ABSTRACT
Although new anticancer drug families, such as camptothecin and platinum derivatives, are of great interest in the treatment of colorectal cancer, their therapeutic index (i.e. the ratio of the theoretical minimum effective dose to the maximum tolerated dose) remains narrow compared with that of older drugs. The antitumour specificity of chemotherapy drugs is far from complete, and toxic side-effects are often observed – even in conventional regimens. Moreover, efficacy remains limited because of the wide panel of resistance mechanisms that can be displayed by colorectal cancer cells. On the other hand, retrospective analyses have strongly suggested a relationship between drug dose and tumour response, and have emphasized the impact of dose intensity on the response rate.1-5 Up to now, doselimiting haematological and non-haematological toxicities have hindered the development of intensive dose strategies.
