25 January 2016
ByAppeared in BioNews 836
The researchers analysed data from 3236 women diagnosed with epithelial ovarian cancer (EOC), 2000 women with a family history of the disease and 3431 women without cancer.
'Our work has found a valuable piece of the puzzle behind ovarian cancer, and we hope that [it] could eventually form the basis of a genetic test to identify women at greatest risk,' said study author Professor Paul Pharoah of the University of Cambridge. 'Finding these women will help us prevent more cancers and save lives. This would be important in a disease like ovarian cancer, which tends to be diagnosed at a late stage when the chances of survival are worse.'
The study was published in the Journal of the National Cancer Institute. In the UK around 7100 women are diagnosed with EOC, and over 4200 women die from the disease each year. This large-scale risk-prediction study identified a new gene mutation that could be incorporated into clinical genomic screening.
For women with the BRIP1 mutation, their lifetime risk is tripled, but only one in 1000 women in the UK is estimated to have the mutation. Women without this mutation have a 1.8 percent chance of developing ovarian cancer during their lifetime, but for women with the BRIP1 mutation this increases to 5.8 percent. This is classed as a 'moderate increase in risk' by the study authors. Other mutations, such as the BRCA1 mutation (involved in breast and ovarian cancer), are known to cause a 40 to 50 percent increase in risk. The study included only European women, so its findings can't be extrapolated to women of other ancestries.
The researchers also found that women with the BRIP1 mutation were at higher risk of aggressive cancer, diagnosed at a later stage and at an older age. These factors all result in a poor prognosis for the patient. BRIP1 could therefore be an important gene for clinical screening. Currently, genetic tests are available to women who are likely to have a BRCA1 or BRCA2 mutation.
Some experts question the benefits of screening for BRIP1 mutations. In an editorial accompanying the journal article, Dr Judith Balmaña and Dr Susan Domchek write: 'As risks of developing BRIP1-associated ovarian cancer are moderate and developing breast cancer uncertain, the risk/benefit profile and timing of oophorectomy [preventative surgery] are different than for BRCA1/2, and we should not 'default' to oophorectomy at age 40 years.'