[Problems of cancer immunotherapy (author's transl)].

Active immunization has received a new impulse most recently through the treatment of tumor cells with the enzyme neuraminidase from Vibrio cholerae. There is no passive specific immunotherapy in humans. In the field of unspecific active immunotherapy there are very many, partly contradictory, findings, especially with BCG, Corynebacterium parvum and preparations from these and other organisms. A cellularly transmitted immunity has been attempted, but so far without very encouraging results. It must be emphasized that all these statements refer to humans.