Cancer Research UK scientists have discovered that a gene called POLQ is linked to an eight-fold risk of breast cancer returning. Developing drugs to block POLQ could increase survival and stop the cancer coming back, according to research published in OncoTarget.
Scientists based at the Cancer Research UK/MRC Gray Institute for Radiation Oncology and Biology at Oxford University, examined data from 279 patients diagnosed in the early 90s with early breast cancer.
Excessive POLQ was linked to markedly increased risk of cancer coming back.
The team confirmed these results with genetic data from several other studies of breast cancer patients amounting to more than 800 patients in the UK, the Netherlands and Sweden.
Professor Gillies McKenna, director of the Cancer Research UK/MRC Gray Institute at Oxford University, said: “This is important research which provides evidence that POLQ may be a very appealing target for drug development.
“As POLQ is not switched on by most healthy tissues it is possible that if drugs could be developed to block this gene, they would make tumours more responsive to treatments such as radiotherapy and chemotherapy but not increase the side effects caused to healthy cells.
“Drugs that block POLQ may be able to reverse the very poor survival associated with over production of this gene.”
The reason why POLQ is linked to poor survival is not yet clear, but it is possible that it causes tumour cells to be resistant to treatments such as radiotherapy which are often required to treat early breast cancer patients. It is also possible that POLQ enables tumour cells to behave in a more aggressive way than cancers that do not express the gene.
In the UK in 2007 almost 45,700 women were diagnosed with breast cancer and 20 to 25 per cent of all breast cancer cases are oestrogen negative – between 10,000 to 11,500 new cases a year.
Dr Lesley Walker, Cancer Research UK’s director of science information, said: “Fundamental scientific research like this to examine the genetic causes for breast cancer provides us with the foundations to develop new exciting drugs to beat this disease and increase survival in the future.”
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Overexpression of POLQ Confers a Poor Prognosis in Early Breast Cancer Patients
Geoff S Higginset al. OncoTargets. http://impactjournals.com/oncotarget/advance.html
About breast cancer
• Female breast cancer incidence rates have increased by around 50% over the last twenty-five years.
• In the last ten years, female breast cancer incidence rates in the UK have increased by 5%.
• 8 in 10 breast cancers are diagnosed in women aged 50 and over.
• In the UK in 2007/2008 the NHS breast screening programmes detected more than 16,000 cases of breast cancer.
• The NHS breast screening programme in England saves an estimated 1,400 lives each year.