Clinical Characteristics and Management of Children and Adults with Neurofibromatosis Type 1 and Plexiform Neurofibromas in Denmark: A Nationwide Study.

INTRODUCTION: Plexiform neurofibromas (PN) are benign nerve sheath tumours that are a frequent and potentially debilitating complication in patients with neurofibromatosis type 1 (NF1). The objective of this study was to describe the natural history of PN in children, adolescents and adults with NF1. METHODS: This was a nationwide, longitudinal cohort study of patients with NF1 under observation at the two national centres of NF1 expertise in Denmark between 2000 and 2020. Patient and clinical characteristics were documented from individual medical records. RESULTS: A total of 1099 patients with NF1 were included. Overall, 12% (35/296) of paediatric patients and 21% (172/803) of adult patients had ≥ 1 large PN (≥ 3 cm). Approximately half of patients with a large PN had ≥ 1 symptomatic PN. The most frequent symptoms were pain, neurological deficits, cosmetic issues, disfigurement, compression, increased psychosocial burden and vision loss. Clinical evaluations of PN size were available for 40 PN in 34 paediatric patients and 191 PN in 159 adult patients with large PN. Surgery (complete resection or debulking) was performed in 38% (15/40) of PN in paediatric patients and 45% (86/191) in adult patients. In addition, 35% of PN in paediatric patients and 33% in adult patients were inoperable. In a subgroup analysis, the overall PN size increased 1.06-fold per year. Malignant peripheral nerve sheath tumours (MPNST) were diagnosed in 21 patients (two paediatric and 19 adult patients). CONCLUSIONS: This study shows that PN are common, their size and prevalence increase with age, many are often inoperable and pain and other symptoms are frequently associated. The results highlight the severe sequelae and unmet need for alternatives to analgesia and surgery in patients with PN.

Short-acting ß2 -agonist use and asthma exacerbations in Swedish children: A SABINA Junior study.

BACKGROUND: In adults and adolescents with asthma, use of ≥3 short-acting ß2 -agonist (SABA) canisters/year is associated with increased exacerbation risk. Whether this association is present in younger children remains unknown. In this SABA use IN Asthma (SABINA) Junior study, we assessed the association of SABA collection with exacerbation risk in the general Swedish pediatric asthma population. METHODS: This population-based cohort study utilized linked data from the Swedish national healthcare registries involving patients with asthma (<18 years) treated in secondary care between 2006-2015. Exacerbation risk, by baseline SABA collection (0-2 vs. ≥3 canisters, further examined as ordinal/continuous variable) and stratified on comorbid atopic disease (allergic rhinitis, dermatitis and eczema, and food/other allergies), was assessed for 1-year follow-up using negative binomial regression. RESULTS: Of 219,561 patients assessed, 45.4%, 31.7%, and 26.5% of patients aged 0-5, 6-11, and 12-17 years, respectively, collected ≥3 SABA canisters during the baseline year (high use). Collection of ≥3 SABA canisters (vs. 0-2) was associated with increased exacerbation risk during follow-up (incidence rate ratios [95% confidence interval]: 1.35 [1.29-1.42], 1.22 [1.15-1.29], and 1.26 [1.19-1.34] for 0-5-, 6-11-, and 12-17-year-olds, respectively); the association persisted with SABA as a continuous variable and was stronger among patients without atopic diseases (32%-44% increased risk versus. 14%-21% for those with atopic disease across groups). CONCLUSIONS: High SABA use was associated with increased asthma exacerbation risk in children, particularly in those without comorbid atopic diseases, emphasizing the need for asthma medication reviews and reformative initiatives by caregivers and healthcare providers on SABA use.

Lack of COPD-Related Follow-Up Visits and Pharmacological Treatment in Swedish Primary and Secondary Care.

