Objective: To examine the recent incidences and trends of childhood malignant solid tumors in Shanghai.
Method: Data from the population-based Shanghai Cancer Registry and related retrospective survey were used to analyze the patterns of incidence and trends of malignant solid tumors diagnosed between 2002 and 2010 in children aged 0-14 years. The distributions of incidences were described according to gender, age and cancer types which were classified according to International Classification of Childhood Cancer (ICCC). Annual age-standardized rates (ASRs) were adjusted by the world standard population. Approximate confidence intervals for standardized rate ratios (SRR) based Poisson distribution test-based methods were used to assess changes in incidence over the period 2002 - 2006 and 2007 - 2010.
Result: (1)A total of 868 cases of childhood malignant solid tumors were diagnosed in Shanghai during 2002 - 2010, accounting for 65.8% of all childhood cancers. The ASR of 2002 - 2010 was 80.2 per million for all solid tumors. (2) The ASR was higher in boys (86.3 per million) than in girls (73.8 per million) with SRR 1.2 (95%CI 1.0 - 1.3). Incidence rate was the highest in the first five years of life with 93.4 per million. The age-specific incidence rates in 5 - 9 and 10 - 14 age groups were 65.2 and 79.3 per million, respectively. (3) CNS tumors, lymphomas, germ cell tumors, neuroblastoma, and soft tissue sarcomas were the top 5 most common solid tumors in children, with the incidence rate of 23.8, 11.0, 7.8, 7.7 and 6.8 per million, respectively. The patterns of subgroups varied in different age groups. Blastomas, such as neuroblastoma, retinoblastoma, were more common in the children aged 0 - 4 years, whereas epithelial carcinomas and bone tumors developed more frequently in elder children aged 10 - 14 years. (4) Compared with the ASR in 2002 - 2006, the ASR for both genders in 2007 - 2010 had no substantial changes (78.7 per million in 2002 - 2006 and 82.9 per million in 2007 - 2010). However, among boys, the incidence rate in 2007 - 2010 was significantly higher than that in 2002 - 2006 with SRR 1.2 (95%CI: 1.0 - 1.4). For specific subgroups of cancer, there were no substantial changes. Some cautions should be taken when interpreting results involving a small number of cases per year and those with wide 95% confidence intervals.
Conclusion: The incidence rate of pediatric malignant solid tumors among males was higher than females during 2002 - 2010, and it differed among different age groups with the highest in the first five years of life. CNS tumor was the most common type of solid tumors in children. This was a unique characteristics comparing with adult reflected in disease spectrum and age of onset. The patterns of incidence and its trends for childhood malignant solid tumors in Shanghai could provide a basis for etiologic research and preventive interventions. The findings also suggest an urgent need for longer population-based surveillance to verify the pattern and changing trends.