitive impairments, which can lead to poor academic performance. We evaluated school grades from exams ending mandatory schooling (usually around age 15 or 16 years) of children with NF1 in a population-based registry study using a within-school matched design. The study included 285 children with NF1 and 12,000 NF1-free peers who graduated from the same school and year during 2002-2015. We estimated overall and gender-specific grades by subject and compared the grades of children with NF1 with those of NF1-free peers in linear regression models. We also examined the effect of social and socioeconomic factors (immigration status and parental education, income and civil status) on grades and age at finalizing ninth grade. School grades varied considerably by socioeconomic stratum for all children; however, children with NF1 had lower grades by an average of 11-12% points in all subjects. In the adjusted models, children with NF1 had significantly lower grades than their NF1-free peers, with largest negative differences in grades observed for girls with NF1. Finally, children with NF1 were 0.2 (CI 0.1-0.2) years older than their peers on graduating from ninth grade, but only maternal educational modified the age at graduating. In conclusion, students with NF1 perform more poorly than their peers in all major school subjects. Gender had a strong effect on the association between NF1 and school grades; however, socioeconomic factors had a similar effect on grades for children with NF1 and their peers.

Childhood cancer confers increased risk of migraine - A Danish nationwide register study

BACKGROUND

Investigations of migraine among childhood cancer survivors have predominantly relied on self-reported information and hospital discharge diagnoses. Alone, both approaches are liable to bias. We used Danish nationwide registers to obtain data on both prescriptions of acute migraine medications (antimigraines) and hospital discharge diagnoses of migraine to assess the relative risk of migraine across a wider spectrum of migraine presentations than previously studied.

METHODS

We followed a Danish population-based cohort of 7771 individuals with childhood cancer diagnosed in the period from Jan 1st, 1978 to Dec 31st, 2017, for risk of prescription antimigraine initiation and for risk of hospitalization due to migraine. Rates of hospitalization were assessed for the entire follow-up period whereas rates of antimigraine initiations were assessed in the period from Jan 1st, 1997, to Dec 31st, 2017. Relative to the general population without childhood cancer, standardized incidence ratios (SIRs) were calculated for each outcome.

RESULTS

Individuals exposed to childhood cancer were at increased risk of antimigraine initiation (SIR of 1.24, 95% CI: 1.11-1.38) and of migraine hospitalization (SIR of 2.44, 95% CI: 1.87-3.12) from the day of their cancer diagnosis and up to 40 years after.

CONCLUSIONS

Individuals diagnosed with childhood cancer have a higher risk of migraine of varying presentations, in addition to migraine resulting in hospitalization as previously reported. This potentially preventable problem warrants clinical attention.

Evaluating the feasibility, effectiveness and costs of implementing person-centred follow-up care for childhood cancer survivors in four European countries: the PanCareFollowUp Care prospective cohort study protocol

INTRODUCTION

Long-term survival after childhood cancer often comes at the expense of late, adverse health conditions. However, survivorship care is frequently not available for adult survivors in Europe. The PanCareFollowUp Consortium therefore developed the PanCareFollowUp Care Intervention, an innovative person-centred survivorship care model based on experiences in the Netherlands. This paper describes the protocol of the prospective cohort study (Care Study) to evaluate the feasibility and the health economic, clinical and patient-reported outcomes of implementing PanCareFollowUp Care as usual care in four European countries.

METHODS AND ANALYSIS

In this prospective, longitudinal cohort study with at least 6 months of follow-up, 800 childhood cancer survivors will receive the PanCareFollowUp Care Intervention across four study sites in Belgium, Czech Republic, Italy and Sweden, representing different healthcare systems. The PanCareFollowUp Care Intervention will be evaluated according to the Reach, Effectiveness, Adoption, Implementation and Maintenance framework. Clinical and research data are collected through questionnaires, a clinic visit for multiple medical assessments and a follow-up call. The primary outcome is empowerment, assessed with the Health Education Impact Questionnaire. A central data centre will perform quality checks, data cleaning and data validation, and provide support in data analysis. Multilevel models will be used for repeated outcome measures, with subgroup analysis, for example, by study site, attained age, sex or diagnosis.

ETHICS AND DISSEMINATION

This study will be conducted in accordance with the guidelines of Good Clinical Practice and the Declaration of Helsinki. The study protocol has been reviewed and approved by all relevant ethics committees. The evidence and insights gained by this study will be summarised in a Replication Manual, also including the tools required to implement the PanCareFollowUp Care Intervention in other countries. This Replication Manual will become freely available through PanCare and will be disseminated through policy and press releases.

TRIAL REGISTRATION NUMBER

Netherlands Trial Register (NL8918; https://www.trialregister.nl/trial/8918).

Cohort profile: life with neurofibromatosis 1 - the Danish NF1 cohort

PURPOSE

The Danish neurofibromatosis 1 (NF1) cohort was initiated to study health-related, socioeconomic and psychological consequences of living with the monogenetic disorder NF1 using a nationwide and population-based approach.

PARTICIPANTS

The cohort includes all 2467 individuals in Denmark who were hospitalised with or due to NF1 from 1977 to 2013 or registered in the RAREDIS Database (1995-2013), a national clinical database for rare diseases, or both. A comparison cohort matched to individuals with NF1 on sex and date of birth was identified in the Civil Registration System (n=20 132).

FINDINGS TO DATE

All cohort members were linked to the unique Danish registries to obtain information on hospital contacts, birth outcomes, education and partnership. A questionnaire was completed by 244 of the 629 adult cohort members with NF1 registered in the RAREDIS Database to evaluate the psychosocial and emotional burden. Further, neuropsychological tests were performed on 103 adult cohort members with NF1 and 38 adult population comparisons. To date, six studies have been published. Individuals with NF1 had an increased risk for (1) hospitalisation for disorders affecting all organ systems of the body throughout all decades of life, (2) psychiatric disorders, (3) attaining a short or medium long education and (4) not forming a life partner. Women with NF1 had an increased risk for spontaneous abortions and stillbirths. Finally, adults with NF1 had an impaired quality of life and a high need for professional support for physical, psychological and work-related problems, which was partly associated with disease severity and visibility.

FUTURE PLANS

The cohort will regularly be updated with newly diagnosed patients in the RAREDIS Database as well as with outcome information in the Danish registries. New studies are in progress to assess other medical and socioeconomic dimensions of living with NF1.

Effects of early maternal cancer and fertility treatment on the risk of adverse birth outcomes

BACKGROUND

Early maternal cancer and fertility treatment each increase the risk for adverse birth outcomes, but the joint effect of these outcomes has not yet been reported. Thus, the aim was to assess the individual and joint effect of maternal cancer and fertility treatment on the risk for adverse birth outcomes.

METHODS

This population-based cohort study included 5487 live-born singletons identified in the Danish Medical Birth Register (1994-2016) of mothers with previous cancer (<40 years) recorded in the Danish Cancer Registry (1955-2014). We randomly selected 80,262 live-born singletons of mothers with no cancer <40 years matched to mothers with cancer by birth year and month. We calculated odds ratios (ORs) for preterm birth, low birth weight (LBW) (<2500 g) and small for gestational age (SGA), mean differences in birth weight in grams, and additional cases of preterm birth (gestational age<259 days) per 100,000 person-years. Multiplicative and additive interaction of maternal cancer and fertility treatment was compared with outcomes of children conceived naturally to mothers with no maternal cancer (reference group).