Objective: The Swedish guidelines recommend that patients with chronic obstructive pulmonary disease (COPD) on maintenance treatment are monitored annually, and within six weeks after an exacerbation. We describe the patterns of COPD-related visits in Sweden, both regular follow-up and post-exacerbation visits. Methods: Patients (>40 years) with a first-time COPD diagnosis between 2006 and 2017 were identified in primary care medical records and linked to hospital contacts and administered drug data. The index date was defined as the first collection of inhaled COPD maintenance treatment after the diagnosis. Regular COPD visits within 15-months after the index, and post-exacerbation visits for COPD within six weeks and 15-months after an exacerbation were estimated using the cumulative incidence function adjusted for competing risk. Visits without a ICD code for COPD were not included in the analyses. Results: A total of 19,857 patients (mean age 69 years, 57% females) were included. The overall probability of having a regular follow-up visit for COPD within 15 months post-index was 39.1%. In total, 15,095 (76%) patients experienced at least one COPD exacerbation during the observation period. Among them, the probability of having a post-exacerbation visit was 7.0% within six weeks and 29.7% within 15-months. Patients without a regular COPD follow-up visit claimed significantly more oral corticosteroids (25.6% vs 15.6%), more respiratory antibiotics (39.1% vs 23.1%), and less maintenance treatment (10.9% vs 16.5%). Conclusion: Only 39% of COPD patients attended a regular follow-up visit within 15-months from the COPD diagnosis and one-third had a post-exacerbation visit. The adherence to guideline recommendations need to be improved.

Annual and Post-Exacerbation Follow-Up of Asthma Patients in Clinical Practice - A Large Population-Based Study in Sweden.

Background: Symptom control has not improved in Swedish asthma patients during the last two decades. Guidelines recommend annual reviews for asthma patients treated with maintenance inhaled corticosteroids (ICS). We aimed to describe how visit patterns in an ICS-treated asthma population in Sweden were related to applicable asthma guidelines. Methods: Swedish electronic health data for incident asthma patients, ≥18 years, with at least one ICS collection (index date) between 2006 and 2017 were included. Exacerbations were defined as hospitalizations, emergency visits, or collection of oral corticosteroids (OCS). Probability of an asthma-related regular follow-up visit and probability of a follow-up visit after an exacerbation, both within 15 months, were estimated using the cumulative incidence function, time-to-event analysis, and incident rate ratios. Results: In 51,349 asthma patients (mean age 47.6 years, 63% females), 17,573 had a regular asthma visit in primary or secondary care within 15 months after the index, yielding an overall probability of a visit of 37.4%. Patients with a follow-up visit had higher ICS collection and lower OCS collection than patients without regular visits. Among 22,097 patients with acute exacerbations, the probability of a visit within 15 months after an exacerbation was 31.0%. The probability of having a visit increased during the study period. Conclusion: Only one-third of ICS-treated asthma patients, regardless of asthma severity, had a regular or post-exacerbation follow-up visit within a 15-month period. The consequences of this lack of adherence to guidelines need further evaluation to secure optimal asthma management.

Disease Trajectories and Impact of One Moderate Exacerbation in Gold B COPD Patients.

Introduction: Studies have shown that exacerbation in chronic obstructive pulmonary disease (COPD) increases the risk of further exacerbations. Our aim was to investigate the impact of a single moderate exacerbation on the odds of subsequent exacerbations and death in GOLD B COPD patients. Methods: This hospital-based nationwide, cohort study in Denmark included all patients ≥40 years of age with an in- and/or outpatient ICD-10 J44 diagnosis (COPD Register, 2008-2014). Index was date of first registered modified Medical Research Council (mMRC) score ≥2; baseline period was 12 months pre-index. At index, patients were grouped as: B0, no exacerbation; and B1, one moderate exacerbation during the previous year, and followed for three consecutive years in 2008-2017 for development of moderate- (short-term use of prednisolone or prednisone) and severe (emergency visit or hospitalization) exacerbations and death. Using B0 as reference, the odds ratio (OR) for exacerbation and death in GOLD B1 was estimated with multinominal logistic regression and a Cox model estimated the hazard ratio for exacerbation accounting for recurrent events. Results: In total, 8,453 patients (mean age 70 years, 51% male) were included, of which GOLD B0 4,545 and GOLD B1 3,908 patients. During the 3-year follow-up, 34.1% and 24.9% of GOLD B0 and B1, respectively, had none or one moderate exacerbation whereas 61.9% and 71.2% of B0 and B1, respectively, had a severe trajectory with multiple moderate and/or a severe exacerbation or died. In B1 patients, the OR for 1 moderate, ≥2 moderate exacerbations, ≥1 severe exacerbation was 1.58 [CI 1.33-1.87], 2.60 [2.19-3.08], 2.08 [1.76-2.45], respectively, and 1.85 [1.57-2.17] for death compared with B0. Conclusion: One moderate exacerbation in COPD patients with high symptom burden increases the odds of subsequent exacerbations and death during the three following years. The results emphasize the importance of preventing exacerbations in GOLD B patients.

