Background: Since 2004 mass screening (MS) for neuroblastoma at 6 months of age in Japan has been halted. The clinical features of neuroblastoma before and after the cessation of MS were compared to evaluate the significance of MS.
Methods: Patients with neuroblastoma under the age of 6 were divided into 2 groups. The group A (post-MS cohort) was consisted with 402 patients enrolled into the registry of the Japanese Society of Pediatric Surgeons (JSPS) between 2005 and 2009, and the group B (MS cohort; Hiyama et al. Lancet, 2008) with 1,797 patients registered with the Japanese MS study group between 1990 and 1998. The age at diagnosis, clinical stage defined according to the JSPS staging system that were identical to Evans’ staging system and cumulative incidence of neuroblastoma indicated by the number of patients per 100,000 births were compared between the 2 groups.
Results: There was a significant decrease in the incidence of patients 6-11 months of age (9.99, group A; 128.53, group B) and a significant increase in the incidence of patients 2-5 years of age (27.01, group A; 8.00, group B) after the cessation of MS. The number of the patients with stage IV disease increased significantly after the cessation of MS (32.00, group A; 20.24, group B). In stage IV patients, there was a significant decrease in the incidence of patients 6-11 months of age (3.33, group A; 7.73, group B) and a significant increase in the incidence of patients 2-5 years of age (18.31, group A; 5.24, group B) after the cessation of MS.
Conclusion: The incidence of neuroblastoma patients between the age of two and five-years old with stage IV high-risk disease significantly increased after the cessation of MS.