Researchers at Trinity College Dublin believe they have found a way to identify tumour resistance to radiotherapy.
Up to now, there has not been a way to test which patients will respond well to radiotherapy or to reduce resistance to the therapy.
Every year about 300 people in Ireland are diagnosed with cancer of the oesophagus, also known as the food pipe or gullet.
According to the Irish Cancer Society, almost twice as many men get the disease as women.
Many oesophageal cancer patients receive radiotherapy and chemotherapy to shrink their tumour before surgery, and this forms a vital part of their treatment.
While a small number respond extremely well to treatment, most are resistant to some extent. However, treatment side effects can delay surgery and worsen overall survival.
The team of scientists included specialists from TCD, St James’s Hospital, Dublin, the Coombe Women and Infant’s University Hospital, Dublin, and the University of Hull in Britain.
The scientists showed that populations of tumour cells that had higher numbers of cancer stem cells formed larger, more aggressive tumours. They also demonstrated that the stem cells were more resistant to radiation-induced cell death.
In particular, they discovered a molecule called miR-17 that is important in driving oesophageal tumour resistance to radiotherapy.
Dr Niamh Lynam-Lennon from Trinity’s department of surgery found that if a synthetic version of miR-17 was put into the resistant cells, they became more sensitive to radiation.
Using synthetic miR-17 as an addition to radiotherapy to enhance its effectiveness in patients was a “real possibility”, she said.
Dr Lynam-Lennon said some other artificial miR-molecules were being used in clinical trials for treating other diseases.
Team leader, Ussher assistant professor in translation oncology at Trinity, Dr Stephen Maher, said the work was crucial in understanding why tumours were inherently resistant to radiotherapy.
“Our findings strongly suggest that it is the cancer stem cell population that we need to destroy if treatment is going to be effective in our oesophageal cancer patients,” said Dr Maher.
The findings from the research, mainly funded by the Health Research Board over the last three years, was published in the international peer-reviewed journal, Oncotarget.