Presence and utility of electrocardiographic abnormalities in long-term childhood cancer survivors.

BACKGROUND: We assessed the prevalence and diagnostic value of ECG abnormalities for cardiomyopathy surveillance in childhood cancer survivors. METHODS: In this cross-sectional study, 1381 survivors (≥5 years) from the Dutch Childhood Cancer Survivor Study part 2 and 272 siblings underwent a long-term follow-up ECG and echocardiography. We compared ECG abnormality prevalences using the Minnesota Code between survivors and siblings, and within biplane left ventricular ejection fraction (LVEF) categories. Among 880 survivors who received anthracycline, mitoxantrone or heart radiotherapy, logistic regression models using least absolute shrinkage and selection operator identified ECG abnormalities associated with three abnormal LVEF categories (<52% in male/<54% in female, <50% and <45%). We assessed the overall contribution of these ECG abnormalities to clinical regression models predicting abnormal LVEF, assuming an absence of systolic dysfunction with a <1% threshold probability. RESULTS: 16% of survivors (52% female, mean age 34.7 years) and 14% of siblings had major ECG abnormalities. ECG abnormalities increased with decreasing LVEF. Integrating selected ECG data into the baseline model significantly improved prediction of sex-specific abnormal LVEF (c-statistic 0.66 vs 0.71), LVEF <50% (0.66 vs 0.76) and LVEF <45% (0.80 vs 0.86). While no survivor met the preset probability threshold in the first two models, the third model used five ECG variables to predict LVEF <45% and was applicable for ruling out (sensitivity 93%, specificity 56%, negative predictive value 99.6%). Calibration and internal validation tests performed well. CONCLUSION: A clinical prediction model with ECG data (left bundle branch block, left atrial enlargement, left heart axis, Cornell's criteria for left ventricular hypertrophy and heart rate) may aid in ruling out LVEF <45%.

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.

Extensive Cardiac Function Analyses Using Contemporary Echocardiography in Childhood Cancer Survivors: A DCCSS LATER Study.

Background: Childhood cancer survivors (CCS) are at risk for cardiotoxicity. Objectives: We sought to assess how cardiac dysfunction measurements in CCS overlap and are differentially influenced by risk factors. Methods: This cross-sectional Dutch Childhood Cancer Survivor Study evaluated echocardiograms of 1,397 ≥5-year CCS and 277 siblings. Of CCS, n = 1,254 received cardiotoxic (anthracyclines/mitoxantrone/radiotherapy involving the heart region [RTheart]) and n = 143 received potentially cardiotoxic (cyclophosphamide, ifosfamide, or vincristine) therapy. We assessed demographic, treatment-related, and traditional cardiovascular risk factors for cardiac dysfunction using multivariable logistic regression. Results: CCS were a median of 26.7 years after diagnosis; 49% were women. Abnormal left ventricular ejection fraction (LVEF) (defined as <52% in men, <54% in women) occurred most commonly in CCS treated with anthracyclines and RTheart combined (38%). Age/sex-specific abnormal global longitudinal strain (GLS) occurred most commonly in CCS treated with RTheart, either with (41%) or without (38%) anthracyclines. Of CCS with normal LVEF, 20.2% showed abnormal GLS. Diastolic dysfunction grade ≥II was rare. Abnormal LVEF was mainly associated with female sex, anthracycline dose, and only in women, RTheart dose. Abnormal GLS was associated with female sex, RTheart dose, diastolic blood pressure, and only in women, anthracycline dose. Cyclophosphamide, ifosfamide, and vincristine were not associated with LVEF or GLS. Compared with siblings, CCS showed higher risk of abnormal LVEF (OR: 2.9; 95% CI: 1.4-6.6) and GLS (OR: 2.1; 95% CI: 1.2-3.7), independent of (potentially) cardiotoxic treatment-related and cardiovascular risk factors. Conclusions: Abnormal LVEF and GLS constitute complementary measures of systolic dysfunction among long-term CCS. Their diagnostic value may differ according to cardiotoxic exposures. Also, CCS have residual, unexplained risk of cardiac dysfunction. (Early Detection of Cardiac Dysfunction in Childhood Cancer Survivors, a DCOG LATER study; NTR7481).