FINDINGS

Among 84,332 live-born singletons, increased ORs for preterm birth were observed among children born to mothers with previous cancer (1·48, 95% confidence interval [CI] 1·33-1.65) or after fertility treatment (1·43, 95% 1·28-1-61), with 22 additional cases of preterm birth among both group of children (95% CI 15-29; 95% CI 14-30). In the joint analyses, the OR for SGA for children born after fertility treatment to mothers with previous cancer was similar to that of the reference group (OR 1·02, 95% CI 0·72-1·44, P for interaction=0·52). Children with both exposures had increased ORs for LBW (1·86, 95% CI 1·17-2·96, P for interaction=0·06) and preterm birth (2·31, 955 CI 1·66-3·20, P for interaction = 0·56), with 61 additional cases of preterm birth (95% CI 27-95, P for interaction=0.26) over that of children in the reference group. The mean birth weight was also lower in children born to mothers with both exposures (-140 g, 95% CI -215; -65) (P for interaction=0.06) but decreased to -22 g (95% CI -76; 31) after adjustment for GA.

INTERPRETATION

Although we did not find any statistically significant additive interaction between maternal cancer and fertility treatment, children born after fertility treatment of mothers with previous cancer were at increased risk for adverse birth outcomes. Thus, pregnant women with both exposures need close follow-up during pregnancy.

FUNDING

The Danish Cancer Society and the Danish Childhood Cancer Foundation.

Association Between Maternal Hormonal Contraception Use and Central Nervous System Tumors in Children

IMPORTANCE

The incidence of central nervous system (CNS) tumors in children appears to be increasing, yet few risk factors are established. There is limited information regarding whether maternal hormonal contraception use increases this risk.

OBJECTIVE

To examine the association between maternal hormonal contraception use and CNS tumors in children (<20 years).

DESIGN, SETTING, AND PARTICIPANTS

In this nationwide cohort study based on population-based registry data, 1 185 063 children born in Denmark between January 1, 1996, and December 31, 2014, were followed up for a diagnosis of a CNS tumor (final follow-up on December 31, 2018).

EXPOSURES

Maternal hormonal contraception use was analyzed according to any use, regimen (combined/progestin only), and route of administration (oral/nonoral), categorized as recent use (≤3 months before start and during pregnancy), previous use (>3 months before start of pregnancy), and no use. For injections, implants, and intrauterine devices that are used for a different time period, the categorization was appropriately altered.

MAIN OUTCOMES AND MEASURES

Hazard ratio (HR) and incidence rate difference (IRD) of CNS tumors diagnosed at younger than 20 years.

RESULTS

After 15 335 990 person-years of follow-up (mean follow-up, 12.9 years), 725 children were diagnosed with a CNS tumor. The mean age at diagnosis was 7 years, and 342 (47.2%) of the diagnosed children were female. The adjusted incidence rate of CNS tumors per 100 000 person-years was 5.0 for children born to mothers with recent hormonal contraception use (n = 136 022), 4.5 for children born to mothers with previous use (n = 778 843), and 5.3 for children born to mothers with no use (n = 270 198). The corresponding HRs were 0.95 ([95% CI, 0.74-1.23]; 84 children with CNS tumors; IRD, -0.3 [95% CI, -1.6 to 1.0]) for recent use and 0.86 ([95% CI, 0.72-1.02]; 421 children with CNS tumors; IRD, -0.8 [95% CI, -1.7 to 0.0]) for previous use, compared with no use. No statistically significant associations were found for recent or previous use of oral combined, nonoral combined, oral progestin only, or nonoral products compared with no use of hormonal contraception.

CONCLUSIONS AND RELEVANCE

Among Danish children, there was no statistically significant association between any maternal hormonal contraception use and CNS tumor risk.

International variation in childhood cancer mortality rates from 2001 to 2015: Comparison of trends in the International Cancer Benchmarking Partnership countries

Despite improved survival rates, cancer remains one of the most common causes of childhood death. The International Cancer Benchmarking Partnership (ICBP) showed variation in cancer survival for adults. We aimed to assess and compare trends over time in cancer mortality between children, adolescents and young adults (AYAs) and adults in the six countries involved in the ICBP: United Kingdom, Denmark, Australia, Canada, Norway and Sweden. Trends in mortality between 2001 and 2015 in the six original ICBP countries were examined. Age standardised mortality rates (ASR per million) were calculated for all cancers, leukaemia, malignant and benign central nervous system (CNS) tumours, and non-CNS solid tumours. ASRs were reported for children (age 0-14 years), AYAs aged 15 to 39 years and adults aged 40 years and above. Average annual percentage change (AAPC) in mortality rates per country were estimated using Joinpoint regression. For all cancers combined, significant temporal reductions were observed in all countries and all age groups. However, the overall AAPC was greater for children (-2.9; 95% confidence interval = -4.0 to -1.7) compared to AYAs (-1.8; -2.1 to -1.5) and adults aged >40 years (-1.5; -1.6 to -1.4). This pattern was mirrored for leukaemia, CNS tumours and non-CNS solid tumours, with the difference being most pronounced for leukaemia: AAPC for children -4.6 (-6.1 to -3.1) vs AYAs -3.2 (-4.2 to -2.1) and over 40s -1.1 (-1.3 to -0.8). AAPCs varied between countries in children for all cancers except leukaemia, and in adults over 40 for all cancers combined, but not in subgroups. Improvements in cancer mortality rates in ICBP countries have been most marked among children aged 0 to 14 in comparison to 15 to 39 and over 40 year olds. This may reflect better care, including centralised service provision, treatment protocols and higher trial recruitment rates in children compared to older patients.

Late mortality among survivors of childhood acute lymphoblastic leukemia diagnosed during 1971-2008 in Denmark, Finland, and Sweden: A population-based cohort study

OBJECTIVE

Investigate all-cause and cause-specific late mortality after childhood acute lymphoblastic leukemia (ALL) in a population-based Nordic cohort.

METHODS

From the cancer registries of Denmark, Finland, and Sweden, we identified 3765 five-year survivors of ALL, diagnosed before age 20 during 1971-2008. For each survivor, up to five matched comparison subjects were randomly selected from the general population (n = 18,323). Causes of death were classified as relapse related, health related, and external. Late mortality was evaluated by cumulative incidences of death from 5-year survival date. Mortality hazard ratios (HR) were evaluated with Cox proportional models.

RESULTS

Among the survivors, 315 deaths occurred during a median follow-up of 16 years from 5-year survival date (range 0-42). The majority were attributable to relapse (n = 224), followed by second neoplasm (n = 45). Cumulative incidence of all-cause late mortality at 15 years from diagnosis decreased gradually over treatment decades, from 14.4% (95% confidence interval [CI]: 11.6-17.2) for survivors diagnosed during 1971-1981, to 2.5% (95% CI: 1.3-3.7) for those diagnosed during 2002-2008. This was mainly attributable to a reduction in relapse-related deaths decreasing from 13.4% (95% CI: 10.7-16.1) for survivors diagnosed during 1971-1981 to 1.9% (95% CI: 0.9-2.8) for those diagnosed during 2002-2008. Health-related late mortality was low and did not change substantially across treatment decades. Compared to comparison subjects, all-cause mortality HR was 40 (95% CI: 26-61) 5-9 years from diagnosis, and 4.4 (95% CI: 3.4-5.6) ≥10 years from diagnosis.

CONCLUSIONS

Survivors of ALL have higher late mortality than population comparison subjects. Among the survivors, there was a temporal reduction in risk of death from relapse, without increments in health-related death.

Survival in Women Diagnosed With Breast Cancer During Pregnancy

INTRODUCTION

Pregnancy rarely coincides with breast cancer, but when it does, uncertainties remain about how survival is affected. In a nation-wide study, we investigated survival in women diagnosed with breast cancer during pregnancy.

MATERIALS AND METHODS

Through health registries, we identified women with breast cancer at ages 15-44 years from 1973-2016 in Denmark and included 156 who were pregnant at diagnosis and 11,110 who were not. We compared overall mortality in pregnant and non-pregnant women using multivariate Cox regression stratified by time since cancer: <2 and ≥2 years.

