The scientific bases of cancer management: at the interface between fundamental research and clinical practice.

From 1950 to 1985 the 5-year survival rate of cancer patients in industrialized countries, has slowly increased from 25% in 1950 to 50% in 1985. This progress has been due to earlier diagnosis and to a gradual improvement of treatment modalities. Clinical needs have stimulated basic research and clinical investigation. In turn, biological research has introduced new concepts and new agents. Clinical investigation and applied research have brought about an improvement in therapeutic methods and a better understanding of the growth and progression of human cancers which has, in particular, led to the concept of adjuvant treatment of occult metastases. The major recent breakthroughs in fundamental research have reinforced the value of close cooperation between clinicians and fundamentalists. Most of the new biologic tools are specific and only active on tumors cells with well-defined characteristics. Furthermore some new techniques such as adoptive immunotherapy can induce complete tumor regression in some patients and have no detectable effects in other patients with apparently similar tumors. Some cytokines have different effects on experimental and human tumors. The cytokine network is so complex that the administration of one of them can induce unpredictable effects. It has been recognized that experimental tumors and in vitro studies can be misleading and there is no substitute for clinical studies on patients. Moreover clinical experience has documented the amazing ability of tumors to become resistant to all these new agents. Numerous new therapeutic methods are being explored, however with the current state of knowledge it appears that although they can help to control tumors, they still fail to eradicate them. We must therefore learn how to integrate them with conventional therapies. Advances in therapy shall be achieved only by well-designed clinical trials. Thus at the interface between fundamental research and clinical practice there is an urgent need for oncologists with a strong scientific background and laboratory scientists with a deep interest in clinical investigations.