Effect of cancer therapy on host response and immunobiology

The advances in bioengineering and hybridoma technology and the acquisition of basic knowledge about human antitumor defenses have facilitated the development of biologic therapies as a fourth cancer treatment approach. It is becoming important, therefore, to reconsider how conventional therapies affect host responses. It is apparent from the work of many laboratories that both the biologic agents and certain anticancer agents can cause augmentation of antitumor host defenses. These augmenting effects are generally seen at less than maximally tolerated doses. In contrast, at maximally tolerated doses these agents may induce long-lasting untoward effects, some of which (eg, long-term immunodepression) seem incongruent with effective host response-based therapies. This review examines developments in these areas over the past year and suggests that the maximal benefit may not be derived from the combination of chemotherapeutic agents with biologic therapies unless the optimal conditions for their administration in such combinations are redefined.