Immunotherapy of brain tumors.

The fight against neoplasia still represents a formidable challenge. At the present time the mechanism of cell-mediated immunity seems to offer the most promise. At the same time, one is cautioned by the implication that minimal cell-mediated responses threaten acceleration of tumor growth. Therefore, one is impressed with the need for investigation of these approaches in a model system prior to their application to humans. The data currently available suggest that when active tumor growth is present within the host, a state of immune deficiency exists: cell-mediated immune responses may be quantitatively deficient or this response may be negated by the presence of blocking factor in the serum. Efficient and effective immune responses imply adequate cell-mediated immunity and the absence of blocking factor activity within the serum.