Steliarova-Foucher E, et al. - Researchers analyzed cancer incidence trends at ages 0–19 years in Europe from 1991–2010 by using a large database representing 1·3 billion person-years over this time period. An increase in incidence was reported, which could be partly attributable to improvements in the diagnosis and registration of cancers over time, although some changes in underlying putative risk factors cannot be excluded. The findings call for continued monitoring in young population at an international level.

Methods

• For this population-based registry study, all population-based cancer registries operating in European countries were invited to participate.
• Individual records of cancer cases were listed, including sex, age, date of birth, date of cancer diagnosis, tumour sequence number, primary site, morphology, behaviour, and the most valid basis of diagnosis.
• They also requested population counts in each calendar year by sex and age for the registration area, from official national sources, and specific information regarding the covered area and registration practices.
• To become a contributor, an eligible registry was required to provide quality data for all complete calendar years in the period 1991–2010.
• For all cancers and major diagnostic groups, they assessed incidence rates and the average annual percentage change with 95% CIs, by region and overall, separately for children (age 0–14 years) and adolescents (age 15–19 years).
• Using joinpoint analyses, they assessed and quantified the stability of the trends.

Results

• For the years 1991–2010, a total of 180,335 unique cases were contributed by 53 registries in 19 countries.
• A total of 15,162 (8·4%) of 180,335 cases were excluded due to differing practices of registration, and the quality indicators for the 165,173 cases included were considered to be satisfactory.
• As per data, the estimated average annual age-standardised incidence was 137·5 (95% CI 136·7–138·3) per million person-years.
• With no change in trend, a significant increase in incidence ie, by 0·54% (0·44–0·65) per year was observed in children (age 0–14 years).
• On the basis of all 35,138 eligible cases, the estimated combined European incidence was 176·2 (174·4–178·0) per million person-years in adolescents; this increased significantly by 0·96% (0·73–1·19) per year, although a deceleration in this increasing trend was indicated by recent changes in rates among adolescents.
• By age group, geographical region, and diagnostic group, temporal variations in trends were observed.
• Findings revealed that 46·9 (46·5–47·3) per million person-years was the estimated combined age-standardised incidence of leukaemia based on 48,458 cases in children; this increased significantly by 0·66% (0·48–0·84) per year.
• Based on 4702 cases, 23·6 (22·9–24·3) per million person-years was reported as the estimated average overall incidence of leukaemia in adolescents, and the average annual change was 0·93% (0·49–1·37).
• They also observed increasing incidence of lymphoma in adolescents (average annual change 1·04% [0·65–1·44], malignant CNS tumours in children (average annual change 0·49% [0·20–0·77]), and other tumours in both children (average annual change 0·56 [0·40–0·72]) and adolescents (average annual change 1·17 [0·82–1·53]).