Hi,all I want to performe survival analysis to predict clinical outcome using genes from my gene set in TCGA data set (maybe I can call my gene set here as gene signature). Since I get my gene set by analyzing newly downloaded TCGA gene expression data, I want to performe survival analysis using the matched clinical data and not prefer to use available online tools (they may miss some important samples).
I read some papers which did the same things. I find that they may add some clinical parameters into survival analysis. For example, this paper (https://peerj.com/articles/1499/) added the age and tumor_grade into the survival analysis.
Should I add some clinical parameters as they did? or just use expression value?