Economic Burden of COPD by Disease Severity - A Nationwide Cohort Study in Denmark.

BACKGROUND: Chronic Obstructive Pulmonary Disease (COPD) carries a considerable economic burden, both for individuals and societies. This study aimed to assess direct and indirect costs associated with COPD, and how costs vary across disease severity. METHODS: This was a nationwide, population-based cohort study utilizing Danish health registries. Patients; ≥40 years of age, with an in- and/or outpatient diagnosis of COPD (ICD-10 J44) in 2008-2016, were identified in the nationwide Danish COPD Registry. Included patients were matched 1:4 to a population-based non-COPD reference population of 196,623 individuals by sex, year of birth, co-habitation status, and municipality. Patients were grouped by disease severity according to different characteristics including GOLD groups A-D, based on moderate (short-term oral corticosteroid use), presence of severe exacerbations (emergency visit or hospitalization) and symptom score. Index was the date of the first outpatient visit with a symptom score registration. The costs were calculated during a 12 months post-index follow-up. RESULTS: In all, 49,826 patients with COPD (mean age 69.2 years, 52% females) were included. Total annual costs, including direct costs, costs for elderly care, and costs for retirement home, were higher for patients with COPD (€28,969) compared with the reference population (€10,6913). In GOLD groups A-D, the total direct costs were A: €8,766, B: €13,060, C: €11,113, and D: €17,749, respectively. A major driver of direct costs was severe exacerbations. The mean costs per moderate and severe exacerbation were €888 and €7,091, respectively, during 28 days of follow-up. The costs for non-COPD-related Health Care Resource Utilization were higher than the COPD-related costs in GOLD groups A-C, but not in GOLD group D. CONCLUSION: In this nationwide real-world study, total direct costs were three-fold higher among patients with COPD compared with the reference population. Severe exacerbations were a major driver of the direct costs. The costs increased with increasing disease severity.

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.

Long-Term Risk of Hospitalization Among Five-Year Survivors of Childhood Leukemia in the Nordic Countries.

BACKGROUND: Adverse effects from childhood leukemia treatment may persist or present years after cure from cancer. We provide a comprehensive evaluation of subsequent hospitalization in five-year survivors of childhood acute lymphoblastic leukemia (ALL), acute myeloid leukemia (AML), and chronic myeloid leukemia (CML). METHODS: In the Adult Life after Childhood Cancer in Scandinavia Study, we identified 4003 five-year survivors diagnosed with childhood leukemia 1970-2008 in Denmark, Sweden, Iceland, and Finland. Survivors and 129 828 population comparisons were followed for first-time nonpsychiatric hospitalizations for 120 disease categories in the hospital registries. Standardized hospitalization rate ratios and absolute excess rates were calculated. All statistical tests were two-sided. RESULTS: Survivors of ALL (n = 3391), AML (n = 389), and CML (n = 92) had an increased overall hospitalization rate compared with population comparisons. The rate ratio for any hospitalization was 1.95 (95% confidence interval [CI] = 1.83 to 2.07) in ALL, 3.09 (95% CI = 2.53 to 3.65) in AML, and 4.51 (95% CI = 3.03 to 6.00) in CML survivors and remained increased even 20 years from leukemia diagnosis. Corresponding absolute excess rates per 1000 person-years were 28.48 (95% CI = 24.96 to 32.00), 62.75 (95% CI = 46.00 to 79.50), and 105.31 (95% CI = 60.90 to 149.72). CONCLUSION: Leukemia survivors have an increased rate of hospitalization for medical conditions. We provide novel insight into the relative and absolute rate of hospitalization for 120 disease categories in survivors of ALL, AML, and CML, which are likely to be informative for both survivors and healthcare providers.

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.

Disease-specific Hospitalizations Among 5-Year Survivors of Hepatoblastoma: A Nordic Population-based Cohort Study.

