Purpose: The purpose of the study is to analyze the relationship between tumor thymidylate synthase (TS) mRNA expression levels and raltitrexed/pemetrexed/5-FU sensitivity.
Patients and methods: We collected freshly removed colorectal tumor specimens from 50 patients. Chemosensitivities to anticancer drugs were evaluated by histoculture drug response assay. We adopted quantitative reverse transcription polymerase chain reaction for TS mRNA detection and immunohistochemical staining for assessing TS expression in tumor tissues.
Results: There is a significant relationship between TS mRNA expression levels and in vitro chemosensitivity of freshly removed colorectal tumor specimens to pemetrexed (P < 0.001)/raltitrexed (P = 0.004)/5-FU (P = 0.007).
Conclusions: TS mRNA expression levels can predict pemetrexed and raltitrexed sensitivity in colorectal cancer.