Genetic variations within the vitamin C transporter genes to predict outcome in metastatic colorectal cancer patients treated with first-line FOLFIRI and bevacizumab: Data from FIRE-3 trial.

11507Background: Vitamin C is involved in many critical metabolic processes. Beside its major role as an antioxidant and free radical scavenger vitamin C exerts a regulatory influence on angiogenesis. Additionally, epidemiologic studies show an association between vitamin C levels and incidence of cancer.We therefore hypothesize that variations in genes encoding for vitamin C transporter proteins may predict outcome in patients (pts) with metastatic colorectal cancer (mCRC) treated with FOLFIRI and bevacizumab (bev). Methods: Theimpact of 3 functional SNPs within the SVCT1, SVCT2 and Glut1 genes on outcome was evaluated in 292 pts with mCRC treated with first-line FOLFIRI/bev in the randomized phase III FIRE-3 trial. 294 pts receiving FOLFIRI and cetuximab (cet) (FIRE-3) served as a negative control. Genomic DNA was extracted from formalin fixed paraffin embedded tissue and SNPs were analyzed by PCR-based direct sequencing. Results: Baseline characteristics in the FOLFIRI/bev arm were as follows: female/m...