ABSTRACT
Antineoplastic agents, traditionally referred to as chemotherapeutic agents, are used therapeutically in the treatment of cancer. The drugs include a wide variety of diverse chemicals whose mechanism of action is targeted toward arresting the aberrant cell proliferation generally associated with cancerous cell growth. Antimetabolites alter normal cellular functions by substituting for components within key metabolic processes. An agent may be incorporated as a substrate or may inhibit the normal functioning of an enzyme. Pentostatin is often classified as an antimetabolite, although it is derived from microorganisms. It acts as a transition state analog and interferes with adenosine deaminase. The basis of hormonal anticancer therapy is the interaction of synthetic nonsteroidal chemicals with nuclear and cell membrane growth-stimulatory receptor proteins. The drugs have the advantage of greater specificity for tissues responsive to their counterbalancing effects, such as breast, endometrium, testes, and prostate.
