Impact Of Anti-Vegf Therapy In Metastatic Colorectal Cancer With An Intact Primary Tumour.

650 Background: The management of metastatic colorectal cancer (mCRC) with anti-VEGF therapy and a fluoropyrimidine-containing chemotherapy is well established in first and second line therapy. However the role, safety and benefits of anti-VEGF therapy (Bevacizumab) in specific subgroups including those with an intact primary tumour (IPT), are not well described. Methods: Consecutive mCRC pts enrolled from January 2009 were identified from a prospective multi-site Australian registry. Survival and key safety endpoints were explored for pts with an IPT versus pts with a resected primary (RPT). Differences in outcomes were compared using log-rank test and Kaplan-Meier curves. Results: Of 1,204 pts with mCRC, 826 (69%) eligible pts were identified. Anti-VEGF therapy use in the first-line setting was similar in pts with an IPT [200/313 (64%)] vs. a RPT [357/513 (70%)]. In both groups the addition of anti-VEGF therapy was associated with greater PFS; IPT 8.5 vs. 4.7 months (HR 0.73, p=0.017) and RPT 10.8 vs. 5...