Prérequis avant l'administration et prévention des effets secondaires d'une chimiothérapie pour cancer colorectal

Some general and specific, statutory, clinical and biological parameters have to be taken into account before beginning chemotherapy in colorectal cancer to ensure maximal safety. Statutorily the prescription is reserved to specialised or competent physicians in oncology in some accredited institutions. It is essential to conform to indications, contraindications and posology, and to have a good knowledge of safety measures, drug interactions and side effects. Patients, family members and general practitioners should be informed about side effects, without forgetting some thematics (sexuality, fertility, contraception, vaccines, driving). This information should be simple, adapted and “reassuring”, but should focus on symptoms indicating a serious toxic side effect. The message can be optimized by nurse consultation, transmission of the individualized care plan and linkage notebook, such as oral chemotherapies (capecitabine, UFT). The computerized and standardized prescription is done after infusion line inspection, clinical examination (global health status, nutritional status and buccodental status) and review of relevant pathological, radiological and biological data. Management of side effects includes patient education, appropriate premedication and prescription of prophylactic supportive care. Some specific preventive measures can attenuate the cutaneous side effects of EGFR inhibitors and the oxaliplatine-induced sensory neurotoxicity. Life expectancy, comorbidities, level of dependence, and if possible the comprehensive geriatric assessment should be taken into account for elderly patients. Prescription should be individualized and adapted to liver biology (irinotecan), kidney function (capecitabine and raltitrexed) and cardiovascular status (bevacizumab, 5-FU, capecitabin). Some molecular biologic prerequisites are indicated: detection of tumor KRAS-BRAF mutation before anti-EGFR and tumor microsatelliteinstability status before 5-FU in stage II cancers. Clinical relevance of others pretherapeutic molecularparameters are still being evaluated: UGT1A1 genotyping before irinotecan and detection of dihydropyrimidine dehydrogenase deficiency before fluoropyrimidines.