Significance of blood and salivary IEX‐1 expression in diagnosis of epithelial ovarian carcinoma

AIM: This study assesses a clinical potential of immediate early responsive gene X‐1 (IEX‐1), also named IER3, in the diagnosis of epithelial ovarian carcinoma using blood and salivary specimens. METHODS: Immediate early responsive gene X‐1 was quantified in blood and saliva by real‐time quantitative reverse transcription polymerase chain reaction in 26 cases of epithelial ovarian carcinoma, 37 cases of benign ovarian tumor and 55 cases of healthy women. The receiver operating characteristic (ROC) curve was used to evaluate the diagnostic efficacy of IEX‐1. RESULTS: Immediate early responsive gene X‐1 was expressed in blood and saliva of the benign ovarian tumor group and the healthy women group, both at a level significantly higher than that of the ovarian carcinoma group (P < 0.017). There were no significant differences in IEX‐1 expression in blood and saliva (P = 0.376 or 0.621, respectively) between the benign ovarian tumor and the healthy women group. Comparison of IEX‐1 expression in blood between the ovarian carcinoma group and the benign ovarian tumor group or the healthy women group demonstrated the ROC‐area under curves (AUC) of 0.947 or 0.929, respectively. In discriminating the ovarian carcinoma group from the benign ovarian tumor group, IEX‐1 expression in blood demonstrated a sensitivity and specificity of 84.6% and 94.6%, respectively. Similarly, blood IEX‐1 expression conferred a sensitivity of 84.6% and specificity of 90.9% in distinguishing the ovarian carcinoma group from the healthy women group. Moreover, salivary IEX‐1 expression had ROC‐AUC of 0.851 when compared between the ovarian carcinoma group and the benign ovarian tumor group or 0.896 when compared between the ovarian cancer group and the healthy women group. IEX‐1 expression was able to discriminate the ovarian carcinoma group from the benign ovarian tumor group with a sensitivity and specificity of 65.4% and 94.6%, respectively, or the ovarian carcinoma from the healthy women with 92.3% sensitivity and 72.5% specificity. CONCLUSION: These results suggest the clinical potential of IEX‐1 expression in blood and saliva as a sensitive and specific diagnosis for epithelial ovarian carcinoma.