RESULTS

During the first 2 years after diagnosis, the hazard ratio of overall death was 2.28 (95% CI: 1.48-3.52) for pregnant versus non-pregnant breast cancer patients after adjustment for age and calendar period and 1.62 (95% CI: 1.05-2.50) after further adjustment for extent of disease. Adjusting for additional tumor characteristics, the hazard ratio was still significantly increased. Beyond the first 2 years, there was no excess mortality.

CONCLUSION

Our study identifies the early period after breast cancer as a period of particular interest in future studies on survival after breast cancer in pregnancy. We found no evidence that survival is affected by pregnancy when 2 or more years have passed since diagnosis.

Esophageal disease among childhood cancer survivors-A report from the Childhood Cancer Survivors Study

There is limited information addressing the occurrence of esophageal strictures among the growing population of survivors of childhood cancer. Using the Childhood Cancer Survivor Study, we analyzed data from 17,121 5-year survivors and 3400 siblings to determine the prevalence and risk factors for esophageal strictures. Prevalence among survivors was 2.0% (95% confidence interval [CI]: 1.8-2.2%), representing a 7.6-fold increased risk compared to siblings. Factors significantly associated with risk of esophageal stricture included diagnosis of Hodgkin lymphoma, greater chest radiation dose, younger age at cancer diagnosis, platinum chemotherapy, and hematopoietic stem cell transplantation. While uncommon, survivors are at risk for therapy-related esophageal strictures.

Psychiatric disorders in individuals with neurofibromatosis 1 in Denmark: A nationwide register-based cohort study

The aim of this study was to assess the risks of psychiatric disorders in a large cohort of 905 individuals with NF1 and 7614 population comparisons matched on sex and year of birth. The cohort was linked to the Danish Psychiatric Central Research Register to ascertain information on hospital contacts for psychiatric disorders based on the International Classification of Diseases version 8 and 10. The hazard ratio (HR) for a first psychiatric hospital contact was higher in girls (4.19, 95% confidence interval [CI] 1.81-9.69) and boys with NF1 (5.02, 95% CI 3.27-7.69) <7 years of age than in the population comparisons. Both sexes had increased HRs for developmental disorders, including attention deficit/hyperactivity disorders, autism spectrum disorders, and intellectual disabilities in childhood. Females with NF1 had also increased HRs for unipolar depression, other emotional and behavioral disorders, and severe stress reaction and adjustment disorders in early adulthood. The HRs for psychoses, schizophrenia, bipolar disorders, and substance abuse were similar in individuals with NF1 and the population comparisons. Finally, the cumulative incidence of a first hospital contact due to any psychiatric disorder by age 30 years was 35% (95% CI 29-41) in females and 28% (95% CI 19-37) in males with NF1. Thus, screening for psychiatric disorders may be important for early diagnosis and facilitation of appropriate and effective treatment in individuals with NF1.

Temporal changes in the probability of live birth among female survivors of childhood cancer: A Population-Based Adult Life After Childhood Cancer in Scandinavia (ALiCCS) study in five Nordic countries

BACKGROUND

During the past 4 decades, there has been a growing focus on preserving the fertility of patients with childhood cancer; however, no large studies have been conducted of live births across treatment decades during this period. Therefore, the authors estimated the potential birth deficit in female childhood cancer survivors and the probability of live births.

METHODS

In total, 8886 women were identified in the 5 Nordic cancer registries in whom a childhood cancer had been diagnosed during 1954 through 2006. A population comparison cohort of 62,903 women was randomly selected from the central population registries matched by age and country. All women were followed for live births recorded in medical birth registries. The cumulative probability and the risk ratio (RR) with 95% confidence intervals (CIs) of a live birth were calculated by maternal age across treatment decades.

RESULTS

The probability of a live birth increased with treatment decade, and, at age 30 years, the rate for survivors most recently diagnosed was close to the rate among the general population (1954-1969: RR, 0.65 [95% CI, 0.54-0.78]; 1970s: RR, 0.67 [95% CI, 0.60-0.74]; 1980s: RR, 0.69 [95% CI, 0.64-0.74]; 1990s: RR, 0.91 [95% CI, 0.87-0.95]; 2000s: RR, 0.94 [95% CI, 0.91-0.97]).

CONCLUSIONS

Female childhood cancer survivors had a lower probability of a live birth than women in the general population, although, in survivors diagnosed after 1989, the probability was close to that of the general population. Because the pattern of live births differs by cancer type, continuous efforts must be made to preserve fertility, counsel survivors, and refer them rapidly to fertility treatment if necessary.

LAY SUMMARY

The purpose of this study was to compare the probability of giving birth to a liveborn child in female survivors of childhood cancer with that of women in the general population. Survivors of childhood cancer had a lower probability of live births than women in the general population, although survivors diagnosed after 1989 had a probability close to that of the general population. Continuing focus on how to preserve the potential for fertility among female patients with childhood cancer during treatment is important to increase their chances of having a child.

TCERG1L allelic variation is associated with cisplatin-induced hearing loss in childhood cancer, a PanCareLIFE study

In children with cancer, the heterogeneity in ototoxicity occurrence after similar treatment suggests a role for genetic susceptibility. Using a genome-wide association study (GWAS) approach, we identified a genetic variant in TCERG1L (rs893507) to be associated with hearing loss in 390 non-cranial irradiated, cisplatin-treated children with cancer. These results were replicated in two independent, similarly treated cohorts (n = 192 and 188, respectively) (combined cohort: P = 5.3 × 10-10, OR 3.11, 95% CI 2.2-4.5). Modulating TCERG1L expression in cultured human cells revealed significantly altered cellular responses to cisplatin-induced cytokine secretion and toxicity. These results contribute to insights into the genetic and pathophysiological basis of cisplatin-induced ototoxicity.

The European multistakeholder PanCareFollowUp project: novel, person-centred survivorship care to improve care quality, effectiveness, cost-effectiveness and accessibility for cancer survivors and caregivers

BACKGROUND

The majority of childhood cancer survivors are at risk of treatment-related adverse health outcomes. Survivorship care to mitigate these late effects is endorsed, but it is not available for many adult survivors of childhood cancer in Europe. The PanCareFollowUp project was initiated to improve their health and quality of life (QoL) by facilitating person-centred survivorship care.

METHODS

The PanCareFollowUp consortium was established in 2018, consisting of 14 project partners from ten European countries, including survivor representatives. The consortium will develop two PanCareFollowUp Interventions, including a person-centred guideline-based model of care (Care Intervention) and eHealth lifestyle coaching (Lifestyle Intervention). Their development will be informed by several qualitative studies and systematic reviews on barriers and facilitators for implementation and needs and preferences of healthcare providers (HCPs) and survivors. Implementation of the PanCareFollowUp Care Intervention as usual care will be evaluated prospectively among 800 survivors from Belgium, Czech Republic, Italy and Sweden for survivor empowerment, detection of adverse health conditions, satisfaction among survivors and HCPs, cost-effectiveness and feasibility. The feasibility of the PanCareFollowUp Lifestyle Intervention will be evaluated in the Netherlands among 60 survivors.

RESULTS

Replication manuals, allowing for replication of the PanCareFollowUp Care and Lifestyle Intervention, will be published and made freely available after the project. Moreover, results of the corresponding studies are expected within the next five years.

CONCLUSIONS

The PanCareFollowUp project is a novel European collaboration aiming to improve the health and QoL of all survivors across Europe by developing and prospectively evaluating the person-centred PanCareFollowUp Care and Lifestyle Interventions.

Treatment-related fertility impairment in long-term female childhood, adolescent and young adult cancer survivors: investigating dose-effect relationships in a European case-control study (PanCareLIFE)

STUDY QUESTION

Which chemotherapeutic agents and body site-specific radiation fields are dose-dependently associated with an increased risk of fertility impairment in long-term female childhood, adolescent and young adulthood (CAYA) cancer survivors?

