Prognostic role of telomerase activity in gastric adenocarcinoma: A meta-analysis.

Activation of telomerase is involved in carcinogenesis in most types of cancers. However, the prognostic value of telomerase activity (TA) in patients with gastric carcinoma (GC) remains controversial. We conducted a meta-analysis to assess the relationship between TA and the clinical outcome of GC. A meta-analysis of 18 studies (886 patients) was performed to evaluate the association between TA and metastasis-related parameters in GC patients by searching databases, including PubMed, MEDLINE, EMBASE, Web of Science databases, Cochrane Library and the Chinese Biomedical Literature database (CBM) (last search updated in October 2011). We used the odds ratios (ORs) with 95% confidence intervals (CIs) to assess the strength of the association between TA and metastasis of GC. Our analysis results indicated that high telomerase activity expression tended to be associated with the presence of lymph node metastasis (866 patients) (OR=2.03, 95% CI 1.21-3.39, p=0.007), the depth of invasion (886 patients) (OR=1.87, 95% CI 1.30-2.70, p=0.0007), distant metastasis (407 patients) (OR=2.71, 95% CI 1.59-4.63, p=0.0002), tumor size (466 patients) (OR=2.14, 95% CI 1.31-3.50, p=0.002) and TNM stage (711 patients) (OR=2.39, 95% CI 1.30-4.41, p=0.005). However, high TA expression was not associated with the presence of histologic differentiation (791 patients) (OR=1.51, 95% CI 0.73-3.11, p=0.26). In conclusion, telomerase overexpression not only plays a key role in primary initiation, but also promotes invasion and metastatic progression of GC. These findings raise the possibility of using TA to screen for the prognosis of gastric cancer.