ROLE OF IMMUNOTHERAPY IN MALIGNANT-MELANOMA OF THE HEAD AND NECK

There is an urgent need for more effective treatments for patients wit h metastatic melanoma and patients at high risk of relapse following r emoval of the primary tumour. Cytokines, used alone or in combination or adoptive cellular therapy, give responses in around 20-25% of patie nts with metastatic disease. The same results are seen with very simpl e, single-agent chemotherapy regimens, which are markedly cheaper. Reg ressions achieved by immunotherapy, however, tend to last longer, sugg esting a basic alteration in the balance between host and tumour. Rati onal immunotherapy has been made possible by the discovery of antigens expressed on melanoma cells which are capable of being recognised by autologous, cytotoxic T lymphocytes. The availability of synthetic pep tides as immunogens, together with a range of new adjuvants, offers sc ope for the development of effective, vaccination schemes. It is now p ossible to transfect cells with genes for cytokine production, a techn ology which opens up new ways to stimulate the immune system. Tumour c ells have a variety of defects which make them poor stimulators of the immune system. By using as an immunogen, autologous tumour cells tran sfected with genes such as those for interleukin-2 or granulocyte-macr ophage-stimulating factor (GM-CSF), and then irradiating the cells to prevent further tumour growth, one is able to induce tumour recognitio n much more effectively. This may lead to destruction of tumour at oth er sites, or may prevent the outgrowth of residual tumour cells when t hese immunogens are used as adjuvants. The potential offered by these new technologies is enormous. Only cooperative clinical studies, which will involve the referral of patients to specialist centres, will. en able us to explore these promising new developments.