XELOX+Bevacizumab Followed by Capecitabine+Bevacizumab+Radiotherapy as Neoadjuvant Treatment of Locally Advanced Rectal Adenocarcinoma

Inclusion Criteria: * Written informed consent from patients who are able to understand the study request * Histologically confirmed diagnosis of locally advanced rectal adenocarcinoma; ≤12 cm from the anal margin; T3, operable T4 or TxN+ * Karnofsky PS Index ≥ 70% * Life expectancy \> 6 months * Adequate bone marrow, liver and renal function: ANC ≥ 1.5 x 10e9/l; Platelets ≥ 100 x 10e9/l; Hb ≥ 9g/dl; INR ≤ 1.5; Bilirubin ≤ 1.5 x ULN; ALT and/or AST ≤ 2.5 x ULN or ≤ 5 x ULN (in case of hepatic metastasis); Alkaline phosphatase ≤ 2.5 x ULN or ≤ 5 x ULN (in case of hepatic metastasis) or ≤ 10 x ULN (in case of bone metastasis); Creatinine clearance (Cockcroft-Gault) ≥ 30 ml/min or seric creatinine ≤ 1.5 x ULN Exclusion Criteria: * Distant metastases; previous neoplasm during last 5 years or previous infiltrating neoplasm; previous treatment with radiotherapy or study drugs; recruited for other clinical trial in 4 weeks before study entry * Surgery, open biopsy or traumatic injury in 4 weeks before study entry; fine-needle aspiration in 7 days before study entry; major surgery planned during study * Previous heart disease or uncontrolled hypertension, previous hemorrhagic diathesis or coagulopathy; full-dose oral or parenteral anticoagulant or thrombolytic agent (low-dose warfarin is allowed, INR ≤ 1.5); chronic use of high-dose aspirin (\<325mg/day) or non-steroidal anti-inflammatory treatment * No integrity of the upper gastrointestinal tract, malabsorption syndrome or unable to take oral drugs * Pregnant or lactating patients; SNC disease; allogeneic transplant with immunosuppressive drugs; bone fracture not healed, wound or severe ulcers; uncontrolled intercurrent severe infections; previous related-fluoropyrimide SAEs or DPD deficiency