Sperm-Associated Antigen 9 is a Promising marker for Early Diagnosis of Endometrial Cancer

Background: Sperm-associated antigen 9 (SPAG9) has been recently proposed as a novel biomarker for earlydiagnosis of several human tumors, including ovarian, cervical and breast cancers. Its clinical value remainsto be clarified for endometrial cancer (EC). In this study, we investigated the utility of serum SPAG9 levels indiagnosis of EC and its association with important clinicopathological parameters. Materials and
Methods:This cross-sectional study was performed at a tertiary women’s referral center in Ankara, Turkey. Preoperativeserum samples were collected from patients surgically treated for endometrial cancer between June 2012-April2013. Similar aged women with a biopsy proven benign endometrium were used as controls. Serum SPAG9levels were measured with an enzyme-linked immunosorbent assay (ELISA) method and assessed for linkswith clinicopathological factors. Receiver operating characteristic (ROC) curve analysis was performed toassess power of SPAG9 levels for EC prediction. P values less than 0.05 were considered statistically significant.
Results: A total of 63 women with EC and 27 with benign endometrium were included in the study. Mean agein the EC group was 58.7±1.1. Median SPAG9 levels in the EC and control groups were 18.3 (range, 12.7-53.8)and 14.1 (range, 4.3-65.3), respectively (p<0.001). A cut-off value of 17 ng/ml for SPAG9 predicted presence ofmalignant endometrium with 74% sensitivity and 83% specificity [Area under curve (AUC)=0.82, p<0.001].SPAG9 levels did not demonstrate any significant association with histological type, FIGO stage, tumor grade,size, myometrial invasion, lymphovascular space invasion, cervical involvement, adnexal involvement, peritonealcytology or lymph node status (all p>0.05).
Conclusions: Testing for SPAG9 may be useful for early detectionof EC in asymptomatic high-risk women. Its role in post-treatment follow-up and early detection of recurrenceshould be assessed in future trials.