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.

Adverse late health outcomes among children treated with 3D radiotherapy techniques: Study design of the Dutch pediatric 3D-RT study.

BACKGROUND: Adverse late health outcomes after multimodal treatment for pediatric cancer are diverse and of prime interest. Currently available evidence and survivorship care guidelines are largely based on studies addressing side-effects of two dimensional planned radiotherapy. AIMS: The Dutch pediatric 3D-planned radiotherapy (3D-RT) study aims to gain insight in the long-term health outcomes among children who had radiotherapy in the 3D era. Here, we describe the study design, data-collection methods, and baseline cohort characteristics. METHODS AND RESULTS: The 3D-RT study represents an expansion of the Dutch Childhood Cancer Survivor study (DCCSS) LATER cohort, including pediatric cancer patients diagnosed during 2000-2012, who survived at least 5 years after initial diagnosis and 2 years post external beam radiotherapy. Individual cancer treatment parameters were obtained from medical files. A national infrastructure for uniform collection and archival of digital radiotherapy files (Computed Tomography [CT]-scans, delineations, plan, and dose files) was established. Health outcome information, including subsequent tumors, originated from medical records at the LATER outpatient clinics, and national registry-linkage. With a median follow-up of 10.9 (interquartile range [IQR]: 7.9-14.3) years after childhood cancer diagnosis, 711 eligible survivors were identified. The most common cancer types were Hodgkin lymphoma, medulloblastoma, and nephroblastoma. Most survivors received radiotherapy directed to the head/cranium only, the craniospinal axis, or the abdominopelvic region. CONCLUSION: The 3D-RT study will provide knowledge on the risk of adverse late health outcomes and radiation-associated dose-effect relationships. This information is valuable to guide follow-up care of childhood cancer survivors and to refine future treatment protocols.

Questionnaire- and linkage-based outcomes in Dutch childhood cancer survivors: Methodology of the DCCSS LATER study part 1.

BACKGROUND: Childhood cancer survivors are at risk for developing long-term adverse health outcomes. To identify the risk of and risk factors for specific health outcomes, well-established cohorts are needed with detailed information on childhood cancer diagnosis, treatment, and health outcomes. We describe the design, methodology, characteristics, and data availability of the Dutch Childhood Cancer Survivor Study LATER cohort (1963-2001) part 1; questionnaire and linkage studies. METHODS: The LATER cohort includes 5-year childhood cancer survivors, diagnosed in the period 1963-2001, and before the age of 18 in any of the seven former pediatric oncology centers in the Netherlands. Information on health outcomes from survivors and invited siblings of survivors was collected by questionnaires and linkages to medical registries. RESULTS: In total, 6165 survivors were included in the LATER cohort. Extensive data on diagnosis and treatment have been collected. Information on a variety of health outcomes has been ascertained by the LATER questionnaire study and linkages with several registries for subsequent tumors, health care use, and hospitalizations. CONCLUSION: Research with data of the LATER cohort will provide new insights into risks of and risk factors for long-term health outcomes. This can enhance risk stratification for childhood cancer survivors and inform surveillance guidelines and development of interventions to prevent (the impact of) long-term adverse health outcomes. The data collected will be a solid baseline foundation for future follow-up studies.

Prevalence and Risk Factors for Hyposalivation and Xerostomia in Childhood Cancer Survivors Following Different Treatment Modalities-A Dutch Childhood Cancer Survivor Study Late Effects 2 Clinical Study (DCCSS LATER 2).

