The Predictive Value of Guangzhou Panel for Recurrence in Early-stage Colorectal Cancer

The current risk stratification system defined by clinicopathological features does not identify the risk of disease recurrence in patients with early-stage colorectal cancer (CRC) with optimal accuracy. The investigators aimed to investigate whether the epigenetic alterations could serve as novel prognostic biomarkers that would improve the accuracy of the current primary tumor, regional nodes, metastasis (TNM) staging system. In the current study, the Investigators have analyzed the genome-wide methylation status of cytosine-phosphate-guanosine (CpG) sites using Infinium MethylationEPIC array in primary tumor and adjacent normal samples from 23 recurrent and 22 recurrence-free stage I and II CRC patients to identify potential methylation markers for disease-free survival (DFS). The prognostic value of the candidate biomarkers has been evaluated in a training cohort (n=174) and an independent validation cohort (n=267), and is to be validated in a prospective cohort (estimated n=287). Comprehensive data analysis identified a subset of methylated CpG loci that associated with a high risk of recurrence. Methylated CpGs in four genes were significantly associated with DFS in multivariate analysis in both training and validation cohort. Moreover, Hypermethylated Genes Counts panel using these four markers showed a higher prognostic value than any clinicopathological factor, current molecular biomarkers or single methylated CpG marker alone in the training and validation cohorts. This four-gene methylation assay is defined as Guangzhou Panel. The investigators aim to conduct a prospective observational study to evaluate the predictive value of Guangzhou Panel in early-stage colorectal cancer. A total of 287 patients with pathologically verified stage I-II CRC and underwent surgical resection are expected to be recruited in our study. These patients will be divided into high-risk group and low-risk group and will be followed up at least 5 years. The primary endpoint is 5-year disease free survival (DFS). The prognostic strength of candidate biomarkers was adjusted in multivariate Cox regression models including multiple biomarkers and clinicopathologic variables.