The Influences of Genomic Polymorphisms on Treatment Outcomes and Toxicity in Patients with Colorectal Carcinoma

For the last four decades, 5-fluorouracil (5-FU) has been the treatment of choice for colorectal cancer (CRC) in both the advanced and adjuvant settings. In the advanced setting, 5-FU monotherapy produces response rates of only 10% to 20%. Furthermore, in resected stage III CRC, 5-FU monotherapy has increased overall survival by only 20%. The combination of 5-FU with newer therapies such as oxaliplatin and irinotecan, and targeted drugs has significantly improved response rates to approximately 50%. Despite these improvements, approximately half of advanced CRC patients derive no benefit from treatment; this is due to either acquired or inherent drug resistance. This review aims to highlight the current prognostic and predictive markers, especially genomic polymorphisms, which have been identified for CRC to date. The use of these predictive markers might improve the response rates and decrease toxicity for CRC patients, with an ultimate aim to tailor treatment according to individual patient and tumor profile.