SUMMARY ANSWER

Busulfan, lower abdominal radiotherapy (RT) and total body irradiation (TBI) seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively.

WHAT IS KNOWN ALREADY

Several treatment-related fertility deficits, as assessed by both self-reported outcomes and hormonal markers are known to occur following treatment of CAYA cancer. However, knowledge regarding precise dose-related estimates of these treatment-related risks are scarce.

STUDY DESIGN, SIZE, DURATION

The current case-control study was nested within the PanCareLIFE cohort study. In total, 1332 CAYA survivors from 8 countries, 9 institutions and 11 cohorts, participated in and contributed data to the study.

PARTICIPANTS/MATERIALS, SETTING, METHODS

All participants were female 5-year CAYA cancer survivors. In total, 450 cases (fertility impaired survivors) and 882 matched controls (not fertility impaired survivors) were included. Fertility impairment was defined using both questionnaire data (primary or secondary amenorrhea; use of artificial reproductive techniques; unfulfilled wish to conceive) and hormonal data (FSH and anti-Müllerian hormone (AMH)). Multivariable logistic regression models were used to investigate the effect of (i) alkylating agent exposure, and (ii) dose categories for individual chemotherapeutic agents and for RT-exposed body sites.

MAIN RESULTS AND THE ROLE OF CHANCE

A positive dose-effect relationship between cyclophosphamide equivalent dose (CED) score and fertility impairment was found, with survivors with a CED score > 7121 mg/m2 being at a significantly increased risk of fertility impairment (odds ratio (95% CI) = 2.6 (1.9-3.6) P < 0.001). Moreover, cumulative dose variables of the following treatments were significantly associated with fertility impairment: busulfan, carmustine, cyclophosphamide, melphalan, procarbazine, lower abdominal RT and TBI. Busulfan, lower abdominal RT and TBI seem to be associated with fertility impairment at any dose, whereas gonadotoxicity of melphalan and procarbazine is suggested at medium/high (>140 mg/m2) or high dose (>5600 mg/m2) therapy, respectively.

LIMITATIONS, REASONS FOR CAUTION

Our study may have been subject to selection bias since data from about half of the original base cohorts were available for the current study. This could impact the generalizability of our study results.

WIDER IMPLICATIONS OF THE FINDINGS

We identified survivors at high risk for fertility impairment and, consequently, for a reduced or even absent reproductive life span. Both girls and young women who are about to start anti-cancer treatment, as well as adult female survivors, should be counselled about future parenthood and referred to a reproductive specialist for fertility preservation, if desired.

STUDY FUNDING/COMPETING INTEREST(S)

This study has received funding from the European Union's Seventh Framework Programme for research, technological development and demonstration under grant agreement no. 602030. There are no competing interests.

TRIAL REGISTRATION NUMBER

n/a.

Pregnancy outcomes in women with neurofibromatosis 1: a Danish population-based cohort study

BACKGROUND

The probability of a pregnancy, live birth, stillbirth and abortion has never been assessed in women with neurofibromatosis 1 (NF1) in a large population-based study.

METHODS

We included 1006 women (15-49 years) registered with NF1 in the Danish National Patient Registry or followed in two national Centers for Rare Diseases and 10 020 women from the Danish population. Information on pregnancy outcomes was ascertained from health registries. Cumulative incidence, mean cumulative count, hazard ratios (HRs) and proportion ratios (PRs) with 95% CIs were calculated.

RESULTS

The cumulative incidence of a first pregnancy at age 50 years was slightly lower in women with NF1 (74%; 95% CI 70 to 77) than in population comparisons (78%; 95% CI 77 to 79). When all pregnancies were included, two pregnancies were expected per woman at age of 50 years, irrespective of a NF1 diagnosis. The hazard of a pregnancy did not differ between women with NF1 (HR 1.03; 95% CI 0.95 to 1.11) and the comparisons after adjustment for somatic and psychiatric disease. The proportion of pregnancies that resulted in a live birth was 63% (783/1252) among women NF1 and 68% (8432/12 465) among the comparisons, yielding a PR of 0.95 (95% CI 0.90 to 1.00). The proportions of stillbirths (PR 2.83; 95% CI 1.63 to 4.93) and spontaneous abortions (PR 1.40; 95% CI 1.09 to 1.79) were increased in women with NF1.

CONCLUSIONS

A similar hazard for pregnancy was observed for women with NF1 and population comparisons after adjustment for potential medical consequences of NF1. However, women with NF1 experienced more spontaneous abortions and stillbirths.

Risk of digestive cancers in a cohort of 69 460 five-year survivors of childhood cancer in Europe: the PanCareSurFup study

BACKGROUND

Survivors of childhood cancer are at risk of subsequent primary neoplasms (SPNs), but the risk of developing specific digestive SPNs beyond age 40 years remains uncertain. We investigated risks of specific digestive SPNs within the largest available cohort worldwide.

METHODS

The PanCareSurFup cohort includes 69 460 five-year survivors of childhood cancer from 12 countries in Europe. Risks of digestive SPNs were quantified using standardised incidence ratios (SIRs), absolute excess risks and cumulative incidence.

RESULTS

427 digestive SPNs (214 colorectal, 62 liver, 48 stomach, 44 pancreas, 59 other) were diagnosed in 413 survivors. Wilms tumour (WT) and Hodgkin lymphoma (HL) survivors were at greatest risk (SIR 12.1; 95% CI 9.6 to 15.1; SIR 7.3; 95% CI 5.9 to 9.0, respectively). The cumulative incidence increased the most steeply with increasing age for WT survivors, reaching 7.4% by age 55% and 9.6% by age 60 years (1.0% expected based on general population rates). Regarding colorectal SPNs, WT and HL survivors were at greatest risk; both seven times that expected. By age 55 years, 2.3% of both WT (95% CI 1.4 to 3.9) and HL (95% CI 1.6 to 3.2) survivors had developed a colorectal SPN-comparable to the risk among members of the general population with at least two first-degree relatives affected.

CONCLUSIONS

Colonoscopy surveillance before age 55 is recommended in many European countries for individuals with a family history of colorectal cancer, but not for WT and HL survivors despite a comparable risk profile. Clinically, serious consideration should be given to the implementation of colonoscopy surveillance while further evaluation of its benefits, harms and cost-effectiveness in WT and HL survivors is undertaken.

Large variation in assessment and outcome definitions to describe the burden of long-term morbidity in childhood cancer survivors: A systematic review

We systematically reviewed outcome assessment methods, outcome classification, and severity grading of reported outcomes in studies investigating the burden of physical long-term morbidity in childhood cancer survivors (CCS). A MEDLINE and EMBASE search identified 56 studies reporting on three or more types of health conditions in 5-year CCS, for which information was extracted on outcome types and classification, methods of outcome ascertainment, and severity grading. There was substantial variability in classification and types of health conditions reported and in methods of outcome ascertainment. Only 59% of the included studies applied severity grading, mainly the common terminology criteria of adverse events. This large variation in assessment and definition of the burden of physical long-term morbidity in CCS challenges interpretation, comparison, and pooling data across studies. Global collaboration is needed to standardize assessments and harmonize definitions of long-term physical morbidity and associated outcomes in childhood cancer survivorship research.

Association of candidate pharmacogenetic markers with platinum-induced ototoxicity: PanCareLIFE dataset

Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in a pharmacogenetic guideline. The PanCareLIFE cross-sectional cohort study evaluated the genetic associations in a large pan-European population and assessed the diagnostic accuracy of the genetic markers. 1,112 pediatric cancer survivors who had provided biomaterial for genotyping were screened for participation in the pharmacogenetic association study. 900 participants qualified for inclusion. Based on the assessment of original audiograms, patients were assigned to three phenotype categories: no, minor, and clinically relevant hearing loss. Fourteen variants in eleven candidate genes (ABCC3, OTOS, TPMT, SLC22A2, NFE2L2, SLC16A5, LRP2, GSTP1, SOD2, WFS1, and ACYP2) were genotyped. The genotype and phenotype data represent a resource for conducting meta-analyses to derive a more precise pooled estimate of the effects of genes on the risk of hearing loss due to platinum treatment.

