New test can identify patients who may suffer serious late toxicity from ra...( Copenhagen Denmark: Radiotherapists i...),Health

Dr Mahmut Ozsahin told delegates at ECCO12 The European Cancer Conference today (Monday 22 September) that the test was very precise. "It is capable of isolating 93% of those patients, with nearly 99% exactitude, who will suffer no increased late toxicity when using traditional doses," he said. "This means that radiotherapists can give those patients a more aggressive treatment that will be more likely to kill more cancer cells with only a slight increase in toxic side effects. This is a very significant result because it has been estimated that if you exclude 5% of the most sensitive patients, you can gain a 20% increase in the local control of many tumours in the remaining 95% of patients with only a slight increase in radiation dose."

Dr Ozsahin, a consultant radiation oncologist and associate professor at Centre Hospitalier Universitaire Vaudois in Lausanne, Switzerland, and his colleagues, took blood samples from 399 cancer patients between 1998 and 2000 and irradiated the samples. They looked at two T-lymphocytes (white blood cells) CD4 and CD8 to see what effect radiation had on cell death (apoptosis). The process took only 48 hours. Then they correlated the results with the responses of the patients to radiotherapy.

They found that there was no correlation between the early onset of toxic side effects and T-lymphocyte apoptosis. However there was a statistically significant correlation with grade two and three late toxicity. Patients who suffered grade two and three late onset side-effects had blood samples in which radiation-induced apoptosis was below the median average. "Patients whose CD4 and CD8 T-lymphocytes suffered the least cell death were the most sensitive to late toxicity," said Dr Ozsahin.

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Contact: Margaret Willson
m.willson@mwcommunications.org.uk
45-3252-4163
Federation of European Cancer Societies
22-Sep-2003