Pre-requisites to the prescription of chemotherapy in colorectal cancer

Abstract

General and specific considerations have to be taken into account before starting chemotherapy for colorectal cancer to ensure maximal safety. Prescription is restricted by law to physicians specialised or competent in oncology in 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 practionners should be informed about side effects and some specific issues such as sexuality, fertility, contraception, vaccines and driving. This information should be kept simple and reassuring, and should focus on symptoms indicating a serious toxic side effect. Standardized and computerized 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 preventive measures. Specific preventive measures can alleviate the cutaneous side effects of anti-EGFRs and the neurological side effects of oxaliplatin. Life expectancy, comorbidities and standardized oncogeriatric evaluation should be taken into account for older patients. Prescription should be individualized and adapted to liver biology (irinotecan), kidney function (capecitabin and raltitrexed) and cardiovascular status (bevacizumab, 5-FU, capecitabin). Determination of specific molecular caracteristics is needed for prescription of certain drugs (tumor KRAS status before anti-EGFR and tumor microsatellite instability before 5-FU in stade II cancers), while others are still being evaluated (genotyping of UGT1A before irinotecan and DPD before fluoropyrimidines).