Usefulness of current candidate genetic markers to identify childhood cancer patients at risk for platinum-induced ototoxicity: Results of the European PanCareLIFE cohort study

BACKGROUND

Irreversible sensorineural hearing loss is a common side effect of platinum treatment with the potential to significantly impair the neurocognitive, social and educational development of childhood cancer survivors. Genetic association studies suggest a genetic predisposition for cisplatin-induced ototoxicity. Among other candidate genes, thiopurine methyltransferase (TPMT) is considered a critical gene for susceptibility to cisplatin-induced hearing loss in a pharmacogenetic guideline. The aim of this cross-sectional cohort study was to confirm the genetic associations in a large pan-European population and to evaluate the diagnostic accuracy of the genetic markers.

METHODS

Eligibility criteria required patients to be aged less than 19 years at the start of chemotherapy, which had to include cisplatin and/or carboplatin. Patients were assigned to three phenotype categories: no, minor and clinically relevant hearing loss. Fourteen variants in eleven candidate genes (ABCC3, OTOS, TPMT, SLC22A2, NFE2L2, SLC16A5, LRP2, GSTP1, SOD2, WFS1 and ACYP2) were investigated. Multinomial logistic regression was performed to model the relationship between genetic predictors and platinum ototoxicity, adjusting for clinical risk factors. Additionally, measures of the diagnostic accuracy of the genetic markers were determined.

RESULTS

900 patients were included in this study. In the multinomial logistic regression, significant unique contributions were found from SLC22A2 rs316019, the age at the start of platinum treatment, cranial radiation and the interaction term [platinum compound]∗[cumulative dose of cisplatin]. The predictive performance of the genetic markers was poor compared with the clinical risk factors.

CONCLUSIONS

PanCareLIFE is the largest study of cisplatin-induced ototoxicity to date and confirmed a role for the polyspecific organic cation transporter SLC22A2. However, the predictive value of the current genetic candidate markers for clinical use is negligible, which puts the value of clinical factors for risk assessment of cisplatin-induced ototoxicity back into the foreground.

Hospital admission for neurologic disorders among 5-year survivors of noncentral nervous system tumors in childhood: A cohort study within the Adult Life after Childhood Cancer in Scandinavia study

Large, comprehensive studies of the risk for neurologic disorders among long-term survivors of noncentral nervous system (CNS) childhood cancers are lacking. Thus, the aim of our study was to assess the lifetime risk of Nordic non-CNS childhood cancer survivors for neurologic disorders. We identified 15,967 5-year survivors of non-CNS childhood cancer diagnosed in Denmark, Iceland, Finland and Sweden in 1943-2008, and 151,118 matched population comparison subjects. In-patient discharge diagnoses of neurologic disorders were used to calculate relative risks (RRs) and absolute excess risks (AERs). A neurologic disorder was diagnosed in 755 of the survivors while 370 were expected, yielding a RR of 2.0 (95% confidence interval (CI) 1.9-2.2). The highest risks were found among survivors of neuroblastoma (4.1; 95% CI 3.2-5.3) and leukemia (2.8; 95% CI 2.4-3.2). The AER decreased from 331 (278-383) excess neurologic disorders per 100,000 person-years 5-9 years after diagnosis to 82 (46-118) ≥ 20 years after diagnosis. Epilepsy was the most common diagnosis (n = 229, 1.4% of all survivors), and significantly increased risks were seen among survivors of eight out of 12 types of childhood cancer. Survivors of neuroblastoma had remarkably high risks (RR ≥ 10) for hospitalization for paralytic syndromes and hydrocephalus, while survivors of leukemia had additional high risks for dementia and encephalopathy. In conclusion, survivors of non-CNS childhood cancer are at high risk for neurologic disorders, especially within the first decade after diagnosis. Therefore, intensive follow-up to identify those who require close management is needed.

Risk factors for cardiovascular disease in 5-year survivors of adolescent and young adult cancer: A Danish population-based cohort study

BACKGROUND

An increased risk of metabolic syndrome has been reported for childhood cancer survivors and for adult survivors with certain cancer types. One previous study reported on the risk for diseases in the metabolic syndrome specifically among survivors of adolescent and young adult cancers.

METHODS

The study comprised 11,822 five-year survivors of adolescent and young adult cancer (ages 15-39 years at diagnosis) who were diagnosed during the period from 1994 through 2009 in Denmark and a population-based comparison cohort of 76,024 individuals. The cohorts were linked to Danish nationwide registries for information on hospital contacts and purchase of prescription drugs related to metabolic syndrome, respectively. Standardized rate ratios (RRs) for hospital contacts (SHRRs) and prescriptions (SPRRs) with 95% CIs were calculated for diabetes, hyperlipidemia, and hypertension.

RESULTS

Survivors had increased risks for hospital contacts and prescriptions for diabetes (SHRR, 1.21; 95% CI, 1.03-1.43; SPRR, 1.08; 95% CI, 0.96-1.23), hyperlipidemia (SHRR, 1.18; 95% CI, 1.00-1.40; SPRR, 1.16; 95% CI, 1.08-1.25), and hypertension (SHRR, 1.27; 95% CI, 1.15-1.41; SPRR, 1.25; 95% CI, 1.20-1.31). The highest risks for hospitalizations were among survivors of brain cancer (RR, 2.94 for diabetes) and Hodgkin lymphoma (RR, 2.40 for diabetes). Survivors of brain cancer and Hodgkin lymphoma were most likely to purchase prescription drugs for diseases in metabolic syndrome.

CONCLUSIONS

Survivors of adolescent and young adult cancer are at increased risk of hospital contacts and purchase of prescription drugs for diseases in metabolic syndrome. Survivors at high risk should be followed closely to improve prevention, early detection, and management of these diseases to ultimately minimize the risk of cardiovascular diseases.

Risk of subsequent primary leukaemias among 69,460 five-year survivors of childhood cancer diagnosed from 1940 to 2008 in Europe: A cohort study within PanCareSurFup

BACKGROUND

Survivors of childhood cancers are at risk of developing subsequent primary leukaemias (SPLs), but the long-term risks beyond 20 years of treatment are still unclear. We investigated the risk of SPLs in five-year childhood cancer survivors using a large-scale pan-European (PanCareSurFup) cohort and evaluated variations in the risk by cancer and demographic factors.

METHODS

This largest-ever assembled cohort comprises 69,460 five-year childhood cancer survivors from 12 European countries. Standardised incidence ratios (SIRs) and absolute excess risks (AERs) were calculated.

RESULTS

One hundred fifteen survivors developed an SPL including 86 myeloid leukaemias (subsequent primary myeloid leukaemias [SPMLs]), 17 lymphoid leukaemias and 12 other types of leukaemias; of these SPLs, 31 (27%) occurred beyond 20 years from the first childhood cancer diagnosis. Compared with the general population, childhood cancer survivors had a fourfold increased risk (SIR = 3.7, 95% confidence interval [CI]: 3.1 to 4.5) of developing leukaemia, and eight leukaemias per 100,000 person-years (AER = 7.5, 95% CI: 6.0 to 9.2) occurred in excess of that expected. The risks remained significantly elevated beyond 20 years from the first primary malignancy (SIR = 2.4, 95% CI: 1.6 to 3.4). Overall, the risk ratio for SPML (SIR = 5.8, 95% CI: 4.6 to 7.1) was higher than that for other SPLs.