Background: Limited data are available on the risk factors of salivary gland dysfunction in long-term childhood cancer survivors (CCS). The objective of this cross-sectional study, part of the multidisciplinary multicenter Dutch CCS Study Late Effects 2 (DCCSS LATER 2), was to assess the prevalence of and risk factors for hyposalivation and xerostomia in CCS. Methods: From February 2016 until March 2020, 292 CCS were included. Data with regard to gender, age at study, diagnosis, age at diagnosis, and treatment characteristics were collected, as well as the unstimulated (UWS) and stimulated whole salivary flow rate (SWS). Xerostomia was assessed with the Xerostomia Inventory (XI) questionnaire. Multivariable Poisson regression analyses were used to evaluate the association between potential risk factors and the occurrence of hyposalivation. Results: The minimum time between diagnosis and study enrollment was 15 years. The prevalence of hyposalivation was 32% and the prevalence of xerostomia was 9.4%. Hyposalivation and xerostomia were not significantly correlated. Risk factors for hyposalivation were female gender and a higher dose of radiotherapy (>12 Gy) to the salivary gland region. Conclusion: Considering the importance of saliva for oral health, screening for hyposalivation in CCS is suggested in order to provide optimal oral supportive care aimed to improve oral health.

Development and Validation of a Breast Cancer Risk Prediction Model for Childhood Cancer Survivors Treated With Chest Radiation: A Report From the Childhood Cancer Survivor Study and the Dutch Hodgkin Late Effects and LATER Cohorts.

PURPOSE: Women treated with chest radiation for childhood cancer have one of the highest risks of breast cancer. Models producing personalized breast cancer risk estimates applicable to this population do not exist. We sought to develop and validate a breast cancer risk prediction model for childhood cancer survivors treated with chest radiation incorporating treatment-related factors, family history, and reproductive factors. METHODS: Analyses were based on multinational cohorts of female 5-year survivors of cancer diagnosed younger than age 21 years and treated with chest radiation. Model derivation was based on 1,120 participants in the Childhood Cancer Survivor Study diagnosed between 1970 and 1986, with median attained age 42 years (range 20-64) and 242 with breast cancer. Model validation included 1,027 participants from three cohorts, with median age 32 years (range 20-66) and 105 with breast cancer. RESULTS: The model included current age, chest radiation field, whether chest radiation was delivered within 1 year of menarche, anthracycline exposure, age at menopause, and history of a first-degree relative with breast cancer. Ten-year risk estimates ranged from 2% to 23% for 30-year-old women (area under the curve, 0.63; 95% CI, 0.50 to 0.73) and from 5% to 34% for 40-year-old women (area under the curve, 0.67; 95% CI, 0.54 to 0.84). The highest risks were among premenopausal women older than age 40 years treated with mantle field radiation within a year of menarche who had a first-degree relative with breast cancer. It showed good calibration with an expected-to-observed ratio of the number of breast cancers of 0.92 (95% CI, 0.74 to 1.16). CONCLUSION: Breast cancer risk varies among childhood cancer survivors treated with chest radiation. Accurate risk prediction may aid in refining surveillance, counseling, and preventive strategies in this population.

Clinical characteristics of subsequent histologically confirmed meningiomas in long-term childhood cancer survivors: A Dutch LATER study.

BACKGROUND: Meningiomas are the most frequent brain tumours occurring after pediatric cranial radiotherapy (CrRT). Data on course of disease, to inform clinical management of meningiomas, are sparse. This study reports the clinical characteristics of histologically confirmed meningiomas in childhood cancer survivors (CCS) in the Netherlands. METHODS: In total, 6015 CCS from the Dutch Long-Term Effects After Childhood Cancer (LATER) cohort were eligible, including 1551 with prior CrRT. These CCS were diagnosed with cancer age <18 y (between 1963 and 2002) and are not subject to brain tumour screening. We identified histologically confirmed meningiomas by record linkage with the Dutch Pathology Registry (PALGA; 1991-2018), and in the Dutch LATER registry. We extracted details regarding diagnosis, treatment, and follow-up from medical records. RESULTS: We described 93 CCS with meningioma, of whom 89 (95.7%) were treated with CrRT (5.7% of 1551 with prior CrRT; OR = 68). Median age at diagnosis was 31.8 y (range: 13.2-50.5). Thirty survivors (32.3%) had synchronous meningiomas; 84 (90.3%) presented with symptoms. Only 16.1% of meningioma was detected at late effects clinics. Over time, all survivors had surgery; one-third also received radiotherapy. During follow-up 38 (40.9%), survivors developed new meningiomas, 22(23.7%) recurrences and at least four died due to the meningioma. CONCLUSIONS: Histologically confirmed meningiomas after childhood cancer are mostly diagnosed with symptoms and not during routine follow-up at late effects clinics. The meningiomas occur at a median of 20-25 y younger age than incidental meningiomas, are frequently multiple and recurrence after treatment is high. It is crucial to inform CCS and healthcare providers about risk and symptoms of subsequent meningiomas.

