It was already known that men carrying the BRCA2 mutation were at greater risk of prostate cancer. But research published in the Journal of Clinical Oncology shows that the cancers spread faster and are more often fatal in these patients.
As it can be difficult for doctors to determine whether newly diagnosed prostate cancer will be life-threatening, many patients are currently put under 'active surveillance' rather than put forward for immediate treatment.
'It is clear from our study that prostate cancers linked to inheritance of the BRCA2 cancer gene are more deadly than other types', she said. 'It must make sense to start offering affected men immediate surgery or radiotherapy, even for early-stage cases that would otherwise be classified as low-risk'.
Around one percent of prostate cancer patients will have the BRCA2 mutation. Professor Eeles admits that without clinical trials it is impossible to be sure that this group of men would benefit from earlier treatment. All the same, she says, 'the hope is that our study will ultimately save lives by directing treatment at those who most need it'.
In the study researchers examined the medical records of 61 prostate cancer patients carrying the BRCA2 mutation as well as 18 patients with the related BRCA1 mutation and 1,940 non-carriers.
They found that when they received the diagnosis, men with either mutation were significantly more likely to have advanced stage cancer, or cancer that had already spread, than other patients. Crucially, patients with BRCA2 mutations were significantly less likely to survive the cancer, living an average of six and a half years after diagnosis compared with nearly 13 years for non-carriers. BRCA1 carriers also had reduced survival time, but this was not statistically significant.
Professor Alan Ashworth, chief executive of the ICR, said that the study illustrated how 'knowledge of cancer genetics is now increasingly shaping the way we treat the disease, by allowing us to offer more intensive treatment, or even different drugs altogether, for people who have inherited cancer genes'.
The study was a UK Clinical Research Network portfolio study, funded by the Ronald and Rita McAulay Foundation and Cancer Research UK.