INTRODUCTION: The long-term risk of somatic disease in hepatoblastoma survivors has not been thoroughly evaluated in previous studies. In this population-based study of 86 five-year HB survivors, we used inpatient registers to evaluate the risk for a range of somatic diseases. METHODS: In total, 86 five-year survivors of hepatoblastoma were identified in the Nordic cancer registries from 1964 to 2008 and 152,231 population comparisons were selected. Study subjects were followed in national hospital registries for somatic disease classified into 12 main diagnostic groups. Standardized hospitalization rate ratios (RRs) and absolute excess risks were calculated. RESULTS: After a median follow-up of 11 years, 35 of the 86 five-year hepatoblastoma survivors had been hospitalized with a total of 69 hospitalizations, resulting in an RR of 2.7 (95% confidence interval [CI], 2.2-3.5) and an overall absolute excess risk of 4.2 per 100 person-years. Highest risk was seen for benign neoplasms (RR=16) with 6 hospitalizations for benign neoplasms in the colon and one in rectum. CONCLUSIONS: The pattern of hospitalizations found in this first comprehensive follow-up of hepatoblastoma survivors seems reassuring. Less than 50% of the 5-year survivors had been hospitalized and often for diseases that were not severe or life-threatening.

Endocrine Late Effects in Survivors of Cancer in Adolescence and Young Adulthood: A Danish Population-Based Cohort Study.

Importance: As survival rates from cancer have improved dramatically over the last decades, there is a need to explore the long-term consequences. Adolescents and young adults with cancer are at risk for several therapy-related late effects; however, these have not been studied extensively. Objective: To investigate the lifetime risks of endocrine late effects of cancer and cancer treatment in adolescent and young adult cancer survivors. Design, Setting, and Participants: This Danish, nationwide, population-based cohort study was conducted from January 1, 1976, through December 31, 2009, and included follow-up from January 1, 1977, through December 31, 2010. A total of 32 548 one-year cancer survivors diagnosed at ages 15 to 39 years were identified using the Danish Cancer Registry and 188 728 cancer-free comparison participants matched by year of birth and sex were randomly chosen from the Danish Civil Registration system. Analyses were performed from July 3, 2015, to February 27, 2018. Exposures: Individuals in the survivor cohort were diagnosed with a first primary cancer at ages 15 to 39 years and received treatment according to recommendations and guidelines at time of diagnosis. Main Outcomes and Measures: By linkage to the National Patient Register, all hospital contacts for endocrine diseases were identified, and standardized hospitalization rate ratios (RRs) and absolute excess risks (AERs) were calculated. Results: A total of 32 548 adolescent and young adult 1-year cancer survivors (14 021 [43.1%] male) in the Danish Patient Registry were followed up for 379 157 person-years (median [range]: 10 [0-34] years) and 188 728 cancer-free participants (82 669 [43.8%] male) for comparison were followed up for 2 958 994 person-years (median [range]: 15 [0-34] years). A total of 2129 survivors (6.5%) had at least 1 hospital contact for an endocrine disease, while 1232.0 (3.8%) were expected, yielding a statistically significant increased RR of 1.73 (95% CI, 1.65-1.81). The RRs were highest for testicular hypofunction (75.12; 95% CI, 45.99-122.70), ovarian hypofunction (14.65; 95% CI, 8.29-25.86), and pituitary hypofunction (11.14; 95% CI, 8.09-15.34). The leading reasons for hospital contacts were thyroid disease (38.0% of total AER), testicular dysfunction (17.1% of total AER), and diabetes (14.4% of total AER). Leukemia survivors were at a high risk for any endocrine disease (RR, 3.97; 95% CI, 3.10-5.09), while Hodgkin lymphoma survivors (RR, 3.06; 95% CI, 2.62-3.57) had the highest disease-specific excess risk for hypothyroidism (AER, 362 per 100 000 person-years; 95% CI, 280-443 per 100 000 person-years). Conclusions and Relevance: The increased risk for endocrine diseases in adolescent and young adult cancer survivors indicates the need for counseling and follow-up, and could guide future preventive measures and surveillance strategies. Additional studies are required to determine exact associations between treatment regimens and endocrine diseases.

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.

Measuring childhood cancer late effects: evidence of a healthy survivor effect.