Radiation-induced lens opacities: Epidemiological, clinical and experimental evidence, methodological issues, research gaps and strategy.

In 2011, the International Commission on Radiological Protection (ICRP) recommended reducing the occupational equivalent dose limit for the lens of the eye from 150 mSv/year to 20 mSv/year, averaged over five years, with no single year exceeding 50 mSv. With this recommendation, several important assumptions were made, such as lack of dose rate effect, classification of cataracts as a tissue reaction with a dose threshold at 0.5 Gy, and progression of minor opacities into vision-impairing cataracts. However, although new dose thresholds and occupational dose limits have been set for radiation-induced cataract, ICRP clearly states that the recommendations are chiefly based on epidemiological evidence because there are a very small number of studies that provide explicit biological and mechanistic evidence at doses under 2 Gy. Since the release of the 2011 ICRP statement, the Multidisciplinary European Low Dose Initiative (MELODI) supported in April 2019 a scientific workshop that aimed to review epidemiological, clinical and biological evidence for radiation-induced cataracts. The purpose of this article is to present and discuss recent related epidemiological and clinical studies, ophthalmic examination techniques, biological and mechanistic knowledge, and to identify research gaps, towards the implementation of a research strategy for future studies on radiation-induced lens opacities. The authors recommend particularly to study the effect of ionizing radiation on the lens in the context of the wider, systemic effects, including in the retina, brain and other organs, and as such cataract is recommended to be studied as part of larger scale programs focused on multiple radiation health effects.

Incidence of and Risk Factors for Histologically Confirmed Solid Benign Tumors Among Long-term Survivors of Childhood Cancer.

IMPORTANCE: Survivors of childhood cancer (CCSs) face risk of developing subsequent tumors. Solid benign tumors may be cancer precursors; benign tumors and cancers may share etiologic factors. However, comprehensive data on the risk for solid benign tumors are lacking. OBJECTIVE: To quantify the incidence of and treatment-related risk factors for histologically confirmed solid nonskin benign tumors among CCSs. DESIGN, SETTING, AND PARTICIPANTS: This record linkage study involves the Dutch Childhood Oncology Group-Long-Term Effects After Childhood Cancer (DCOG-LATER) cohort of 6165 individuals diagnosed with childhood cancer at younger than 18 years from January 1, 1963, through December 31, 2001, in 7 Dutch pediatric centers and who survived at least 5 years after the diagnosis. Study groups eligible for record linkage from 1990 onward included 5843 CCSs (94.8%) and 883 siblings. Benign tumors were identified from the population-based Dutch histopathology and cytopathology registry (PALGA). Follow-up was completed on May 1, 2015. Data were analyzed from January 1, 1990, through May 1, 2015. MAIN OUTCOMES AND MEASURES: Cumulative incidence of any subsequent benign tumor for cohort strata and multivariable Cox proportional hazards regression models (hazard ratios [HRs]) were used to evaluate potential risk factors for 8 major benign tumor subtypes. RESULTS: Of the 5843 eligible CCSs (55.9% male), 542 (9.3%) developed a histologically confirmed subsequent benign tumor after a median follow-up of 22.7 years (range, 5.0-52.2 years). Among women, abdominopelvic radiotherapy inferred dose-dependent increased risks for uterine leiomyoma (n = 43) for doses of less than 20 Gy (HR, 1.9; 95% CI, 0.5-7.0), 20 to less than 30 Gy (HR, 3.4; 95% CI, 1.1-10.4), and at least 30 Gy (HR, 5.4; 95% CI, 2.4-12.4) compared with no abdominopelvic radiotherapy (P = .002 for trend). High-dose radiotherapy to the trunk was not associated with breast fibroadenoma (n = 45). Of 23 osseous and/or chondromatous neoplasms, 16 occurred among leukemia survivors, including 11 after total body irradiation (HR, 37.4; 95% CI, 14.8-94.7). Nerve sheath tumors (n = 55) were associated with radiotherapy (HR at 31 years of age, 2.9; 95% CI, 1.5-5.5) and a crude indicator of neurofibromatosis type 1 or 2 status (HR, 5.6; 95% CI, 2.3-13.7). Subsequent risk for benign tumors was higher than the risks for subsequent nonskin solid malignant neoplasms and for benign tumors among siblings. CONCLUSIONS AND RELEVANCE: This record linkage study uses a unique resource for valid and complete outcome assessment and shows that CCSs have an approximately 2-fold risk of developing subsequent benign tumors compared with siblings. Site-specific new findings, including for uterine leiomyoma, osteochondroma, and nervous system tumors, are important to enable early diagnosis; this information will be the first step for future surveillance guidelines that include some benign tumors in CCSs and will provide leads for in-depth etiologic studies.

