Chemotherapy is the prevention or treatment of disease by the use of chemical substances. The term is sometimes restricted to the treatment of infectious diseases with antibiotics and other drugs or to the control of cancer with antimetabolites (that prevent cell growth) and similar drugs.
During the Second World War, research into the various aspects of the action of mustard gas which is ordinarily poisonous showed that this along with sulphur could destroy dividing cells in lymph nodes and the bone marrow. This harmful effect was harnessed to man’s use for treating some lymphomas with nitrogen mustard. Thus was discovered the first cytotoxic drug against cancer, which damages or destroys cancer cells by inhibiting cell division.
Thereafter many naturally occurring substances were tested for anti-cancer activity on experimental animals resulting in the present availability of some 30 effective anticancer drugs.
Anti-cancer drugs are the treatment of choice for many widely disseminated cancers and serve as adjuncts to surgery and radiation in the treatment of localised ones.
The success of the various combinations of chemotherapy agents used in the treatment of some cancers, has brought hope to the patients.
Unfortunately, these drugs also affect normal cells particularly in bone marrow, skin, stomach lining, and foetal tissue and damage or destroy them, to some extent, resulting in many side-effects which are fairly serious. That is why the search for ideal anti-cancer drugs continues.