Pilocytic astrocytomas (PA) comprise the most common childhood central nervous system (CNS) tumor. Exploiting registry-based data from Southern and Eastern Europe (SEE) and SEER, US, we opted to examine incidence, time trends, survival and tentative outcome disparities of childhood PA by sociodemographic and clinical features. Childhood PA were retrieved from 12 SEE registries (N = 552; 1983-2014) and SEER (N = 2723; 1973-2012). Age-standardized incidence rates (ASR) were estimated and survival was examined via Kaplan-Meier and Cox regression analysis. ASR of childhood PA during 1990-2012 in SEE was 4.2/10, doubling in the USA (8.2/10). Increasing trends, more prominent during earlier registration years, were recorded in both areas (SEE: +4.1 %, USA: +4.6 %, annually). Cerebellum comprised the most common location, apart from infants in whom supratentorial locations prevailed. Age at diagnosis was 1 year earlier in SEE, whereas 10-year survival was 87 % in SEE and 96 % in SEER, improving over time. Significant outcome predictors were age <1 year at diagnosis diagnosis (hazard ratio, HR [95% confidence intervals]: 3.96, [2.28-6.90]), female gender (HR: 1.38, [1.01-1.88]), residence in SEE (HR: 4.07, [2.95-5.61]) and rural areas (HR: 2.23, [1.53-3.27]), whereas non-cerebellar locations were associated with a 9- to 12-fold increase in risk of death. The first comprehensive overview of childhood PA epidemiology showed survival gains but also outcome discrepancies by geographical region and urbanization pointing to healthcare inequalities. The worse prognosis of infants and, possibly, females merits further consideration, as it might point to treatment adjustment needs, whereas expansion of systematic registration will allow interpretation of incidence variations.

No abstract

Neuroblastoma comprises the most common neoplasm during infancy (first year of life). Our study describes incidence of neuroblastoma in Southern-Eastern Europe (SEE), including - for the first time - the Nationwide Registry for Childhood Hematological Malignancies and Solid Tumors (NARECHEM-ST)/Greece, compared to the US population, while controlling for human development index (HDI). Age-adjusted incidence rates (AIR) were calculated for 1,859 childhood (0-14 years) neuroblastoma cases, retrieved from 13 collaborating SEE registries (1990-2016), and were compared to those of SEER/US (N = 3,166; 1990-2012); temporal trends were assessed using Poisson regression and Joinpoint analyses. The overall AIR was significantly lower in SEE (10.1/million) compared to SEER (11.7 per million); the difference was maximum during infancy (43.7 vs. 53.3 per million, respectively), when approximately one-third of cases were diagnosed. Incidence rates of neuroblastoma at ages <1 and 1-4 years were positively associated with HDI, whereas lower median age at diagnosis was correlated with higher overall AIR. Distribution of primary site and histology was similar in SEE and SEER. Neuroblastoma was slightly more common among males compared to females (male-to-female ratio: 1.1), mainly among SEE infants. Incidence trends decreased in infants in Slovenia, Cyprus and SEER and increased in Ukraine and Belarus. The lower incidence in SEE compared to SEER, especially in infants living in low HDI countries possibly indicates a lower level of overdiagnosis in SEE. Hence, increases in incidence rates in infancy noted in some subpopulations should be carefully monitored to avoid the unnecessary costs health impacts of tumors that could potentially spontaneously regress.

Childhood (0-14 years) lymphomas, nowadays, present a highly curable malignancy compared with other types of cancer. We used readily available cancer registration data to assess mortality and survival disparities among children residing in Southern-Eastern European (SEE) countries and those in the United States. Average age-standardized mortality rates and time trends of Hodgkin (HL) and non-Hodgkin (NHL; including Burkitt [BL]) lymphomas in 14 SEE cancer registries (1990-2014) and the Surveillance, Epidemiology, and End Results Program (SEER, United States; 1990-2012) were calculated. Survival patterns in a total of 8918 cases distinguishing also BL were assessed through Kaplan-Meier curves and multivariate Cox regression models. Variable, rather decreasing, mortality trends were noted among SEE. Rates were overall higher than that in SEER (1.02/10 ), which presented a sizeable (-4.8%, P = .0001) annual change. Additionally, remarkable survival improvements were manifested in SEER (10 years: 96%, 86%, and 90% for HL, NHL, and BL, respectively), whereas diverse, still lower, rates were noted in SEE. Non-HL was associated with a poorer outcome and an amphi-directional age-specific pattern; specifically, prognosis was inferior in children younger than 5 years than in those who are 10 to 14 years old from SEE (hazard ratio 1.58, 95% confidence interval 1.28-1.96) and superior in children who are 5 to 9 years old from SEER/United States (hazard ratio 0.63, 95% confidence interval 0.46-0.88) than in those who are 10 to 14 years old. In conclusion, higher SEE lymphoma mortality rates than those in SEER, but overall decreasing trends, were found. Despite significant survival gains among developed countries, there are still substantial geographic, disease subtype-specific, and age-specific outcome disparities pointing to persisting gaps in the implementation of new treatment modalities and indicating further research needs.

No abstract