Bevacizumab With Pelvic Radiotherapy And Primary Chemotherapy in Patients With Poor-Risk Rectal Cancer

To determine the pathological complete response (pCR-TRG1) rate in patients treated with 2 different schedule of bevacizumab plus primary chemotherapy and radiotherapy of the pelvic region when optimal surgery is applied.

Bevacizumab will be given by intravenous infusion at the dose of 5 mg/kg concurrent with chemotherapy and radiotherapy every 2 weeks for 4 cycles from -14 days to start chemo-radiotherapy (classical schedule) or 4 days before the concurrent administration of chemotherapy and radiation therapy for 2 cycles if the number of TRG1 was not reached in the first stage with the classical schedule Simon's methods will be used to calculate sample size.Setting a and b errors as 0.05 and 0.20, respectively, and defining as minimum activity of interest (p0) a TRG1 rate=30%. In order to demonstrate a TRG1 rate ≥50% (p1), at least 6 TRG1 on the first 15 patients, and at least 19 TRG1 on a total of 46 patients should be reported in the first and second stage, respectively.

Inclusion criteria

• Patients with histologically or cytologically confirmed diagnosis of locally advanced rectal cancer (LARC) at high risk of recurrence (T4, N+, T3N0 with tumor located in the lower third of the rectum and/or circumferential resection margin (CRM) £5 mm), or LARC with resectable organ metastasis (M1).
• Age 18 years or older
• Eastern Cooperative Oncology Group (ECOG) Performance Status 0-2
• Life expectancy of at least 12 weeks
• Measurable and/or evaluable (resectable organ metastasis)lesions according to RECIST criteria
• Neutrophils > 1500 and Platelets > 100,000 /L
• Total bilirubin < or = 1.5 time the upper-normal limits (UNL) of the Institutional normal values and ASAT (SGOT) and/or ALAT (SGPT) < or = 2.5 x UNL, or < or = 5 x UNL in case of liver metastases, alkaline phosphatase < or = 2.5 x UNL, or < or = 5 x UNL in case of liver metastases.
• Creatinine clearance > 50 mL/min or serum creatinine < or = 1.5 x UNL
• Urine dipstick of proteinuria < 2+. Patients discovered to have > or = 2+ proteinuria on dipstick urinalysis at baseline, should undergo a 24-hour urine collection and must demonstrate < or = 1 g of protein/24 hr.
• Written informed consent.
• Patients must be accessible for treatment and follow up. Patients registered on this trial must be treated and followed at the participating Center

Exclusion criteria

• Prior radiotherapy or chemotherapy for rectal cancer.
• Untreated brain metastases or spinal cord compression or primary brain tumours
• History or evidence upon physical examination of CNS disease unless adequately treated (e.g., seizure not controlled with standard medical therapy or history of stroke).
• History of inflammatory bowel disease and/or acute/subacute bowel occlusion
• Serious, non-healing wound, ulcer, or bone fracture
• Evidence of bleeding diathesis or coagulopathy.
• Uncontrolled hypertension
• Clinically significant (i.e. active) cardiovascular disease, for example cerebrovascular accidents (≤ 6 months), myocardial infarction (≤ 6 months), unstable angina, New York Heart Association (NYHA) grade II or greater congestive heart failure, serious cardiac arrhythmia requiring medication
• Current or recent (within 10 days prior to study treatment start) ongoing treatment with anticoagulants for therapeutic purposes.
• Chronic, daily treatment with high-dose aspirin (>325 mg/day) or other medications known to predispose to gastrointestinal ulceration.
• Treatment with any investigational drug within 30 days prior to enrolment.
• Patients with known allergy to Chinese hamster ovary cell proteins, or any of the components of the study medications
• Other co-existing malignancies or malignancies diagnosed within the last 5 years with the exception of basal and squamous cell carcinoma or cervical cancer in situ
• Major surgical procedure, open biopsy, or significant traumatic injury within 28 days prior to study treatment start, or anticipation of the need for major surgical procedure during the course of the study.
• Pregnant or lactating women. Women of childbearing potential with either a positive or no pregnancy test at baseline. Postmenopausal women must have been amenorrheic for at least 12 months to be considered of non-childbearing potential. Sexually active males and females (of childbearing potential) unwilling to practice contraception during the study.