Phase II Study of Bevacizumab and Chemoradiation in the Preoperative or Adjuvant Treatment of Patients With Stage II/III Rectal Cancer

Sixty-six patients with rectal cancer received bevacizumab in addition to chemotherapy and radiation. This trial sought to determine if adding bevacizumab would produce a benefit for patients before or after surgery. Some patients' cancer improved but there were side effects, some severe. Patients should be cautioned about risks associated with adding bevacizumab to this type of therapy, particularly after surgery. Background and Purpose: We wanted to evaluate the efficacy, defined as 2-year disease-free survival (DFS), and safety of bevacizumab/chemoradiation in preoperative and adjuvant settings for patients with stage II/III rectal cancer. Patients and Methods: Eligible patients had stage II/III rectal adenocarcinoma, Eastern Cooperative Oncology Group performance status (ECOG PS) 0-1, and adequate organ function, and received preoperative (cohort A) or adjuvant (cohort B) treatment at physician discretion. Patients received 5-fluorouracil (5-FU) as an intravenous infusion (IVCI) 225 mg/m(2)/d on days 1-42, bevacizumab 5 mg/kg intravenously (IV.) on days 1 and 15 (cohort A), or every 2 weeks (cohort B), with radiation therapy to 50.4 Gy. After surgery (cohort A) or chemoradiation (cohort B), FOLFOX6 (5-fluorouracil, leucovorin, oxaliplatin) and bevacizumab were administered for 4 months and then bevacizumab was given alone for up to 1 year. Results: Sixty-six patients (cohort A = 35; cohort B = 31) were enrolled from August 2006-April 2009: median age was 57 years; male patients, 62%; ECOG PS 0, 75%; stage 31%/69%. In cohort A, the complete pathologic response (pCR) rate was 29% (11% microscopic residual disease, 49% gross disease). Four patients did not undergo surgery (toxicity, 2 patients; progressive disease, 1 patient; patient decision, 1 patient). One- and 2-year DFS for cohorts A/B were 85%/not reached and 97%/89%, respectively (median survival not reached for either cohort). Frequent grade 3/4 toxicity included diarrhea (A cohort, 14%; B cohort, 29%), neutropenia (A cohort, 14%, B cohort, 23%), mucositis (A cohort, 23%, B cohort, 0%), and fatigue (A cohort, 6%, B cohort, 10%). Other serious toxicity included bowel perforation and pelvic infection (cohort A, 1 patient each), bowel perforation (2 patients), anal wound dehiscence (1 patient), perianal infection (2 patients), and rectovaginal fistula (1 patient) (cohort B), without treatment-related death in either cohort. Conclusions: Bevacizumab can be added to standard preoperative and adjuvant chemoradiation in most patients with expected and manageable toxicity and may increase treatment efficacy.