High CD34 Expression Level Associated with Prolonged Liver and Stomach Cancer Survival

CD34 is a transmembrane phosphoglycoprotein that shows expression on early hematopoietic and vascular-associated tissues. Although tumor tissues usually possess upregulated CD34, little is known about this protein's exact function during the process of tumor development. Here, we carried out this study to find possible associations between tumor survival and the overexpressed CD34. We focused our data on patients with adenomas (and adenocarcinomas) occurring in liver or stomach, as these cancer types are common worldwide and contain a large amount of available patient statistics recorded in the TCGA database and we found that CD34 was among the group of proteins under significant upregulation in liver and stomach cancer. However, after constructing the survival curves comparing patient survival of high-level CD34 expression with low-level CD34 expression through a period of time, we observed that high CD34 expression level actually associates with a better tumor survival. This counter-intuitive relation between CD34 and patient survival rate implies a complicated cause-effect relationship behind, which suggests that the idea of designating CD34 as the target to develop therapies for treating cancer still needs more evaluations.