High Telomerase Activity Is an Independent Prognostic Indicator of Poor Outcome in Colorectal Cancer

Telomerase activity and altered telomere length have been extensively studied in many kinds of malignant tumors for clinical diagnostic and/or prognostic utilities. In the present study, we investigated telomerase activity and telomere length in colorectal cancers and noncancerous colonic mucosa specimens in 100 patients between 1991 and 1996. To determine whether the level of telomerase activity or telomere length is a prognostic indicator of patient outcome, we followed these patients more than 3 years after surgery. Among 100 primary colorectal cancer specimens, 96 specimens had telomerase activity. Because noncancerous mucosa has some detectable telomerase activity, we divided the levels of telomerase activity into three categories: high (>50-fold more than that in noncancerous mucosa); moderate (10- to 50-fold); and low (