Sperm-Associated Antigen 9 as a Candidate Diagnostic and Prognostic Biomarker in Breast Cancer

Background: cancer/testis antigens are a unique class of tumor antigens with normal expressions restricted to the testis and various cancers, but not in adult somatic tissues. sperm-associated antigen 9 (spag9) has been introduced as a new member of cancer testis antigens family involved in c-jun-nh2-kinase signaling module.the objective of this research was to investigate the potential of spag9 as a diagnostic and prognostic biomarker in breast cancer. we further aimed to find any significant association between spag9 expression and clinicopathologic features of the cancer.methods: in this retrospective study, 35 breast cancer tissues and 35 adjacent non-cancerous tissues were collected and examined using rt-pcr to explore spag9 mrna expression. statistical analysis was done utilizing spss 22.0 software.results: unexpectedly, we detected spag9 expression in 54% of adjacent non-cancerous tissues. moreover, spag9 mrna was expressed in 57% of cancerous tissues. statistical analysis showed a significant association between spag9 expression and tumor size, lymph node metastasis, and cancer stage.conclusion: the association between the gene expression and tumor size, lymph, node and metastasis, and cancer stage suggests that spag9 can potentially be considered as a prognostic biomarker in breast cancer. however, it may not be a candidate diagnostic biomarker.