Importance of updating family cancer history in childhood cancer survivors.

Estimates of the number of childhood cancers with a genetic basis range from 5-8.5% found in germline samples to 29% based on clinical criteria. Family history-taking practice is a fundamental first step in detecting at risk individuals and families. This study focused on Li-Fraumeni Syndrome (LFS), a highly penetrant cancer syndrome. Reported family history in a cohort of 648 of cancer survivor cohort (CCS) was examined. Eligible CCS were: (i) aged up to 14 years at diagnosis; (ii) more than 5 years postdiagnosis; (iii) treated for a childhood cancer at the study hospitals in NSW, Australia; (iv) in remission for more than 3 years. CCS completed self-administered questionnaires. Medical records confirmed diagnosis and treatment-related information. Our findings reveal an increased cancer risk among sibling and relatives of CCS. 91% of siblings diagnosed with cancer were diagnosed under the age of 40 and about 30% diagnosed under the aged of 15 revealing a 5- (RR = 5.1; 95% CI, 3.3-7.9) and 44-fold (RR = 44.6; 95% CI, 18.4-108.3) increased risked of cancer compared with the Australian population, respectively. About 2% of CCS reported that they had been diagnosed with a genetic cancer syndrome. However, 11% of survivors described a family history pattern which met Chompret criteria for screening for TP53 mutations associated with LFS. Our data suggests that familial cancer predispositions may be initially overlooked. Aperiodic and accurate ascertainment of family cancer history of childhood cancer patients and survivors is therefore recommended.