ABSTRACT
Anticancer drugs have been developed and used medically since the 1940s, following the observation that nitrogen mustard gas, a chemical warfare agent used in the Second World War, interfered with haematopoiesis. There are several proposed mechanisms of action of monoclonal antibodies as anticancer agents. Chemotherapy aims to exploit the resulting differences in biological and proliferative characteristics between normal and cancer cells where most cytotoxic drugs preferentially affect dividing cells in tumours. Most antitumour antibiotics have been produced from bacterial and fungal cultures. Some drugs like alkylating agents and platinum derivatives have an equal effect on tumour and normal cells whether they are in the proliferating or resting phase. Cells respond to their environment via external signals called growth factors. There are two main types of cell death: apoptosis and necrosis. Cytotoxic chemotherapy agents have traditionally been classified as phase-specific or non-phase-specific, depending on the effect on the cell cycle.
