ADAGE - Prodige 34

Colorectal cancer occurs mainly in elderly patients. Recent estimation showed that in France more than 50% of the patients diagnosed with a colorectal cancer are 70 years old or more. Adjuvant chemotherapy has demonstrated a benefit on disease-free survival and overall survival after a stage III colon cancer resection. Nevertheless adjuvant chemotherapy is poorly used in elderly patients. Prognostic improvement with chemotherapy based on 5FU is suggested by a post-hoc analysis of randomized prospective clinical trial. But elderly patients in this study were highly selected and patients older than 80 represented only 0.7% of the total population. Thus, there is still a concern about the benefit of adjuvant 5FU-based chemotherapy in very elderly unselected patients.;The recommended treatment for stage III adjuvant chemotherapy is a combination of fuoropyrimidine and oxaliplatin. Nevertheless oxaliplatin did not demonstrated survival advantage in elderly patients.;Altogether there are still two matters of debate:;ÀFirst, is there a benefit of fluoropyrimidine-based adjuvant chemotherapy for unfit elderly patients?;ÀSecond, is there a benefit of oxaliplatin-based adjuvant chemotherapy for fit elderly patients? The aim of this randomized phase III study is to evaluate the benefit for disease-free survival of adjuvant chemotherapy in elderly patient and which chemotherapy.;The elderly patient population will be dichotomized into two groups according to physician's choice after a multidisciplinary evaluation involving a geriatrician, with two different randomization assignments. The patients with an expected life-expectancy below 4 years according Lee score are excluded of this study.;Some biological tumour abnormalities are more frequently observed in elderly (i.e. mismatch repair deficiency), therefore an evaluation of specific biological prognostic factors is needed in elderly population.