Biological response modifiers for the therapy of cancer.

I believe that the prospects for therapy of cancer by biological response modification are quite good, particularly since this offers an approach to affecting tumor cells which is substantially different from conventional chemotherapy or radiotherapy. But in view of the quite limited success from empirical approaches with immunotherapy or other forms of biological response modification, and the quite unimpressive results that have been seen in patients with advanced disease, I feel that a shift in emphasis to more systematic and well planned studies is needed. It will probably be necessary to develop a detailed understanding of the mechanisms of action of the various BRMs to better understand the immunoregulatory processes affected by these agents, and to develop protocols which are able to produce optimal and sustained alterations in immunologic reactivity. Since a variety of BRMs have shown considerable antitumor effects in animal tumor model systems, particularly against micrometastatic disease which represents a major clinical problem, further research in this area may be expected to lead to significant advances in the therapy of patients with cancer.