Gene Expression Profiling Assays As Predictors of Poor Prognosis in Stage Ii Colorectal Cancer: A Meta-Analysis

15054 Background: The use of adjuvant therapy in stage II colorectal cancer (CRC) remains controversial. There is clearly a need to identify better predictors than the traditional staging system to aid therapeutic decisions. Gene expression profiling (GEP) has been demonstrated as a useful tool in risk stratification in many cancers. We performed a meta-analysis to assess its utility for predicting poor outcomes in stage II CRC. Methods: We performed literature searches of MEDLINE, the Cochrane Library, EMBASE, Cancerlit, and ASCO Proceedings through December 2007. Studies were included if they reported GEP-based assays in patients with stage II CRC, and either subsequent cancer recurrence or death within 3 years. The prognostic likelihood ratio (LR) (sensitivity/ 1-specificity) was obtained for each study and then pooled using the random-effects method to obtain a weighted mean LR and associated 95% confidence intervals (CI). The average accuracy, sensitivity, and specificity are also reported. Results: Eight cohorts with extractable data were identified and included in the analysis. A total of 271 patients were studied, with average follow-up time ranging from 3.0 to 5.6 years. The average accuracy, sensitivity, and specificity were 81.9%, 76.2%, and 84.5%, respectively, with a prognostic LR of 4.54 [95% CI 3.16 to 6.53]. The p value for overall effect was < 0.00001. No evidence for significant inter-study heterogeneity was noted (p = 0.94). Conclusions: This analysis demonstrates promising potential of using GEP assays as predictors of poor outcomes in stage II colorectal cancer, such as cancer recurrence or death. To maximize their utility and availability, further studies will be needed to identify and validate specific gene signatures for poor prognosis in stage II CRC. Author Disclosure Employment or Leadership Consultant or Advisory Role Stock Ownership Honoraria Research Expert Testimony Other Remuneration Almac Diagnostics, H. Lee Moffitt Cancer Center & Research Institute Almac Diagnostics Almac Diagnostics