Identification of an autophagy-related gene expression signature for colorectal cancer

Autophagy, a major lysosomal degradation process, has been implicated in the pathogenesis of colorectal cancer (CRC). However, it still remains unclear what role all the autophagy-related genes (ARGs) play in CRC prognosis. A univariate Cox analysis was conducted to select ARGs related with overall survival (OS) for CRC cohort of the TCGA database. A multivariate Cox analysis was used to develop an ARGs expression signature, whose risk score stratified CRC patients into two groups. The OS time between the above two groups was estimated using the Kaplan-Meier curve and log-rank test. In order to evaluate the predictive performance of this expression signature and other clinicopathological parameters for CRC prognosis, the area under the curve (AUC) was calculated. Nine out of 20 OS-related ARGs were finally incorporated into this ARGs expression signature, whose risk score stratified CRC patients into either high-risk or low-risk group. The OS time of patients in low-risk group was higher than that in high-risk group and the difference was statistically significant (P < 0.001). The AUC for this risk score was higher than other clinicopathological parameters, including TNM stage. This study presents an ARGs expression signature, which outperforms other clinicopathological parameters in predicting CRC prognosis.