LGR5 rs17109924 to predict chemoresistance to 5FU-based chemotherapy in adjuvant colon cancer.

3580 Background: We recently investigated 25 germline polymorphisms in a comprehensive panel of genes that have been previously associated with colon cancer stem cell genes to predict tumor recurrence in patients with stage III and high-risk stage II colon cancer treated with 5-FU based chemotherapy. We found the minor alleles of CD44 rs8193 C>T, ALCAM rs1157 G>A and LGR5 rs17109924 T>C being significantly associated with increased time to recurrence (TTR). In this study we validated these molecular biomarkers in a large and independent study cohort to clarify their predictive and/or prognostic role. Methods: A total of 599 consecutively collected patients with stage II and III colon cancer were included in this validation study. Genomic DNA was analyzed for CD44 rs8193, ALCAM rs1157, and LGR5 rs17109924 by TaqMan 5'-exonuclease assays. Results: The mean age at time of diagnosis was 64 years (std 11), with a median follow-up time of 4.2 years (range 0.1-16.6). Tumor recurrence was observed in 185 (30.9%) ...