Prognostic significance of thymidylate synthase expression in the adjuvant chemotherapy after resection for pulmonary metastases from colorectal cancer.

BACKGROUND Recent studies have discussed on the prognostic value of thymidylate synthase (TS) assessment in metastases of colorectal cancer (CRC). The aim of this study was to evaluate the prognostic significance of molecular biomarkers including TS expression, after pulmonary metastasectomy followed by 5-fluorouracil-based adjuvant chemotherapy. PATIENTS AND METHODS A total of 80 patients who underwent metastasectomy for pulmonary recurrence from CRC were included in this study. Tumor sections were stained by immunohistochemistry for TS, orotate phosphoribosyltransferase (OPRT), dihydropyrimidine dehydrogenase (DPD), excision repair cross-complementation group 1 (ERCC1), breast cancer susceptibility gene 1 (BRCA1), vascular endothelial growth factor (VEGF), microvessel density (MVD) assessed by CD34 and p53. RESULTS Survival after pulmonary metastasectomy was significantly longer in patients treated by adjuvant chemotherapy than those without adjuvant therapy. TS, OPRT, ERCC1, BRCA1 and CD34 expression was significantly associated with better outcome from the use of adjuvant chemotherapy. CONCLUSION Expression level of TS, OPRT, ERCC1, BRCA1 and MVD in resected colorectal lung metastases may play an important role for predicting outcome after 5-fluorouracil-based adjuvant therapy.