This meeting has enabled those actively involved in the clinical investigation of IFN alfa-2a to present the most recent data available on 5 different types of tumour. There is now no doubt that recombinant IFN has an effect on the growth of several malignant disorders. In Kaposi's sarcoma and hairy cell leukaemia its role is, perhaps, clearest. In the other diseases which have been discussed, intriguing response data have been obtained but, as yet, there are no defined categories of patients in whom IFN alfa-2a can be identified as the treatment of choice. Only further painstaking clinical research can provide the answers to the many questions raised by current studies of this fascinating compound. How can we reduce its unwanted effects? At what point in the natural history of a tumour should it be used to exert its maximum effect? How should it be combined with other anticancer therapy? Recent advances in molecular biology are beginning to address the key question of how it works. By dissecting the molecular machinery of the cell, more will surely be learned of the mechanism of action of IFN as well as the nature of cancer itself.
I should like to thank all the presenters for such excellent reports, Hoffmann-La Roche for sponsoring this satellite symposium and the audience for its interest and participation.