Study of Neoadjuvant Chemotherapeutic Treatment (XELOX) Followed by Chemoradiotherapy (XELOX/RT) and Surgery Versus Chemoradiotherapy Followed by Surgery and Chemotherapy in Patients With High Risk Rectal Cancer

Inclusion Criteria: * Patients with rectal adenocarcinoma. * Operable tumour, confirmed by magnetic resonance of high resolution and / or endorectal echography, or, * Rectal tumour at distal third, or * Tumours spread more than 5 mm in perirectal fat * Functional state ECOG ≤ 2. * Good hematological, hepatic and renal function Exclusion Criteria: * Previous pelvis radiotherapy. * Previous antitumoural chemotherapy * Pregnant or breastfeeding women. * Childbearing women with a positive pregnancy test result at baseline. Menopausal women should not have the period for the last 12 months. * History of any other neoplastic illness within the last 5 years, except for already resolved small cell skin cancer or cervix cancer. * Clinically significant cardiovascular disease * Confirmed peripheral neuropathy. * Gastrointestinal disorders or bad absorption syndrome or non-capable to take oral medication. * Blood disorders. * Intercurrent non-controlled or severe infections. * Patients who have undergone major surgery, open biopsies or with significant trauma lesions within the previous 28 days. The above information is not intended to contain all considerations relevant to a patient's potential participation in a clinical trial.