'Genetic signature' breakthrough in prostate cancer tests

In order to develop a new DNA test that can identify men at high risk of recurring prostate cancer, scientists analysed biopsy tissue samples taken from 126 treated men with the disease who were thought to be at intermediate risk of their cancer returning.

• Researchers then looked at each patient's whole genetic code, searching for missing, extra, or irregular sections of DNA so they could identify signature patterns linked to a high or low risk of recurring cancer

• The test was used to predict outcomes for a second group of 150 patients who had their prostate tumours removed by surgery.
• A secondary study found that tumours affected by hypoxia - starved of oxygen - were most associated with worse survival

• Men with low levels of genetic changes and low hypoxia had the best outcomes, with 93% lasting five years without their cancer recurring
• Only 49% of men with high levels of genetic alterations and high hypoxia escaped a cancer recurrence for five years.

A new DNA test can identify men at high risk of recurring prostate cancer with almost 80% accuracy, say scientists.

The biopsy test singles out patients likely to relapse after surgery or radiotherapy by looking for specific genetic changes at 100 sites in DNA.

Researchers from the University of Toronto, Canada, believe the "genetic signature" test will help doctors determine which patients need extra help after initial treatment.

Professor Robert Bristow, lead scientist, said: "Existing methods for identifying high risk patients are imperfect, so new tests are required that are better at predicting which patients will have their cancer recur.

"These men can then be offered additional treatments, such as chemo and hormone therapy, that will combat the prostate cancer throughout their entire body, rather than therapies solely focused on the prostate, in order to improve their chances of survival.

"This is the first report of a test using information derived from biopsy samples that can predict with close to 80% accuracy which men are at high or low risk of their prostate cancer recurring."