Long-Term Risk of Skin Cancer Among Childhood Cancer Survivors: A DCOG-LATER Cohort Study.

BACKGROUND: Skin cancer is common after radiotherapy among childhood cancer survivors (CCSs). We studied risks and risk factors for subsequent skin cancers, with emphasis on radiation dose, exposed skin surface area, and chemotherapeutic agents. METHODS: The DCOG-LATER cohort study includes 5-year Dutch CCSs diagnosed 1963-2001. Subsequent skin cancers were identified from record linkages with the Netherlands Cancer Registry and Dutch Pathology Registry. Incidence rates were compared with general population rates. Multivariable Cox regression models were used, applying a novel method of case-control sampling enabling use of tumor location in cohort analyses. All statistical tests were two-sided. RESULTS: Among 5843 CCSs, 259 developed 1061 basal cell carcinomas (BCCs) (standardized incidence ratio [SIR] = 29.8, 95% confidence interval [CI] = 26.3 to 33.6; excess absolute risk per 10 000 person-years (EAR) = 24.6), 20 had melanoma (SIR = 2.3, 95% CI = 1.4 to 3.5; EAR = 1.1), and 10 had squamous cell carcinoma (SIR = 7.5, 95% CI = 3.6 to 13.8; EAR = 0.8). Cumulative incidence of BCC 40 years after childhood cancer was 19.1% (95% CI = 16.6 to 21.8%) after radiotherapy vs 0.6% expected based on general population rates. After a first BCC, 46.7% had more BCCs later. BCC risk was associated with any radiotherapy to the skin compartment of interest (hazard ratio [HR] = 14.32, 95% CI = 10.10 to 20.29) and with estimated percentage in-field skin surface area (26-75%: HR = 1.99, 95% CI = 1.24 to 3.20; 76-100%: HR = 2.16, 95% CI = 1.33 to 3.53, vs 1-25% exposed; Ptrend among exposed = .002), but not with prescribed radiation dose and likelihood of sun-exposed skin-area. Of all chemotherapy groups examined, only vinca alkaloids increased BCC risk (HR = 1.54, 95% CI = 1.04 to 2.27). CONCLUSION: CCSs have a strongly, 30-fold increased BCC risk. BCC risk appears to increase with increasing skin surface area exposed. This knowledge underscores the need for awareness by survivors and their health care providers.

Risk of benign meningioma after childhood cancer in the DCOG-LATER cohort: contributions of radiation dose, exposed cranial volume, and age.

