Annals of Oncology Advance Access originally published online on July 24, 2008
Annals of Oncology 2008 19(12):2084-2088; doi:10.1093/annonc/mdn527
epidemiology |
Age of onset in familial cancer
1 Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), Heidelberg, Germany
2 Center for Family and Community Medicine, Karolinska Institute, Huddinge, Sweden
* Correspondence to: A. Brandt Dipl. Math., Division of Molecular Genetic Epidemiology, German Cancer Research Centre (DKFZ), Im Neuenheimer Feld 580, Heidelberg, Germany. Tel: +49-6221-421805; Fax: +49-6221-421810; E-mail: andreas.brandt{at}dkfz.de
Background: Reliable estimates on the age of onset between familial and sporadic cancers are important for etiological understanding and clinical practice. Specific studies on the age of onset of familial cancer compared with sporadic cancer are less common than studies on familial risks and these are almost lacking for rare cancers.
Materials and methods: The Swedish Family-Cancer Database was used to estimate cumulative risks of all common cancer types according to family history with a stratified Cox model based on Tsiatis method. We calculated the age at which the cumulative risk of cancer reached 0.1% and 0.5%.
Results: The age to reach a cumulative risk of 0.1% was significantly lower among individuals with a parent or a sibling affected for any of the investigated cancer sites. The age differences ranged from 2.6 years (sons of prostate cancer patients) to 16.3 years (brothers of urinary bladder cancer patients). A cumulative risk of 0.5% was also reached earlier for individuals with a family history, especially for individuals with a parent and a sibling affected.
Conclusions: Cancers in individuals with a family history occur earlier than in sporadic patients. The derived estimates may be useful for clinical counseling and screening recommendations.
Key words: age of onset, cumulative risk, familial cancer, family history, screening
Received for publication March 5, 2008. Accepted for publication June 23, 2008.