Pathological complete response, (pCR) correlates with a favourable overall prognosis in locally advanced rectal cancer patients underwent preoperative chemoradiation, so obtaining a pCR might be beneficial. The aim of the study is to investigate safety and efficacy of preoperative IMRT combined with bevacizumab and capecitabine. primary endpoint is pathological complete remission rate.

Inclusion Criteria:

• Male or female patients with histologically proven adenocarcinoma of the rectum ,T3/4 or any node positive disease (clinical stage according the TNM classification system)
• No evidence of metastatic disease.
• Age 18 - 65 years
• Kps 80-100
• No prior radiotherapy, chemotherapy or any targeting therapy for rectal cancer
• Normal hematological, hepatic and renal function, Ability to swallow tablets
• Signed informed consent
• Patients must be willing and able to comply with the protocol for duration of the study

Exclusion Criteria:

• Malignancy of the rectum other than adenocarcinoma

  • Other co-existing malignancy or malignancy within the past 5 years, with the exception of adequately treated in situ carcinoma of the cervix or basal cell carcinoma of the skin
  • Significant heart disease (uncontrolled hypertension despite of medication (> 150/100 mmHg), NYHA class III or IV heart disease,unstable angina or myocardial infarction within the past 1 year prior the study entry, history of significant ventricular arrhythmia requiring treatment)
  • Evidence of active peptic ulcer or upper GI bleeding
  • Evidence of bleeding diathesis or coagulopathy
  • Patients receiving a concomitant treatment with drugs interacting with capecitabine such as flucitosine, phenytoin, or warfarin
  • Known hypersensitivity to biological drugs
  • Treatment with any investigational drug within 30 days before beginning treatment with the study drug
  • Pregnant or lactating patient