BACKGROUND: Pediatric cranial radiotherapy (CrRT) markedly increases risk of meningiomas. We studied meningioma risk factors with emphasis on independent and joint effects of CrRT dose, exposed cranial volume, exposure age, and chemotherapy. METHODS: The Dutch Cancer Oncology Group-Long-Term Effects after Childhood Cancer (DCOG-LATER) cohort includes 5-year childhood cancer survivors (CCSs) whose cancers were diagnosed in 1963-2001. Histologically confirmed benign meningiomas were identified from the population-based Dutch Pathology Registry (PALGA; 1990-2015). We calculated cumulative meningioma incidence and used multivariable Cox regression and linear excess relative risk (ERR) modeling. RESULTS: Among 5843 CCSs (median follow-up: 23.3 y, range: 5.0-52.2 y), 97 developed a benign meningioma, including 80 after full- and 14 after partial-volume CrRT. Compared with CrRT doses of 1-19 Gy, no CrRT was associated with a low meningioma risk (hazard ratio [HR] = 0.04, 95% CI: 0.01-0.15), while increased risks were observed for CrRT doses of 20-39 Gy (HR = 1.66, 95% CI: 0.83-3.33) and 40+ Gy (HR = 2.81, 95% CI: 1.30-6.08). CCSs whose cancers were diagnosed before age 5 versus 10-17 years showed significantly increased risks (HR = 2.38, 95% CI: 1.39-4.07). In this dose-adjusted model, volume was not significantly associated with increased risk (HR full vs partial = 1.66, 95% CI: 0.86-3.22). Overall, the ERR/Gy was 0.30 (95% CI: 0.03-unknown). Dose effects did not vary significantly according to exposure age or CrRT volume. Cumulative incidence after any CrRT was 12.4% (95% CI: 9.8%-15.2%) 40 years after primary cancer diagnosis. Among chemotherapy agents (including methotrexate and cisplatin), only carboplatin (HR = 3.55, 95% CI: 1.62-7.78) appeared associated with meningioma risk. However, we saw no carboplatin dose-response and all 9 exposed cases had high-dose CrRT. CONCLUSION: After CrRT 1 in 8 survivors developed late meningioma by age 40 years, associated with radiation dose and exposure age, relevant for future treatment protocols and awareness among survivors and physicians.

Colorectal Adenomas and Cancers After Childhood Cancer Treatment: A DCOG-LATER Record Linkage Study.

Background: Although colorectal adenomas serve as prime target for colorectal cancer (CRC) surveillance in other high-risk groups, data on adenoma risk after childhood cancer are lacking. We evaluated the risk of histologically confirmed colorectal adenomas among childhood cancer survivors. A secondary aim was to assess CRC risk. Methods: The DCOG-LATER cohort study includes five-year Dutch childhood cancer survivors and a sibling comparison group (n = 883). Colorectal tumors were identified from the population-based Dutch Pathology Registry (PALGA). We calculated cumulative incidences of adenomas/CRCs for survivors and siblings. For adenomas, multivariable Cox regression models were used to evaluate potential risk factors. All statistical tests were two-sided. Results: Among 5843 five-year survivors (median follow-up = 24.9 years), 78 individuals developed an adenoma. Cumulative incidence by age 45 years was 3.6% (95% confidence interval [CI] = 2.2% to 5.6%) after abdominopelvic radiotherapy (AP-RT; 49 cases) vs 2.0% (95% CI = 1.3% to 2.8%) among survivors without AP-RT (28 cases; Pdifference = .07) and vs 1.0% (95% CI = 0.3% to 2.6%) among siblings (6 cases) (Pdifference = .03). Factors associated with adenoma risk were AP-RT (hazard ratio [HR] = 2.12, 95% CI = 1.24 to 3.60), total body irradiation (TBI; HR = 10.55, 95% CI = 5.20 to 21.42), cisplatin (HR = 2.13; 95% CI = 0.74 to 6.07 for <480 mg/m²; HR = 3.85, 95% CI = 1.45 to 10.26 for ≥480 mg/m²; Ptrend = .62), a hepatoblastoma diagnosis (HR = 27.12, 95% CI = 8.80 to 83.58), and family history of early-onset CRC (HR = 20.46, 95% CI = 8.10 to 51.70). Procarbazine was statistically significantly associated among survivors without AP-RT/TBI (HR = 2.71, 95% CI = 1.28 to 5.74). Thirteen CRCs occurred. Conclusion: We provide evidence for excess risk of colorectal adenomas and CRCs among childhood cancer survivors. Adenoma risk factors include AP-RT, TBI, cisplatin, and procarbazine. Hepatoblastoma (familial adenomatous polyposis-associated) and family history of early-onset CRC were confirmed as strong risk factors. A full benefit-vs-harm evaluation of CRC screening among high-risk childhood cancer survivors warrants consideration.