'The rates of testing in this population are probably higher than what you see in other populations, but it's still nice to see the improvement and more women having the opportunity to get tested,' said Dr Ann Partridge of the Dana-Farber Cancer Institute, lead author of the study published in JAMA Oncology.
Breast cancer is the most common cancer diagnosed in women under the age of 40 in the United States. Women who have mutations in the BRCA1 or BRCA2 genes are at an increased risk of developing breast and ovarian cancer, and to have recurrent cancer following treatment.
The researchers collected data in the United States between 2006 and 2014 as part of an ongoing study into young women with breast cancer. Their analysis focused on 897 women diagnosed with cancer at age 40 or under, and their decision to undergo genetic testing up to one year after their diagnosis.
In total, across the eight years of the study, 87 percent of women involved in the study had genetic testing. Of these, 59 had a mutation at BRCA1, and 35 had a BRCA2 mutation.
Identifying these mutations can help to inform treatment options and may influence the decision to have preventative surgery. Half of those tested who did not have a mutation chose to have a bilateral mastectomy to remove both breasts, compared with 86 percent of those carrying a mutation. Carriers of the mutation were also more likely to have undergone a salpingo-oophorectomy (ovary removal) than women who were not carriers.
It is hoped that this increase in test uptake reflects greater social awareness and acceptability of testing for genetic predisposition to the disease. In 2013 the actress and director Angelina Jolie announced that she had chosen to undergo a bilateral mastectomy and reconstruction as a result of carrying the BRCA1 mutation, which is thought to have contributed to an increase in testing – both in the United States and across the world (see BioNews 722).
The authors recognise that the high uptake observed might be attributed to the high socioeconomic status of the study participants, and Dr Partridge highlighted that removing barriers to testing remained a priority for the future: 'The recommendations are to test every woman with breast cancer under 40, for sure.'
Improving genetic counselling availability across different economic groups and underrepresented minorities would ensure that more patients have access to the benefits conferred by genetic testing. 'We know we can reduce morbidity and mortality if we have the knowledge,' said Dr Jeffrey Weitzel of the City of Hope cancer centre in Duarte, California, who co-authored an editorial published alongside the study.