Pair-Box (PAX8) protein-positive expression is associated with poor disease outcome in women with endometrial cancer

Background: The Pax8 transcription factor genes have a role in cell differentiation and cell growth, and silencing of Pax8 in cell cultures results in cell death. The aims of this study were to determine the expression and correlation of Pax8 protein with several clinicopathological variables in patients with endometrial cancer. Methods: The following clinical parameters from 229 patients were used for correlation with Pax8 expression; age, histological subtype, myometrial depth of invasion, lymphovascular invasion (LVI), the International Federation of Gynecology and Obstetrics grade, lymph nodes status, and disease status. Results: A positive association of Pax8 ⁺ expression was found with high tumour grade (P=0.002), LVI+(P=0.0186), and type II tumour subtype (P<0.0001) in univariate analysis. Survival analysis showed an association of Pax8 and 5-year overall survival probability (P=0.01486), 80.04% for patients with Pax8^- and 55.59% for patients with Pax8⁺. There was also an association of Pax8 and 5-year disease-free survival probability (P=0.02028), 72.12% for patients with Pax8^- vs 49.88% for patients with Pax8⁺. Finally, an association of Pax8⁺ and shorter recurrence-free survival was also found (P=0.00203), with 74.36% for Pax8^- and 52.11% for Pax8 ⁺. Conclusion: Overexpression of Pax8 protein by endometrial cancer is associated with poor disease outcomes. Inhibition of Pax8 may be a very attractive targeted therapy for selective patients.