Cancer Research Campaign review of radiobiology research.

The meeting was reviewed and summarised by Professor Herman Suit. He judged that the potential clinical gains from research in radiobiology were very great and likely to translate to improved cancer treatment in the near future. He was highly complimentary about the contribution of UK research in radiobiology and he indicated that this viewpoint was held widely in the United States, Europe and Japan. Radiobiological research was the basis for major clinical trials in radiotherapy undertaken by trial groups in all these countries. He felt that major contributions to current practice in radiotherapy had been the definition of dose response, the rationale for the use of radiotherapy against slowly responding tumours, and the understanding of repair differentials and of clonal proliferation in the design of clinical fractionation trials, leading to clear demonstration of benefit for altered fractionation in the treatment of head and neck cancer and in the treatment of bladder cancer. An important goal of research should be the development of predictive testing for radiation response employing multiple predictive tests of radiation sensitivity (survival at 2 Gy), cellular proliferation (potential doubling time) and identification of hypoxic cells, together with physiological parameters such as blood flow intratumoral pressure, thiol metabolism and activation and status of repair genes. In terms of improving differential response between tumour and normal tissues, further refinement of dose fractionation patterns would be needed, but also research should continue on the modification of response using drug/radiation protocols, targeting techniques, growth factors and other biological response modifiers to support normal tissues, and modulation of DNA repair. Professor Suit felt that the pace of research in radiobiology was most encouraging for the field of radiotherapy. There was a consensus that support for radiobiology needed to be matched by support for academic radiotherapy if potential research gains were to be translated into advances in treatment. He shared the view expressed by the Committee of Cancer Experts of the EORTC that improvements in cancer cure over the next decade were likely to derive from improvements in radiotherapy.