Telomerase activity in different clinical staging of colorectal adenocarcinoma

Increased telomerase activity is proposed to be related with the proliferation of some gastrointestinal cancers, including colorectal adenocarcinoma. To date, little is known about the activity of telomerase in different clinical stagings of colorectal adenocarcinoma, which may reflect its association with the progression of colorectal adenocarcinoma. We will examine the activity of telomerase enzyme in different clinical stagings of colorectal adenocarcinoma to know whether it has diagnostic and prognostic value as a tumor marker in the management of colorectal adenocarcinoma. The telomerase activities of primary tumor and normal adjacent mucosa in 17 cases with different clinical stagings of colorectal adenocarcinoma were measured by TRAP assay during the period of 28 September 1998 to 28 February 1999. The activities of the enzyme were measured both qualitatively and quantitatively, and the diagnostic value was assessed by diagnostic test using 2 x 2 table contingency. The association between telomerase activities and other related factors were assessed by multivariate analysis. Increased telomerase activities were found in 82.4% (14/17) of colorectal adenocarcinoma, but in only 23.5% (4/17) of normal adjacent mucosa, which was significantly higher (p = 0.008) compared to that of normal mucosa. The mean values of telomerase activity between different clinical stagings were 0, 0.661, and 1.449 units/410 (g protein for Dukes' stage B, C, and D, respectively, which gave p value of 0.025 with ANOVA. Using a cut off level of 0.2-units/410 (g protein for positive activity, we revealed that the accuracy, sensitivity, and specificity were 77.77%, 82.35%, and 76.47%, respectively. There was no association found between the histopathologic grading of the tumor and telomerase activity. Increased telomerase activity was found in colorectal adenocarcinoma compared to the adjacent normal mucosa. Telomerase activity correlates well with the progression of colorectal adenocarcinoma. Therefore, telomerase enzyme may have a potential diagnostic and prognostic values in the management of colorectal adenocarcinoma.