International Group Works to Identify Genetic Characteristics of Radiation Sensitivity to Personalize Regimens

A simple blood test may allow radiation oncologists in the future to target therapy based on a patient’s unique physiology, according to a group of European scientists reporting at the 15th congress of the European CanCer Organization (ECCO 15) and the 34th congress of the European Society for Medical Oncology (ESMO 34), or ECCO 15-ESMO 34 congress, in Berlin last week.

The group led by Professor Dirk de Ruysscher studied the files of patients with hypersensitivity to radiation therapy drawn from the European Union-funded Genetic pathways for the prediction of the effect of irradiation (GENEPI) study, reported a press release from ECCO 15-ESMO 34. The study integrates data on biological material, patients and treatment specifications from more than 8,000 European patients.

“Part of this project is the establishment of a sub-database in which very rare patient characteristics are brought together with the hypothesis that their genetic traits will enable the characterization of molecular pathways related to radio-sensitivity,” said de Rysscher in the press release.

The group created a tissue bank of skin fibroblasts, whole blood, lymphocytes, plasma and lymphoblastic cell lines harvested from patients known to be hypersensitive to radiation.

In the GENEPI study, 33 patients with hypersensitivity to radiation showed either severe side effects that occurred at very low radiation doses or lasting more than four weeks after ending radiation therapy, along with severe late side effects that lasted more than 90 days after ending treatment. In the controlled study, 23 women and 10 men were identified as highly hypersensitive to radiation.

“A major problem for radiation oncologists at present is that we are bound by the need to avoid damage to normal tissues. This means that the dose of radiation generally used is governed by the response of the most radiosensitive patients and this may lead to many patients receiving lower than optimal doses, hence affecting the ability to deliver a higher dose that may result in better local tumor control,” de Ruysscher said in the press release.

The researchers seek funding from the European Union to launch another project that will help define genetic pathways and build predictive models “that can be implemented in standard clinical practice,” said de Ruysscher. “We believe that if we can understand what is going on at a molecular level, we may be able to develop a blood test that will allow us to know precisely how an individual patient will react to radiotherapy and to target the dose accordingly.”

A press release on this talk can be accessed at http://www.ecco-org.eu.