Test that can pinpoint recurring breast cancer

THE types of breast cancer that are most likely to return after treatment could be identified by a new test.

Scientists have identified genetic variants that generally only occur in relapsing cancers. Spotting them at diagnosis could help doctors deliver treatments tailored to at-risk patients. Dr Lucy Yates, from the Wellcome Trust Sanger Institute in Hinxton, Cambs, said: “We have found that some of the genetic mutations that drive breast cancers that relapse are relatively uncommon amongst cancers that do not relapse at the point of primary diagnosis.

“Some of these genetic alterations are potentially targetable with drugs.” About one in five breast cancers come back after treatment, appearing either in the same place as the original tumour or spreading to other parts of the body.

The Sanger team analysed DNA from tumour samples taken from 1,000 breast cancer patients. In 161 cases samples were taken from recurring tumours or spreading (metastatic) cancers.

Cancer genes found in tumours sampled at first diagnosis were compared with those in relapsed cancers.

Within an individual cancer, a wide range of accumulating factors influencing the function and activity of genes may affect tumour survival, the study found.

Prof Peter Naredi, cochairman of the European Cancer Congress in Vienna, where the research will be presented, said: “This study also underlines the fact that we should consider a recurrence of a cancer as a new event, and select the right treatment for the recurrent tumour as opposed to just relying on information from the first occurrence.”