INTRODUCTION: Given considerable focus on health outcomes among childhood cancer survivors, we aimed to explore whether survivor bias is apparent during long-term follow-up of childhood cancer survivors. METHODS: We identified all 1-year survivors of cancer diagnosed before 20 years of age in Denmark, Finland, Iceland, and Sweden. From the general population, we randomly sampled a comparison cohort. Study individuals were followed for hospitalizations for diseases of the gastroenterological tract, endocrine system, cardiovascular system, or urinary tract from the start of the cancer registries to 2010. We estimated cumulative incidence with death as competing risk and used threshold regression to compare the hazards of the diseases of interest at ages 20, 40, 60, and 75 years. RESULTS: Our study included 27,007 one-year survivors of childhood cancer and 165,620 individuals from the general population. The cumulative incidence of all four outcomes was higher for childhood cancer survivors during early adulthood, but for three outcomes, the cumulative incidence was higher for the general population after age 55 years. The hazard ratios (HRs) decreased for all outcomes with increasing age, and for two of the outcomes, the hazards were higher for the general population at older ages (endocrine diseases: age-specific HRs = 3.0, 1.4, 1.0, 0.87; Cardiovascular diseases: age-specific HRs = 4.1, 1.4, 0.97, 0.84). CONCLUSIONS: Our findings provide empirical evidence that survivor bias attenuates measures of association when comparing survivors with the general population. The design and analysis of studies among childhood cancer survivors, particularly as this population attains older ages, should account for survivor bias to avoid misinterpreting estimates of disease burden.

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.

Long-term risk of renal and urinary tract diseases in childhood cancer survivors: A population-based cohort study.

BACKGROUND: Childhood cancer has been associated with long-term risk of urinary tract diseases, but risk patterns remain to be comprehensively investigated. We analysed the lifetime risk of urinary tract diseases in survivors of childhood cancer in the Nordic countries. METHODS: We identified 32,519 one-year survivors of childhood cancer diagnosed since the 1940s and 1950s in the five Nordic cancer registries and selected 211,156 population comparisons of a corresponding age, sex, and country of residence from the national population registries. To obtain information on all first-time hospitalizations for a urinary tract disease, we linked all study subjects to the national hospital registry of each country. Relative risks (RRs) and absolute excess risks (AERs) and associated 95% confidence intervals (CIs) for urinary tract diseases among cancer survivors were calculated with the appropriate morbidity rates among comparisons as reference. RESULTS: We observed 1645 childhood cancer survivors ever hospitalized for urinary tract disease yielding an RR of 2.5 (95% CI 2.4-2.7) and an AER of 229 (95% CI 210-248) per 100,000 person-years. The cumulative risk at age 60 was 22% in cancer survivors and 10% in comparisons. Infections of the urinary system and chronic kidney disease showed the highest excess risks, whereas survivors of neuroblastoma, hepatic and renal tumours experienced the highest RRs. CONCLUSION: Survivors of childhood cancer had an excess risk of urinary tract diseases and for most diseases the risk remained elevated throughout life. The highest risks occurred following therapy of childhood abdominal tumours.

Gastrointestinal and liver disease in Adult Life After Childhood Cancer in Scandinavia: A population-based cohort study.

Survival after childhood cancer diagnosis has remarkably improved, but emerging evidence suggests that cancer-directed therapy may have adverse gastrointestinal late effects. We aimed to comprehensively assess the frequency of gastrointestinal and liver late effects among childhood cancer survivors and compare this frequency with the general population. Our population-based cohort study included all 1-year survivors of childhood and adolescent cancer in Denmark, Finland, Iceland, Norway and Sweden diagnosed from the 1940s and 1950s. Our outcomes of interest were hospitalization rates for gastrointestinal and liver diseases, which were ascertained from national patient registries. We calculated standardized hospitalization rate ratios (RRs) and absolute excess rates comparing hospitalizations of any gastrointestinal or liver disease and for specific disease entities between survivors and the general population. The study included 31,132 survivors and 207,041 comparison subjects. The median follow-up in the hospital registries were 10 years (range: 0-42) with 23% of the survivors being followed at least to the age of 40 years. Overall, survivors had a 60% relative excess of gastrointestinal or liver diseases [RR: 1.6, 95% confidence interval (CI): 1.6-1.7], which corresponds to an absolute excess of 360 (95% CI: 330-390) hospitalizations per 100,000 person-years. Survivors of hepatic tumors, neuroblastoma and leukemia had the highest excess of gastrointestinal and liver diseases. In addition, we observed a relative excess of several specific diseases such as esophageal stricture (RR: 13; 95% CI: 9.2-20) and liver cirrhosis (RR: 2.9; 95% CI: 2.0-4.1). Our findings provide useful information about the breadth and magnitude of late complications among childhood cancer survivors and can be used for generating hypotheses about potential exposures related to these gastrointestinal and liver late effects.

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.