The following review discusses major directions in the research and preparation of various classes of advanced antitumor agents: synthetic materials which work by an alkylating mechanism (derivatives of di (2-chloroethyl)amine, ethylenimine, alkylnitrosourea, dimethyltriazines); platinum derivatives; dispiropiperazines; alkylating agents derived from polyols; various antimetabolites; as well as compounds derived from natural products, such as anthracycline antibiotics, bleomycin, actinomycin, mitomycin, derivatives of aureolic acid, etc. Also discussed are the use of enzymes to destroy substances needed for tumor growth; new plant alkaloids which inhibit mitosis (Vinca alkaloids, Podophyllin toxins, colchamine, etc.); and immunomodulating agents. © 1985 Plenum Publishing Corporation.