Prognostic value of thymidylate synthase expression in colorectal cancer

A i m. The aim of the study was to define the prognostic value of thymidylate synthase (TS) expression in colorectal cancer (CRC), and its role as a predictor of the chemotherapeutic benefit in patients treated with fluorouracil (5-FU). Material and methods . TS expression was immunohistochemically assessed on primary tumor archival specimens from 120 patients with CRC. Results . For the entire study population the univariate analysis revealed that TNM stage, surgical margin, vessel invasion, and TS expression were significant prognostic factors. In a subgroup treated with 5-FU (n=98) overall survival correlated with tumor location, TNM stage, surgical margin, and TS expression. Multivariate analysis demonstrated that tumor stage, TNM stage, and TS expression were independent prognostic factors. In the subgroup treated with 5-FU only tumor location, tumor stage, and TNM stage correlated with survival. Conclusions . TS expression in primary tumors was a significant, independent prognostic factor in colorectal cancer. The evaluation of its predictive role requires further investigations.