CONCLUSIONS

We demonstrate that beyond 20 years after childhood cancer diagnosis, survivors experience an increased risk for SPLs compared with that expected from the general population. Our findings highlight the need for awareness by survivors and their healthcare providers for potential risk related to SPL.

Genetic Determinants of Ototoxicity During and After Childhood Cancer Treatment: Protocol for the PanCareLIFE Study

Background

Survival rates after childhood cancer now reach nearly 80% in developed countries. However, treatments that lead to survival and cure can cause serious adverse effects with lifelong negative impacts on survivor quality of life. Hearing impairment is a common adverse effect in children treated with cisplatin-based chemotherapy or cranial radiotherapy. Ototoxicity can extend from high-tone hearing impairment to involvement of speech frequencies. Hearing impairment can impede speech and language and neurocognitive development. Although treatment-related risk factors for hearing loss following childhood cancer treatment have been identified, the individual variability in toxicity of adverse effects after similar treatment between childhood cancer patients suggests a role for genetic susceptibility. Currently, 12 candidate gene approach studies have been performed to identify polymorphisms predisposing to platinum-induced ototoxicity in children being treated for cancer. However, results were inconsistent and most studies were underpowered and/or lacked replication.

Objective

We describe the design of the PanCareLIFE consortium’s work packages that address the genetic susceptibility of platinum-induced ototoxicity.

Methods

As a part of the PanCareLIFE study within the framework of the PanCare consortium, we addressed genetic susceptibility of treatment-induced ototoxicity during and after childhood cancer treatment in a large European cohort by a candidate gene approach and a genome-wide association screening.

Results

This study included 1124 survivors treated with cisplatin, carboplatin, or cranial radiotherapy for childhood cancer, resulting in the largest clinical European cohort assembled for this late effect to date. Within this large cohort we defined a group of 598 cisplatin-treated childhood cancer patients not confounded by cranial radiotherapy. The PanCareLIFE initiative provided, for the first time, a unique opportunity to confirm already identified determinants for hearing impairment during childhood cancer using a candidate gene approach and set up the first international genome-wide association study of cisplatin-induced direct ototoxicity in childhood cancer patients to identify novel allelic variants. Results will be validated in an independent replication cohort. Patient recruitment started in January 2015 and final inclusion was October 2017. We are currently performing the analyses and the first results are expected by the end of 2019 or the beginning of 2020. 

Conclusions

Genetic factors identified as part of this pan-European project, PanCareLIFE, may contribute to future risk prediction models that can be incorporated in future clinical trials of platinum-based therapies for cancer and may help with the development of prevention strategies.

International Registered Report Identifier (IRRID)

DERR1-10.2196/11868

Hyperthyroidism as a late effect in childhood cancer survivors - an Adult Life after Childhood Cancer in Scandinavia (ALiCCS) study

BACKGROUND

Hyperthyroidism is a rare disorder which may negatively affect health and quality of life. Its occurrence in childhood cancer survivors has not previously been investigated in detail.

MATERIAL AND METHODS

In the hospital registers of the five Nordic countries, 32,944 childhood cancer survivors and 212,675 population comparisons were followed for the diagnosis of hyperthyroidism. Hospitalisation rates, standardised hospitalisation rate ratios and absolute excess risks were calculated with 95% confidence intervals (CI).

RESULTS

Hyperthyroidism was diagnosed in 131 childhood cancer survivors, yielding an overall relative risk of 1.6 (95% CI: 1.3-1.9) compared with population comparisons. The risk was greatest 1-5 years after the diagnosis of cancer and in survivors of thyroid cancers, neuroblastomas, acute lymphoblastic leukaemia and Hodgkin lymphoma. Sixty-seven percent of survivors with hyperthyroidism had tumours located in the head, neck or upper body and half of survivors with hyperthyroidism were irradiated with 77% of them in the head and neck area.

CONCLUSION

Childhood cancer survivors are at an increased risk of hyperthyroidism, potentially resulting in non-endocrine morbidity.

Risk of cardiovascular disease among Nordic childhood cancer survivors with diabetes mellitus: A report from adult life after childhood cancer in Scandinavia

BACKGROUND

Childhood cancer survivors have an increased risk of cardiovascular disease (CVD) and diabetes mellitus. Because diabetes is a potentially modifiable risk factor for CVD in the general population, it is important to understand how diabetes affects the risk of CVD among childhood cancer survivors.

METHODS

This study examined the risk of CVD among survivors with diabetes and 142,742 population comparison subjects. From the national cancer registries of the 5 Nordic countries, 29,324 one-year survivors of cancer diagnosed before the age of 20 years between 1968 and 2008 were identified. Study subjects were linked to the national hospital registers. The cumulative incidence of CVD was determined with competing risk methods. A Cox proportional hazards model was used to estimate the effects of diabetes and cancer on the hazard of CVD. The interaction between diabetes and cancer was analyzed.

RESULTS

Diabetes was diagnosed in 324 of the 29,324 one-year survivors, and CVD was diagnosed in 2108. The hazard of diabetes was 1.7 times higher among survivors than comparison subjects (hazard ratio [HR], 1.7; 95% confidence interval [CI], 1.5-1.9), whereas the HR of CVD was 3.6 (95% CI, 3.3-3.8) 1 to 15 years after the cancer diagnosis and 1.9 (95% CI, 1.8-2.0) after more than 15 years. Individuals with diabetes had a 2.4 times higher hazard of CVD (95% CI, 2.1-2.8) among both survivors and comparison subjects in comparison with individuals without diabetes.

CONCLUSIONS

Childhood cancer survivors with diabetes have a markedly increased risk of CVD in comparison with survivors without diabetes. However, diabetes does not increase the risk of CVD more in survivors than the general population.

Fertility Among Female Survivors of Childhood, Adolescent, and Young Adult Cancer: Protocol for Two Pan-European Studies (PanCareLIFE)

Background

Despite a significant number of studies on female fertility following childhood, adolescent, and young adult (CAYA) cancer, studies establishing precise (dose-related) estimates of treatment-related risks are still scarce. Previous studies have been underpowered, did not include detailed treatment information, or were based on self-report only without any hormonal assessments. More precise assessments of who is at risk for sub- or infertility are needed.

Objective

The objective of our study is to describe the design and methods of 2 studies on female fertility (a cohort study and a nested case-control study) among female survivors of CAYA cancer performed within the European PanCareLIFE project.

Methods

For the cohort study, which aims to evaluate the overall risk of fertility impairment, as well as the risk for specific subgroups of female CAYA cancer survivors, 13 institutions from 9 countries provide data on fertility impairment. Survivors are defined as being fertility impaired if they meet at least one of 8 different criteria based on self-reported and hormonal data. For the nested case-control study, which aims to identify specific treatment-related risk factors associated with fertility impairment in addition to possible dose-response relationships, cases (fertility impaired survivors) are selected from the cohort study and matched to controls (survivors without fertility impairment) on a 1:2 basis.

Results

Of the 10,964 survivors invited for the cohort study, data are available from 6619 survivors, either questionnaire-based only (n=4979), hormonal-based only (n=72), or both (n=1568). For the nested case-control study, a total of 450 cases and 882 controls are identified.

Conclusions

Results of both PanCareLIFE fertility studies will provide detailed insight into the risk of fertility impairment following CAYA cancer and diagnostic- or treatment-related factors associated with an increased risk. This will help clinicians to adequately counsel both girls and young women, who are about to start anticancer treatment, as well as adult female CAYA cancer survivors, concerning future parenthood and to timely refer them for fertility preservation. Ultimately, we aim to empower patients and survivors and improve their quality of life.

