gms | German Medical Science

Introduction: Thymidylatsynthase is an enzyme for DNA-synthesis and the target for 5-fluorouracil whereas cyclin-D1 plays a critical role in the progression of cells through the G1 phase of the cell-cycle. There is evidence that expression of these markers may predict the outcome of patients with colorectal cancers. The aim of this study was to examine the prognostic value of thymidylatsynthase and cyclin-D1 protein expression in patients with node negative colorectal cancers.

Materials and methods: Thymidylatsynthase and cyclin-D1 protein expression from 140 patients with UICC stage I and II colorectal cancer was analyzed by immunhistochemistry in paraffin-embedded primary tumour specimens.

Results: The 1-, 5- and 10-year overall-survival rates were 96%, 86% and 71% respectively. Tumour stage and recurrence were associated with overall-survival. Low- and high thymidylatsynthase immunoreactivity was present in 68 (48%) and 72 (52%) of cancers, respectively. Low- and high cyclin-D1 immunoreactivity was present in 98 (70%) and 42 (30%) of the cancers, respectively. Patients with high- (n = 72) thymidylatsynthase expressing tumours had a worse overall-survival than patients with low- (n = 68) thymidylatsynthase expressing colorectal cancers (p = 0.011). No difference in overall-survival was seen between patients with high- and low- cyclin-D1 expressing cancers.

Conclusion: Thymidylatsynthase may be helpful as a prognostic marker in lymph node negative colorectal cancer.