ABSTRACT
Whilst radiotherapy has been used as a treatment for cancer for just over a century, chemotherapy only began to emerge following the end of the Second World War. The first chemotherapy drugs were identified in the 1940s and 1950s by tests on animal tumours. These tumours were, typically, rapidly dividing mouse tumours such as the L1210 mouse leukaemia and such tumours, not unexpectedly, selected for cytotoxic (cell killing) drugs which were particularly effective against rapidly dividing cells. A range of different cytotoxic drugs was discovered and unlike radiotherapy, which only kills cells by directly damaging DNA, cytotoxic drugs were found to be able to prevent cells dividing in a variety of ways. However, only a small percentage of drugs which were discovered to kill dividing cells in experimental systems have finally proved to be useful in the treatment of cancer in the clinic.