Registered Report Identifier

RR1-10.2196/10824

Models of Care for Survivors of Childhood Cancer From Across the Globe: Advancing Survivorship Care in the Next Decade

With improvements in cancer treatment and supportive care, a growing population of survivors of childhood cancer at risk for significant and potentially life-threatening late effects has been identified. To provide a current snapshot of the models of care from countries with varying levels of resources and health care systems, stakeholders in childhood cancer survivorship clinical care and research were identified from 18 countries across five continents. Stakeholders responded to a survey and provided a brief narrative regarding the current state of survivorship care. Findings indicate that among pediatric-age survivors of childhood cancer (allowing for differences in age cutoffs across countries), resources are generally available, and a large proportion of survivors are seen by a physician familiar with late effects in most countries. After survivors transition to adulthood, only a minority are seen by a physician familiar with late effects. Despite the need to improve communication between pediatric oncology and primary care, only a few countries have existing national efforts to educate primary care physicians, although many more reported that educational programs are in development. These data highlight common challenges and potential solutions for the lifelong care of survivors of childhood cancer. Combining risk-based and patient-oriented solutions for this population is likely to benefit both providers and patients.

Risk of Soft-Tissue Sarcoma Among 69 460 Five-Year Survivors of Childhood Cancer in Europe

Background

Childhood cancer survivors are at risk of subsequent primary soft-tissue sarcomas (STS), but the risks of specific STS histological subtypes are unknown. We quantified the risk of STS histological subtypes after specific types of childhood cancer.

Methods

We pooled data from 13 European cohorts, yielding a cohort of 69 460 five-year survivors of childhood cancer. Standardized incidence ratios (SIRs) and absolute excess risks (AERs) were calculated.

Results

Overall, 301 STS developed compared with 19 expected (SIR = 15.7, 95% confidence interval [CI] = 14.0 to 17.6). The highest standardized incidence ratios were for malignant peripheral nerve sheath tumors (MPNST; SIR = 40.6, 95% CI = 29.6 to 54.3), leiomyosarcomas (SIR = 29.9, 95% CI = 23.7 to 37.2), and fibromatous neoplasms (SIR = 12.3, 95% CI = 9.3 to 16.0). SIRs for MPNST were highest following central nervous system tumors (SIR = 80.5, 95% CI = 48.4 to 125.7), Hodgkin lymphoma (SIR = 81.3, 95% CI = 35.1 to 160.1), and Wilms tumor (SIR = 76.0, 95% CI = 27.9 to 165.4). Standardized incidence ratios for leiomyosarcoma were highest following retinoblastoma (SIR = 342.9, 95% CI = 245.0 to 466.9) and Wilms tumor (SIR = 74.2, 95% CI = 37.1 to 132.8). AERs for all STS subtypes were generally low at all years from diagnosis (AER < 1 per 10 000 person-years), except for leiomyosarcoma following retinoblastoma, for which the AER reached 52.7 (95% CI = 20.0 to 85.5) per 10 000 person-years among patients who had survived at least 45 years from diagnosis of retinoblastoma.

Conclusions

For the first time, we provide risk estimates of specific STS subtypes following childhood cancers and give evidence that risks of MPNSTs, leiomyosarcomas, and fibromatous neoplasms are particularly increased. While the multiplicative excess risks relative to the general population are substantial, the absolute excess risk of developing any STS subtype is low, except for leiomyosarcoma after retinoblastoma. These results are likely to be informative for both survivors and health care providers.

Liver diseases in Adult Life after Childhood Cancer in Scandinavia (ALiCCS): A population-based cohort study of 32,839 one-year survivors

Information on late onset liver complications after childhood cancer is scarce. To ensure an appropriate follow-up of childhood cancer survivors and reducing late liver complications, the need for comprehensive and accurate information is presented. We evaluate the risk of liver diseases in a large childhood cancer survivor cohort. We included all 1-year survivors of childhood cancer treated in the five Nordic countries. A Cox proportional hazards model was used to estimate hospitalisation rate (hazard) ratios (HRs) for each liver outcome according to type of cancer. We used the risk among survivors of central nervous system tumour as internal reference. With a median follow-up time of 10 years, 659 (2%) survivors had been hospitalised at least once for a liver disease. The risk for hospitalisation for any liver disease was high after hepatic tumour (HR = 6.9) and leukaemia (HR = 1.7). The Danish sub-cohort of leukaemia treated with haematopoietic stem cell transplantation had a substantially higher risk for hospitalisation for all liver diseases combined (HR = 3.8). Viral hepatitis accounted for 286 of 659 hospitalisations corresponding to 43% of all survivors hospitalised for liver disease. The 20-year cumulative risk of viral hepatitis was 1.8% for survivors diagnosed with cancer before 1990 but only 0.3% for those diagnosed after 1990. The risk of liver disease was low but significantly increased among survivors of hepatic tumours and leukaemia. Further studies with focus on the different treatment modalities are needed to further strengthen the prevention of treatment-induced late liver complications.

Risk of Subsequent Bone Cancers Among 69 460 Five-Year Survivors of Childhood and Adolescent Cancer in Europe

Introduction

We investigate the risks of subsequent primary bone cancers after childhood and adolescent cancer in 12 European countries. For the first time, we satisfactorily address the risks beyond 40 years from diagnosis and beyond 40 years of age among all survivors.

Methods

This largest-ever assembled cohort comprises 69 460 five-year survivors of cancer diagnosed before age 20 years. Standardized incidence ratios, absolute excess risks, and multivariable-adjusted relative risks and relative excess risks were calculated. All statistical tests were two-sided.

Results

Overall, survivors were 21.65 times (95% confidence interval = 18.97 to 24.60 times) more likely to be diagnosed with a subsequent primary bone cancer than expected from the general population. The greatest excess numbers of bone cancers were observed after retinoblastoma, bone sarcoma, and soft tissue sarcoma. The excess number of bone cancers declined linearly with both years since diagnosis and attained age (all P < .05). Beyond 40 years from diagnosis and age 40 years, there were at most 0.45 excess bone cancers among all survivors per 10 000 person-years at risk; beyond 30 years from diagnosis and age 30 years, there were at most 5.02 excess bone cancers after each of retinoblastoma, bone sarcoma, and soft tissue sarcoma, per 10 000 person-years at risk.

Conclusions

For all survivors combined and the cancer groups with the greatest excess number of bone cancers, the excess numbers observed declined with both age and years from diagnosis. These results provide novel, reliable, and unbiased information about risks and risk factors among long-term survivors of childhood and adolescent cancer.

Long-term inpatient disease burden in the Adult Life after Childhood Cancer in Scandinavia (ALiCCS) study: A cohort study of 21,297 childhood cancer survivors

BACKGROUND

Survivors of childhood cancer are at increased risk for a wide range of late effects. However, no large population-based studies have included the whole range of somatic diagnoses including subgroup diagnoses and all main types of childhood cancers. Therefore, we aimed to provide the most detailed overview of the long-term risk of hospitalisation in survivors of childhood cancer.

