Now, a simple test will tell if breast cancer is likely to return
A simple blood test could predict if the most common form of breast cancer will come back after treatment, scientists suggest.
By providing an early warning the technique would spare some women unnecessary treatment with gruelling anti-cancer drugs.
"If we can accurately predict which women are at high risk of breast cancer recurrence, it gives the physicians and oncologists treating these women time to design a more aggressive therapy in the hopes of preventing the cancer from coming back," the Daily Mail quoted researcher Sambasivarao Damaraju as saying.
"Treatment strategies could be tailor-made for these women based on their genetic make-up and how susceptible it makes them to breast cancer recurrence," Damaraju said.
The kit, which is being developed in Canada, focuses on something called luminal A breast cancer - the most common form of the disease and the type generally thought to have the best prognosis.
However, with it making up around 60 percent of the 50,000 cases of breast cancer diagnosed each year, it still accounts for a substantial number of relapses and deaths.
The University of Alberta researchers tested blood samples taken from women when they had been diagnosed with breast cancer years previously.
Comparing the DNA of samples taken from women whose cancer had returned with DNA of samples from women who had remained in remission flagged up genetic changes linked to the cancer coming back.
Other predictor tests in development use the genes from the cancer itself. But the Canadian researchers believe their technique will be more accurate, as it uses the DNA a person is born with to work out if they have a predisposition to breast cancer recurring.
It is hoped that in future, the test could be used alongside traditional microscopic techniques to improve the way breast cancer patients are treated.