Abstract: Objective：To investigate the relationship between EMSY gene expression and polymorphism and prognosis in early ovarian epithelial cancer. Methods: 118 cases of early ovarian epithelial cancer (study group) and 63 patients with benign tumor (control group) were selected. EMSY mRNA was analyzed by RT-PCR, 421+242A＞G locus polymorphism was detected by PCR-RFLP, and the relationship between EMSY gene expression level and polymorphism and prognosis was further analyzed. Results: RT-PCR test showed that the relative expression of EMSY mRNA and BRCA2 mRNA of the study group were higher than those of the control group, the difference was statistically significant (t=33.592, P=0.000; t=25.046, P=0.000). Age, menopause, FIGO stage, differentiation degree, pathological type, postoperative chemotherapy and postoperative recurrence were associated with EMSY mRNA expression levels(P＜0.05). The frequency of the three genotypes and the two alleles of the EMSY gene 421+242A＞G locus in the study group were significantly different from those in the control group (P＜0.05), and the total survival rate of GG genotype and the progression free survival rate of 421+242A＞G locus of EMSY gene were statistically significant (Log-rank χ2=7.482, P=0.006; Log-rank χ2=8.406, P=0.004). High expression of EMSY mRNA affects the survival of the patient (OR=2.322, 95%CI: 1.277-5.031, P=0.027), and the AA genotype affects the progression free survival of the patients (OR=1.882, 95%CI: 1.192-4.323, P=0.039). Conclusions: EMSY gene expression and 421+242A＞G polymorphism are related to the prognosis of early ovarian cancer, which can be further studied.

Key words: Ovarian neoplasms, EMSY gene, Polymorphism, restriction fragment length, Prognosis