Published online Jan 14, 2020. doi: 10.3748/wjg.v26.i2.134
Peer-review started: September 30, 2019
First decision: November 10, 2019
Revised: November 23, 2019
Accepted: December 7, 2019
Article in press: January 7, 2020
Published online: January 14, 2020
Processing time: 105 Days and 1.8 Hours
Hepatocellular carcinoma (HCC) is a common malignant tumor with a poor prognosis. In recent years, immunotherapy has emerged as a novel and effective therapy and is being applied in various tumors including HCC. However, the influence of genes involved in the tumor microenvironment on the prognosis of HCC patients remains unclear. And the high-throughput studies that investigated the potential prognostic role of immune prognostic models in HCC are still lacking.
So far, only a small number of HCC patients receiving immunotherapy treatment exhibited responses due to the immunosuppressive microenvironment. Hence, it is necessary to investigate the HCC microenvironment to identify prognostic genes that enable us to predict the benefit of immunotherapy, which may help in clinical decision making for individualized treatment.
To identify a robust gene signature associated with the HCC microenvironment to improve prognosis prediction and effectiveness of immunotherapy of HCC, we analyzed the data from The Cancer Genome Atlas (TCGA), Gene Expression Omnibus (GEO) and International Cancer Genome Consortium (ICGC) databases.
We computed the immune/stromal scores of HCC patients obtained from TCGA based on the ESTIMATE algorithm. Univariate analysis, multivariate analysis and the least absolute shrinkage and selection operator, were utilized to construct our predictive model. This model was performed based on the significant differentially expressed genes screened established based on mRNA expression profiles from the TCGA database. The robustness of this model was validated using GEO and ICGC datasets.
The risk score model consisting of eight genes (Disabled homolog 2, Musculin, C-X-C motif chemokine ligand 8, Galectin 3, B-cell-activating transcription factor, Killer cell lectin like receptor B1, Endoglin, and Adenomatosis polyposis coli tumor suppressor) was constructed and validated based on HCC patients who were divided into high- or low-risk group. The receiver operating characteristic curve analysis confirmd the good potency of the risk score prognostic model. Moreover, we investigated the relationship between patient risk scores and the expression of common immune checkpoints, and the results showed that the risk score was significantly associated with the expression of Cytotoxic T-Lymphocyte associated protein 4, Programmed cell death 1, and T-cell immunoglobulin mucin receptor 3. To establish a clinically applicable method to assess the prognosis of HCC patients, a nomogram involving risk score and the pathologic stage was formulated.
Our research established and validated a risk score model that is based on eight immune-related genes to predict the overall survival of HCC, which may help in clinical decision making for individualized treatment. The risk score model and the nomogram will benefit HCC patients through personalized immunotherapy.
The risk score model provides an immunological viewpoint to clarify the mechanisms that determine the clinical outcome of HCC. Identifying effective molecular biomarkers and predictive markers of immunotherapy is a future direction for improving the effectiveness of immunotherapy.