Cancers in the first degree relatives of children with brain tumours

We used the nationwide Swedish Family-Cancer Database with 2060 childhood b rain tumours diagnosed in the period 1958-1996 to analyse the risk of this tumour by parental cancers and in siblings of childhood brain tumour proban ds. Groups of patients were compared by calculating standardized incidence ratios (SIRs) for brain tumours in offspring. 1.3% of brain tumour patients had a parent with nervous system cancer; SIRs were 2.4 and 1.88 for diagno stic ages < 5 and < 15 years, respectively. The data showed distinct patter ns of familial risks for childhood brain tumours, the SIR was 10.26 for bra in astrocytoma given a parent with meningioma. Parental colon cancer was as sociated with offspring ependymoma (SIR 3.70), and parental salivary gland cancers with offspring medulloblastoma (SIR 13.33, but two cases only). SIR for sibling nervous system cancer from childhood brain tumour probands was 3.55 up to age 61. (C) 2000 Cancer Research Campaign.