Interferon treatment of human malignancies--a short review.

Interferon (IFN) therapy can induce remissions in human malignancies and has been established as a treatment of choice in several diseases. The clinical effects of IFNs are especially obvious in the treatment of hematological malignancies and virus-associated tumor diseases. Most other types of malignant solid tumors are less likely to respond to IFN as monotherapy and optimal therapeutic schedules are yet to be developed. It is of special interest that combinations of IFNs with other treatment modalities have yielded an increased response rate in several diseases. Several studies on the use of IFN as adjuvant therapy are under way. It is possible, if not likely, that the antitumor effects of IFNs are mediated by different cellular effects in cooperation. These may differ between different malignancies. Mainly based on studies comparing in vitro sensitivity of malignant cells to clinical effects on the same tumor, we suggest that the direct effects of IFNs on the malignant cell are of major importance for the antitumor action of IFN. A deepened insight into the cellular aspects of the antitumor action of these cytokines is a prerequisite for the optimal use of IFNs in the treatment of tumors in man.