Breast cancer survival was the same in young women with and without faulty BRCA genes, according to a new study.
It suggests that although women diagnosed with breast cancer at a young age tend to have a poorer outlook, those who have BRCA gene faults aren’t less likely to survive.
The researchers say that in the future this information could help women and their doctors make informed choices about treatment.
“No other study has followed a group of patients from diagnosis over a long period of time to discover if carrying a high-risk inherited BRCA gene alters the likelihood of being cured of breast cancer,” said lead researcher Professor Diana Eccles from the University of Southampton.
The BRCA1 and BRCA2 genes usually produce molecules inside cells that help to repair DNA. But faults in these genes raise the risk of developing breast and ovarian cancers. And in women under the age of 40 diagnosed with breast cancer, a higher proportion have these faulty genes compared with older patients.
Women who have had breast cancer are also more likely to be diagnosed with the disease a second time if they carry these genetic faults, which is why some choose to have risk-reducing surgery such as removing the breasts. Few studies have looked at whether these genes are linked with lower survival in young breast cancer patients, which this research aimed to address.
The study included 2733 women from 127 hospitals in the UK who had been diagnosed with breast cancer at the age of 40 or below. They were tested for the BRCA1 or BRCA2 gene faults using a blood sample.
Patients were then followed up for an average of just over 8 years, which revealed similar survival across women in the study, regardless of their BRCA status, the researchers report in the Lancet Oncology.
Martin Ledwick, Cancer Research UK’s Head Information Nurse, said: “Although BRCA faults increase the risk of young women developing cancer, their outlook once diagnosed is no worse than that for young women with breast cancer who don’t carry the BRCA gene faults.”
The researchers say that these findings could have implications for the design of future clinical trials. Eccles added that the results could give women “more confidence and control” when making decisions about their treatment.
“Our data provides some reassurance that patients who are diagnosed with a BRCA gene fault as part of their cancer treatment journey can complete and recover from their breast cancer treatment, which is important,” she said.
“It can be difficult for some patients to decide whether or not to have risk-reducing surgery, typically double mastectomies and removal of ovaries. And our data suggest that this decision can be made, if preferred, once a woman has physically and psychologically recovered from their cancer treatment.”
Copson, E. R. et al. (2018). Germline BRCA mutation and outcome in young-onset breast cancer (POSH): a prospective cohort study. Lancet Oncology. http://dx.doi.org/10.1016/S1470-2045(17)30891-4