METHODS AND FINDINGS

From the national cancer registers of Denmark, Finland, Iceland, and Sweden, we identified 21,297 5-year survivors of childhood cancer diagnosed with cancer before the age of 20 years in the periods 1943-2008 in Denmark, 1971-2008 in Finland, 1955-2008 in Iceland, and 1958-2008 in Sweden. We randomly selected 152,231 population comparison individuals matched by age, sex, year, and country (or municipality in Sweden) from the national population registers. Using a cohort design, study participants were followed in the national hospital registers in Denmark, 1977-2010; Finland, 1975-2012; Iceland, 1999-2008; and Sweden, 1968-2009. Disease-specific hospitalisation rates in survivors and comparison individuals were used to calculate survivors' standardised hospitalisation rate ratios (RRs), absolute excess risks (AERs), and standardised bed day ratios (SBDRs) based on length of stay in hospital. We adjusted for sex, age, and year by indirect standardisation. During 336,554 person-years of follow-up (mean: 16 years; range: 0-42 years), childhood cancer survivors experienced 21,325 first hospitalisations for diseases in one or more of 120 disease categories (cancer recurrence not included), when 10,999 were expected, yielding an overall RR of 1.94 (95% confidence interval [95% CI] 1.91-1.97). The AER was 3,068 (2,980-3,156) per 100,000 person-years, meaning that for each additional year of follow-up, an average of 3 of 100 survivors were hospitalised for a new excess disease beyond the background rates. Approximately 50% of the excess hospitalisations were for diseases of the nervous system (19.1% of all excess hospitalisations), endocrine system (11.1%), digestive organs (10.5%), and respiratory system (10.0%). Survivors of all types of childhood cancer were at increased, persistent risk for subsequent hospitalisation, the highest risks being those of survivors of neuroblastoma (RR: 2.6 [2.4-2.8]; n = 876), hepatic tumours (RR: 2.5 [2.0-3.1]; n = 92), central nervous system tumours (RR: 2.4 [2.3-2.5]; n = 6,175), and Hodgkin lymphoma (RR: 2.4 [2.3-2.5]; n = 2,027). Survivors spent on average five times as many days in hospital as comparison individuals (SBDR: 4.96 [4.94-4.98]; n = 422,218). The analyses of bed days in hospital included new primary cancers and recurrences. Of the total 422,218 days survivors spent in hospital, 47% (197,596 bed days) were for new primary cancers and recurrences. Our study is likely to underestimate the absolute overall disease burden experienced by survivors, as less severe late effects are missed if they are treated sufficiently in the outpatient setting or in the primary health care system.

CONCLUSIONS

Childhood cancer survivors were at increased long-term risk for diseases requiring inpatient treatment even decades after their initial cancer. Health care providers who do not work in the area of late effects, especially those in primary health care, should be aware of this highly challenged group of patients in order to avoid or postpone hospitalisations by prevention, early detection, and appropriate treatments.

Effect of socioeconomic position on survival after childhood cancer in Denmark

Background One fifth of all deaths among children in Europe are accounted for by cancer. If this is to be reduced there is a need for studies on not only biology and treatment approaches but also on how social factors influence cure rates. We investigated how various socioeconomic characteristics were associated with survival after childhood cancer. Material and methods In a nationwide cohort of 3797 children diagnosed with cancer [hematological cancer, central nervous system (CNS) tumors, non-CNS solid tumors] before age 20 between 1990 and 2009 we identified parents and siblings and obtained individual level parental socioeconomic variables and vital status through 2012 by linkage to population-based registries. Hazard ratios (HR) and 95% confidence intervals (CI) for dying were estimated using multivariate Cox proportional hazard models. Results For all children with cancer combined, survival was slightly but not statistically significantly better the higher the education of the mother or the father, and with maternal income. Significantly better survival was observed when parents were living together compared to living alone and worse survival when the child had siblings compared to none. Young (<20) or older (≥40) maternal age showed non-significant associations, but based on small numbers. For hematological cancers, no significant associations were observed. For CNS tumors, better survival was seen with parents living together (HR 0.70, CI 0.51-0.97). For non-CNS solid tumors, survival was better with high education of the mother (HR 0.66, CI 0.44-0.99) compared to basic and worse for children with one (HR 1.45, CI 1.11-1.89) or two or more siblings (HR 1.29, CI 0.93-1.79) (p for trend 0.02) compared to none. Conclusion The impact of socioeconomic characteristics on childhood cancer survival, despite equal access to protocolled and free-of-charge treatment, warrants further and more direct studies of underlying mechanisms in order to target these as a means to improve survival rates.

The Adult Life After Childhood Cancer in Scandinavia (ALiCCS) Study: Design and Characteristics

BACKGROUND

During the last five decades, survival of childhood cancer has increased from 25% to 80%. At the same time, however, it has become evident that survivors experience a broad range of therapy-related late adverse health effects. The aim of the Adult Life after Childhood Cancer in Scandinavia (ALiCCS) study is to investigate long-term health consequences of past and current therapies in order to improve follow-up care of survivors and to reduce treatment-related morbidity of future patients.

PROCEDURE

Childhood cancer survivors were identified through the five Nordic cancer registries and a comparison cohort was established through random selection of cancer-free individuals from the civil registration systems. A unique personal identification number was used to link between different health registries. Abstraction of treatment information for a subset of survivors allows investigation of the association between the various components of cancer therapy and late occurring comorbidity.

RESULTS

The childhood cancer survivor cohort comprises 33,160 1-year survivors and the comparison cohort comprises 212,892 cancer free individuals from the general population. In the childhood cancer survivor cohort, all types of childhood cancer are represented including leukemia (21%), lymphoma (14%), central nervous system tumors (24%), sarcomas (5%), retinoblastoma (3%), and neuroblastoma (4%). Among the survivors, 22% have been followed beyond the age of 40 years.

CONCLUSION

The ALiCCS study constitutes a new large resource for research on late effects of childhood cancers that include all types of childhood malignancies and has followed a large proportion of the survivors well into late adulthood.

Childhood cancer survivor cohorts in Europe

With the advent of multimodality therapy, the overall five-year survival rate from childhood cancer has improved considerably now exceeding 80% in developed European countries. This growing cohort of survivors, with many years of life ahead of them, has raised the necessity for knowledge concerning the risks of adverse long-term sequelae of the life-saving treatments in order to provide optimal screening and care and to identify and provide adequate interventions. Childhood cancer survivor cohorts in Europe. Considerable advantages exist to study late effects in individuals treated for childhood cancer in a European context, including the complementary advantages of large population-based cancer registries and the unrivalled opportunities to study lifetime risks, together with rich and detailed hospital-based cohorts which fill many of the gaps left by the large-scale population-based studies, such as sparse treatment information. Several large national cohorts have been established within Europe to study late effects in individuals treated for childhood cancer including the Nordic Adult Life after Childhood Cancer in Scandinavia study (ALiCCS), the British Childhood Cancer Survivor Study (BCCSS), the Dutch Childhood Oncology Group (DCOG) LATER study, and the Swiss Childhood Cancer Survivor Study (SCCSS). Furthermore, there are other large cohorts, which may eventually become national in scope including the French Childhood Cancer Survivor Study (FCCSS), the French Childhood Cancer Survivor Study for Leukaemia (LEA), and the Italian Study on off-therapy Childhood Cancer Survivors (OTR). In recent years significant steps have been taken to extend these national studies into a larger pan-European context through the establishment of two large consortia - PanCareSurFup and PanCareLIFE. The purpose of this paper is to present an overview of the current large, national and pan-European studies of late effects after childhood cancer. This overview will highlight the strong cooperation across Europe, in particular the EU-funded collaborative research projects PanCareSurFup and PanCareLIFE. Overall goal. The overall goal of these large cohort studies is to provide every European childhood cancer survivor with better care and better long-term health so that they reach their full potential, and to the degree possible, enjoy the same quality of life and opportunities as their peers.

Very low-level heteroplasmy mtDNA variations are inherited in humans

Little is known about the inheritance of very low heteroplasmy mitochondria DNA (mtDNA) variations. Even with the development of new next-generation sequencing methods, the practical lower limit of measured heteroplasmy is still about 1% due to the inherent noise level of the sequencing. In this study, we sequenced the mitochondrial genome of 44 individuals using Illumina high-throughput sequencing technology and obtained high-coverage mitochondria sequencing data. Our study population contains many mother-offspring pairs. This unique study design allows us to bypass the usual heteroplasmy limitation by analyzing the correlation of mutation levels at each position in the mtDNA sequence between maternally related pairs and non-related pairs. The study showed that very low heteroplasmy variants, down to almost 0.1%, are inherited maternally and that this inheritance begins to decrease at about 0.5%, corresponding to a bottleneck of about 200 mtDNA.