First description of seasonality of birth and diagnosis amongst teenagers and young adults with cancer aged 15-24 years in England, 1996-2005.

Background We aimed to examine evidence for an infectious aetiology among teenagers and young adults (TYA) by analysing monthly seasonality of diagnosis and birth amongst 15–24 year olds diagnosed with cancer in England. Methods Cases of leukaemia, lymphoma and central nervous system (CNS) tumours were derived from the national TYA cancer register (1996–2005). Incidence rates (IR) and trends were assessed using Poisson regression. Seasonality of diagnosis and birth was assessed using Poisson and logistic regression respectively with cosine functions of varying periods. Results There were 6251 cases diagnosed with leukaemia (n = 1299), lymphoma (n = 3070) and CNS tumours (n = 1882), the overall IR was 92 (95% CI 89–96) per 1,000,000 15–24 year olds per year. There was significant evidence of seasonality around the time of diagnosis for Hodgkin’s lymphoma (P < 0.001) with a peak in February, and for ‘other CNS tumours’ (P = 0.010) with peaks in December and June. Birth peaks for those with ‘other Gliomas’ (Gliomas other than Astrocytoma and Ependymoma) were observed in May and November (P = 0.015). Conclusion Our novel findings support an infectious aetiological hypothesis for certain subgroups of TYA cancer in England. Further work will examine correlation with specific infections occurring around the time of birth and diagnosis within certain diagnostic groups.