Cancer method will buy time

A radical technique for treating bladder cancer, pioneered by scientists at Ulster University, is beginning clinical tests in two hospitals, writes Olga Wojtas.

Surgeons at Altnagelvin Hospital in Londonderry and at Leicester General Hospital are helping to test the technique, known as the comet assay. It appears to be a reliable means of predicting whether tumours will respond well to radiotherapy.

The technique has been developed by Valerie McKelvey-Martin of the university's cancer and ageing research group and Stephanie McKeown of the radiation science research group.

The two main techniques for treating bladder cancer, where the tumour has grown into the bladder wall, are radiotherapy or surgery. But Dr McKelvey-Martin said that about half the patients undergoing radiotherapy failed to respond, and by the time this was established, the tumour had spread.

"If we can demonstrate that the comet assay is able to distinguish between radiosensitive and radio-

resistant tumours, we could select for immediate radiotherapy those patients whose tumour can be destroyed by radiation," she said.

"Those who will not respond to radiotherapy will be identified much earlier and sent for immediate surgery, when the risk of the disease having spread is much less."

Biopsies will help researchers to measure whether the technique's prediction of a tumour's sensitivity to radiotherapy matches what actually happens after three to six months of treatment.

Dr McKelvey-

Martin said the technique could have other applications. "If the comet assay is successful, it may also be possible to give younger, fitter patients with tumours predicted to be moderately radio-resistant, combined chemotherapy and radiation treatment. This combination has been shown recently to improve prognosis in cancer of the cervix."