BACKGROUND AND STUDY AIMSThe clinicopathological risk factors in the prognosis of stage IV gastric cancer have been comprehensively studied. However, the influencing factors of stage IV gastric cancer prognosis at genomic and transcriptional levels have not been well defined.PATIENTS AND METHODSThe mutational and transcriptional data, along with demographic, clinicopathological and prognostic information of 44 stage IV gastric cancer patients were downloaded from the TCGA database. Univariate and multivariate analyses were performed to identify the significant risk factors and a Nomogram model was established to predict the patient prognosis.RESULTSTTN, TP53, FLG, LRP1B, SYNE1 and ARID1A were among the top mutated genes without hot-spot mutations. The mutational status of AHNAK2, ASCC3, DNAH3, DOP1A, MYLK, SIPA1L1, SORBS2, SYNE1 and ANF462 significantly stratified the patient prognosis. The transcription of several genes, such as AQP10, HOXC8/9/10, COL10A1/COL11A1, WNT7B, KRT17 and KLK6 was significantly up-regulated or down-regulated. Enrichment analysis on mutations and transcription revealed cell skeleton and membrane function, extracellular matrix function, HPV infection, and several cancer-related pathways as the main aberrancies. Univariate analyses revealed a series of significant factors stratifying patient prognosis, mainly including cancer location, several mutated genes and many up- or down-regulated genes. However, subsequent multivariate analysis revealed SYNE1 mutation, DNAH3 mutation, COMMD3 transcription level, and cancer location as the independent risk factors. A Nomogram model has been established with these significant risk factors to predict the patient prognosis. Further validation is needed to ensure the effectiveness of the model in real clinical practice.CONCLUSIONSCancer location, along with the mutational status of SYNE1 and DNAH3 and the transcriptional level of COMMD3 were independent risk factors of stage IV gastric cancer. A Nomogram model was established with these factors for prognosis prediction.