Background: Colorectal cancer (CRC) involves the abnormal expression of a set of genetic and epigenetic genes, which may be useful for predicting prognosis. The transcription factor homeobox C9 (HOXC9) is a member of the homeobox family and participates in diverse cellular metabolic processes. In the current study, the prognostic value of HOXC9 in CRC was evaluated by analyzing public data from The Cancer Genome Atlas.
Methods: The correlation between clinical features and HOXC9 expression levels was evaluated by logistic regression. Kaplan-Meier and Cox regression was performed to determine the association between HOXC9 expression and patient prognosis. Gene set enrichment analysis was conducted to explore the function of HOXC9 in CRC. Results: HOXC9 showed higher expression in tumor tissue than in normal tissue. An increased level of HOXC9 in CRC was notably associated with an advanced tumor stage (OR = 1.58, for stage I/II vs. stage III/IV, p = 0.037), increased risk of distant metastasis (odds ratio = 1.84, for T1/T2 vs. T3/T4, p = 0.025), and tendency for venous invasion (OR = 2.25, p = 0.003). Kaplan-Meier analysis revealed that higher HOXC9 levels were predictive of poor overall (p = 0.0083) and progression-free survival (p = 0.0014). Multivariate COX regression model analysis proved that HOXC9 was independently associated with overall survival (hazard ratio = 2.88, 95% confidence interval: 1.14 - 7.29, p = 0.025). Gene set enrichment analysis showed that several biological function symbols were particularly enriched in the increased HOXC9 phenotype.
Conclusions: HOXC9 may play a critical role in CRC progression and serve as a novel potential marker of poor prognosis in CRC.