Twin studies have shown that approximately one third of all breast cancers have an inherited component. Only some few percent are explained by BRCA1 and BRCA2 mutations. For the remaining approximately 60-70% of breast cancers the genetic component is of course still influential but interaction with certain lifestyle factors are more important than for the familial cases.
Genetic determinants of postmenopausal breast cancer
In this study, we used a case-control study established in the 90s consisting of approximately 3,000 women with postmenopausal breast cancer and an equivalent number of age-matched healthy controls. For approximately 50% of these patients we were able to gather biological samples. A large number of studies have been conducted initially mainly focusing on oestrogen metabolising genes. In 2003 we teamed up with Genome Institute of Singapore and Dr. Jianjun Liu. In 2005 we became partners of the Breast Cancer Association Consortium including some 22 groups worldwide.
The aim of the study was to identify genetic determinants of postmenopausal breast cancer and evaluate the interaction of lifestyle factors. We also looked at inheritance of prognosis using the same dataset.
This project formed the basis to what later became the Swedish participation in the COGS project. We evaluated the metabolising genes and metabolising pathway, the oestrogen receptor binding sites, p53 receptor binding sites and conducting genome-wide SNP scans for risk and prognosis of breast cancer.
Project leader: Per Hall
Project period: 2003-2009
Main financing: National Institutes of Health (NIH)
Jianju Liu, Genome Institute of Singapore, Singapore
Jingmei Li, Genome Institute of Singapore, Singapore