X-Ray Cross-Complementing Group 1 and Thymidylate Synthase Polymorphisms Might Predict Response to Chemoradiotherapy in Rectal Cancer Patients

XRCC1 G/G and thymidylate synthase (2R/3G, 3C/3G, and 3G/3G) are independent factors of a major response. Germline thymidylate synthase and XRCC1 polymorphisms might be useful as predictive markers of rectal tumor response to neoadjuvant chemoradiotherapy with 5-fluorouracil.