ABSTRACT
PURPOSE: Childhood cancer survivors, in particular those treated with radiation therapy, are at high risk of long-term iatrogenic events. The prediction of risk of such events is mainly based on the knowledge of the radiation dose received to healthy organs and tissues during treatment of childhood cancer diagnosed decades ago. We aimed to set up a standardized organ dose table to help former patients and clinicians in charge of long-term follow-up clinics. METHODS AND MATERIALS: We performed whole body dosimetric reconstruction for 2646 patients from 12 European countries treated between 1941 and 2006 (median, 1976). Most plannings were 2- or 3-dimensional. A total of 46% of patients were treated using Cobalt 60, and 41%, using a linear accelerator. The median prescribed dose was 27.2 Gy (IQ1-IQ3, 17.6-40.0 Gy). A patient-specific voxel-based anthropomorphic phantom with more than 200 anatomic structures or substructures delineated as a surrogate of each subject's anatomy was used. The radiation therapy was simulated with a treatment planning system based on available treatment information. The radiation dose received by any organ of the body was estimated by extending the treatment planning system dose calculation to the whole body, by type and localization of childhood cancer. RESULTS: The integral dose and normal tissue doses to most of the 23 considered organs increased between the 1950s and 1970s and decreased or plateaued thereafter. Whatever the organ considered, the type of childhood cancer explained most of the variability in organ dose. The country of treatment explained only a small part of the variability. CONCLUSIONS: The detailed dose estimates provide very useful information for former patients or clinicians who have only limited knowledge about radiation therapy protocols or techniques, but who know the type and site of childhood cancer, sex, age, and year of treatment. This will allow better prediction of the long-term risk of iatrogenic events and better referral to long-term follow-up clinics.
ABSTRACT
BACKGROUND: Optic pathway gliomas (OPGs) represent 5% of childhood brain tumors. Successive relapses lead to multiple treatments exposing to late complications. METHODS: We included patients treated at Gustave Roussy (GR) between January 1980 and December 2015 for OPG, before 18 years old and alive at 5 years from diagnosis. Mortality and physical health conditions data were extracted from medical data files and updated, thanks to the GR long-term follow-up program and French national mortality registry for patients included in the French Childhood Cancer Survivor Study. RESULTS: We included 182 5-year OPG-childhood survivors in the analysis (sex ratio M/F 0.8, 35% with neurofibromatosis type 1 [NF1]). With a median follow-up of 17.2 years (rangeâ =â 5-41), we registered 82 relapses, 9 second malignancies, and 15 deaths as first events after 5 years, resulting in 20-year conditional overall survival (C-OS) and late events-free survival of 79.9% (95% confidence interval [CI]â =â 71-86) and 43.5% (95% CIâ =â 36-51), respectively. Radiotherapy exposure in NF1 patients (hazard ratio [HR] = 6, 95% CI = 1.7-21.2) and hypothalamic involvement (HR = 3.2, 95% CI = 1.4-7.3) were significantly associated with C-OS in multivariable analyses. Ninety-five percent of 5-year OPG survivors suffered from any health condition, especially visual acuity "<1/10" (nâ =â 109), pituitary deficiency (nâ =â 106), and neurocognitive impairment (nâ =â 89). NF1 (HR 2.1) was associated with precocious puberty. With a median time post-diagnosis of 4.2 years, 33 cerebrovascular events were observed in 21 patients. CONCLUSIONS: Late relapses, second malignancies, and cerebrovascular diseases are severe late events resulting in premature mortality. Morbidity is high and needs after-cancer care to improve quality of life. Risk factors could be considered to better stratify long-term follow-up.
Subject(s)
Optic Nerve Glioma , Humans , Male , Female , Optic Nerve Glioma/pathology , Optic Nerve Glioma/therapy , Child , Child, Preschool , Adolescent , Longitudinal Studies , Follow-Up Studies , Survival Rate , Cancer Survivors/statistics & numerical data , Infant , Neoplasm Recurrence, Local/pathology , Neoplasm Recurrence, Local/epidemiology , Prognosis , Adult , Neurofibromatosis 1/therapy , Neurofibromatosis 1/complications , Neurofibromatosis 1/mortality , Neurofibromatosis 1/pathology , Infant, NewbornABSTRACT
Background: Childhood cancer survivors (CCS) are at an elevated risk of developing both a second malignant neoplasm (SMN) and cardiac disease. Objectives: This study sought to assess the excess of occurrence of cardiac disease after a SMN among CCS. Methods: Analyses included 7,670 CCS from the French Childhood Cancer Survivors Study cohort diagnosed between 1945 and 2000. To account for the time dependence of the occurrence of a SMN, we employed a landmark approach, considering an additive regression model for the cumulative incidence of cardiac disease. We estimated the effect of a SMN on the instantaneous risk of cardiac disease using a proportional cause-specific hazard model, considering a SMN as a time-dependent exposure. In both models, we adjusted for demographic and treatment information and considered death as a competing event. Results: In 7,670 CCS over a median follow-up of 30 years (IQR: 22-38 years), there were 378 cases of cardiac disease identified, of which 49 patients experienced a SMN. Patients who survived 25 years after their childhood cancer diagnosis and had a SMN in that time frame had a significantly increased cumulative incidence of cardiac disease, which was 3.8% (95% CI: 0.5% to 7.1%) higher compared with those without a SMN during this period. No SMN-induced excess of cardiac disease was observed at subsequent landmark times. SMNs were associated with a 2-fold increase (cause-specific HR: 2.0; 95% CI: 1.4-2.8) of cardiac disease. Conclusions: The occurrence of a SMN among CCS is associated with an increased risk of cardiac disease occurrence and risk at younger ages.