Abstract LB-76: A study of neoadjuvant bevacizumab with standard chemoradiation versus chemoradiation alone in locally advanced rectal cancer

Abstract

Abstract The anti-vascular endothelial growth factor (VEGF) antibody bevacizumab is increasingly being tested with pre-operative (neoadjuvant) regimens in patients with localized cancer, but its effects on metastasis and survival remain unknown. This study examined the outcome of clinical stage II/III rectal cancer patients treated on a prospective phase II study of bevacizumab based chemoradiation and surgery to a contemporarily treated group of patients with standard chemoradiation and surgery at the same institution (Duke University Medical Center). Outcome analyses were performed on: 1. thirty-two patients treated prospectively from 2002 to 2008 with neoadjuvant bevacizumab, 5-fluorouracil and radiation therapy and surgery; versus 2. forty-two patients treated from 2004 to 2008 with capecitabine, radiation therapy and surgery. The current median follow-up is 3 years. While local control was 100% in both groups (i.e., there was no local recurrence), the patients treated with bevacizumab-based chemoradiation and surgery showed statistically significantly higher overall survival rates and a trend higher disease-free survival rates than patients treated with chemoradiation alone and surgery. No statistically significant differences were observed in local control or toxicity between the two groups. These data indicate that adding bevacizumab to neoadjuvant chemoradiation compares favorably to chemoradiation alone in a contemporary population of rectal cancer patients. The efficacy of neoadjuvant bevacizumab will have to be established prospectively in randomized studies, but bevacizumab with standard chemoradiation and surgery shows promising safety profiles and does not appear to increase metastasis after three years in locally advanced rectal cancer patients. This study was partially supported by NIH grants R21-CA99237, P01-CA80124, R01-CA115767, R01-CA85140, R01-CA126642 and Federal Share/NCI Proton Beam Program Income grants, and by the National Foundation for Cancer Research. Citation Format: {Authors}. {Abstract title} [abstract]. In: Proceedings of the 101st Annual Meeting of the American Association for Cancer Research; 2010 Apr 17-21; Washington, DC. Philadelphia (PA): AACR; Cancer Res 2010;70(8 Suppl):Abstract nr LB-76.