Genetics may determine cancer risk

ADVANCES IN research mean a person's risk of developing breast cancer may be categorised in relation to their genetic make-up in the near future, a major international conference heard in Galway at the weekend.

Professor of surgery at NUI Galway, Michael Kerin said breast cancer therapy was entering a new era of individualised, patient-centred care.

"Each cancer has particular characteristics requiring individual approaches to therapy whether it is local surgery, radiotherapy or newer biological targeted treatment.

"Some particular cancers pose major difficulties for diagnosis and some occur in patients who have a genetic predisposition or family history," he explained.

Prof Kerin was speaking on Genetic predisposition in breast cancer: improved understanding of risk at the three-day inaugural international breast cancer conference at NUI Galway.

The conference was held by the department of surgery at NUIG in conjunction with the Nottingham series of meetings which, for the past 20 years, has been the most influential breast cancer meeting in Britain and Ireland.

The event, which will be held from now on on alternate years in Galway and Nottingham, was attended by leaders in cancer management from Ireland and around the world.

Prof Kerin said understanding genetic predisposition to breast cancer had improved greatly and it was now known that a person with an abnormality in the high-penetrance BCRA gene had an 80 per cent lifetime risk of getting breast cancer.

He said scientists were now looking for new genes such as SNiP (Single Nucleotide Polymorphism) which may increase the risk of getting breast cancer by one and a half times.

"We are getting to the stage where we will be able to categorise risk of developing breast cancer in relation to genetic make-up. This will allow us to respond with different treatments and to individualise treatment," he said.

Prof Roger Blamey, emeritus professor (surgery) and consultant surgeon at Nottingham University Hospitals NHS Trust, delivered the Fred Given keynote lecture on Lifetime Experience of Breast Cancer Management: Changing Times.

He said that in the 1970s there was very little patient awareness around breast cancer, no ultrasound and only poorly read mammograms and a wait of up to a year for surgery which involved a radical mastectomy followed by radiotherapy.

"Only 20 per cent of patients were alive after 20 years so not only were they being grossly overtreated with horrible side effects, the treatment was not curative," he said.

Since then, Prof Blamey explained, not only had awareness and diagnostics improved, treatments had vastly improved and Tamoxifen and hormone treatments had been introduced.

"This meant that by the 1990s, there were lots of improvements in place. There were breast cancer specialists working in Ireland with clinics and screening in place. Pathology had also greatly improved and there was better understanding of the disease and, therefore, better prognostic prediction and quality of life."

Prof Blamey said a person's chance of dying from breast cancer after 10 years halved between the 1980s and 1990s and he believes treatment was responsible for much of this drop with screening having a lower impact.

The biggest recent advance in breast cancer research is the recognition that women with the high-risk genes BRCA 1 and 2 are predisposed to breast cancer. However, he did not believe testing should take place at random although people can pay to have genes tested at about €2,500 per gene.