Genetic variants associated with ovarian and breast cancers are reported in three studies published online this week in Nature Genetics. Breast and ovarian cancer are known to share some common risk factors, and these studies identify an additional shared genetic susceptibility locus.
Simon Gayther and colleagues report a genome-wide association study for ovarian cancer. They grouped 10,283 ovarian cancer cases — about half with one type of tumour, called serous — by the four major histological subtypes, and identified two new genomic regions associated with serous ovarian cancer.
Paul Pharoah and colleagues report a genome-wide association study for ovarian cancer in 8,951 cases. They identify variants at single genomic region on chromosome 19 associated with serous ovarian cancer. This locus is near the BRCA1-interacting gene MERIT40. Mutations in the BRCA1 gene are established as a risk factor for breast as well as ovarian cancer in women. Fergus Couch and colleagues searched for genetic factors that may modify this risk, by conducting a genome-wide association study for breast cancer in 1,193 BRCA1 mutation carriers with invasive breast cancer and 1,190 healthy BRCA1 carriers, with replication in an additional 5,986 BRCA1 carriers including both healthy and breast cancer cases. They identify a single genomic region on chromosome 19 as associated with breast cancer in these high risk women as well as in a particular hormone subtype of breast cancer in the general population. This is the same genomic region that Pharoah and colleagues report as being associated with ovarian cancer.